Woman fighting pneumonia holding a cup of tea



Last Section Update: 01/2017

Contributor(s): Maureen Williams, ND

1 Overview

Summary and Quick Facts for Pneumonia

  • Pneumonia is a lung infection. It causes cough, shortness of breath and fever. It can progress to severe breathing problems, especially in older people or people with suppressed immune systems.
  • This protocol will teach you about the causes of pneumonia and how the condition typically progresses. Learn what treatments are available and what steps to take to reduce the risk of getting pneumonia.
  • Since common infections like colds may progress to pneumonia, supplements like probiotics and Reishi mushroom, which help support immune function, may help reduce pneumonia risk. N-acetylcysteine (NAC) has been shown to improve inflammatory markers in people with pneumonia.

Pneumonia is an infection of the lungs that can cause cough, trouble breathing, and fever, with possible severe complications such as respiratory failure. In the United States, pneumonia is the sixth leading cause of death in people 65 and older, and causes about one million hospitalizations each year.

Fortunately, several integrative interventions such as pu-erh tea, cistanche, zinc, vitamin D, and probiotic supplements may help fortify the body’s defenses against infections like pneumonia.


  • Pneumonia is caused primarily by infectious organisms.
  • If immune defenses are impaired (as occurs with age-related immune senescence), then pathogens are more likely to establish an infection.

Risk Factors

Note: Proton-pump inhibitors are normally used to suppress stomach acidity for relief of gastroesophageal reflux. They may be a particularly problematic risk factor for pneumonia because their use is widespread and those taking them may be unaware that they are associated with significantly increased pneumonia risk.

Signs and Symptoms

  • Fever and chills
  • Chest or abdominal pain
  • Pain with breathing, shortness of breath
  • Cough, dry or with phlegm; cough producing green or yellow sputum
  • Night sweats
  • Rapid heart and breathing rate


Diagnosis is typically based on medical history, physical exam, chest X-ray, and a complete blood count.


  • Antibiotics are the mainstay of bacterial pneumonia treatment.
  • Adjunctive corticosteroids may improve outcomes and reduce complication risk
  • Vaccines targeting pneumococcal and influenza infections are the cornerstone of prevention.

Novel and Emerging Strategies

  • Using antibiotics for a short amount of time and not using them for viral infections may reduce the risk of inducing resistance.
  • A study on pneumonia patients admitted to a hospital showed that those who were chronic aspirin users were about half as likely to die within 30 days of hospital admission as those not taking aspirin.
  • The use of statins has been associated with decreased risk of pneumonia and pneumonia-related death, as well as reduced rates of acute bacterial infections.

Diet and Lifestyle Considerations

One of the most important ways to avoid pneumonia is to keep the immune system functioning normally.

  • Avoid smoking and excessive alcohol consumption.
  • Eat a nutrient-dense diet rich in unprocessed whole plant-based foods.
  • Exercise is thought to activate immune cells, help expel bacteria from the airways, and reduce stress.
  • Regular hand washing is recommended as a strategy for avoiding respiratory infections.
  • Maintain good oral health, because harmful bacteria in the mouth can be drawn into the lungs and cause infection.

Integrative Interventions

  • Probiotics: Probiotics may prevent hospital-acquired pneumonia in critically ill patients and lessen the incidence and duration of upper respiratory tract infections in healthy adults and children.
  • Vitamin D: People with the lowest vitamin D levels were 2.6 times more likely to develop pneumonia compared with those with the highest vitamin D levels in a study that followed older people for nearly 10 years.
  • Zinc: In a one-year study, nursing home residents with lower zinc status had almost twice the risk of pneumonia as those with normal zinc status.
  • Cistanche: Cistanche deserticola has been used historically in traditional Chinese medicine to stimulate immunity in the elderly.
  • Pu-erh tea: Pu-erh tea was found to enhance immune cell number while decreasing the inflammatory cytokine interleukin-6 in mice with immune senescence.

2 Introduction

Pneumonia is a potentially serious infection of the lungs that can cause cough, trouble breathing, and fever, with possible severe complications such as respiratory failure (Mayo Clinic 2015; Musher 2012; UMMC 2012). In the United States, pneumonia is the sixth leading cause of death in people 65 and older, and causes about one million hospitalizations each year (Musher 2012; Torres 2013; American Thoracic Society 2015).

The immune system weakens with age, a phenomenon known as immune senescence (Murray 2015). This leaves older individuals increasingly vulnerable to the bacteria and viruses that cause most cases of pneumonia (Krone 2014; Mayo Clinic 2015; Musher 2012). People with underlying medical conditions, such as chronic lung disease or heart disease, are also at increased risk (Torres, Peetermans 2013; Mayo Clinic 2015).

Antibiotics are the primary treatment for pneumonia and should be initiated when bacterial pneumonia is deemed probable (Musher 2012; Torres 2013). However, general overuse of antibiotics has driven the growing problem of antibiotic resistance, which can complicate pneumonia treatment (UMMC 2012). Pneumonia caused by drug-resistant bacteria is harder to treat and may lead to longer illness and greater risk of death (Bosso 2011).

Novel antibiotics and strategies to promote judicious antibiotic use, as well as campaigns to encourage broad uptake of pneumococcal vaccines among those 65 and older, are helping keep antibiotic resistance at bay to some degree. Nevertheless, innovative ways to prevent and manage infectious diseases like pneumonia are sorely needed (CDC 2015; Bosso 2011; Pinzone 2014).

Intriguing recent studies suggest an association between cholesterol-lowering statin drugs and reduced risk of pneumonia and pneumonia-related death, and adjunctive corticosteroids have been shown to reduce pneumonia severity (Nassaji 2015; Cheng 2014; Marti 2015; Horita 2015; Siemieniuk 2015). Also, history of aspirin use has been associated with reduced risk of death within 30 days of hospital admission with pneumonia (Falcone 2015).

In addition, several integrative interventions such as reishi mushroom (Lin 2005), pu-erh tea (Zhang 2012), cistanche (Wu 2005; Yamada 2010; Zhang 1988; Zhang 2014), zinc (Barnett 2010), vitamin D (Youssef 2012), and probiotic supplements (Hao 2015) may help fortify the body’s defenses against infections like pneumonia.

In this protocol you will learn about the causes of pneumonia and how this potentially fatal respiratory disease is typically managed. You will read about risk factors that could increase your vulnerability to pneumonia, and what lifestyle and dietary habits can help reduce your risk. Several novel and emerging pneumonia prevention and treatment strategies will be reviewed, and a number of natural interventions that may help mitigate pneumonia risk will be described. Given the significant contribution of immune senescence to pneumonia risk in the elderly, aging individuals should also review the Immune Senescence protocol.

3 Causes And Risk Factors

Pneumonia is caused primarily by infectious organisms. Pathogens can reach the lungs through inhalation of atmospheric air or can originate in secretions of the upper airways, which travel to the lungs. Rarely, microbes from other parts of the body move to the lungs via the bloodstream (Musher 2012). Although the lungs are constantly exposed to microbes, immune defenses usually prevent infection. However, if immune defenses are impaired (as occurs with age-related immune senescence), then pathogens are more likely to establish an infection (Brandenberger 2016; Simonetti 2014; Krone 2014).

Many infectious organisms can cause pneumonia, but the majority of community-acquired outpatient cases are attributable to the bacteria Streptococcus pneumoniae, Haemophilus influenzae, Legionella pneumophila, Staphylococcus aureus, and Mycoplasma pneumoniae and the influenza, parainfluenza, and respiratory syncytial viruses (Restrepo 2008; Marrie 2005; Cilloniz 2011; Torres 2013).

Pneumonia is categorized based on where it is contracted:

  • Community-acquired pneumonia is contracted outside of a hospital or other healthcare facility (ie, in the “community”), and often follows a viral respiratory infection such as a cold or the flu (Musher 2012; UMMC 2012).
  • Hospital-acquired pneumonia is contracted during hospitalization. It tends to be more dangerous than community-acquired pneumonia because hospitalized patients generally have weakened immune systems and infectious bacteria found in hospitals have a greater tendency to be antibiotic resistant (UMMC 2012). Mechanical ventilation is a major risk factor for a type of hospital-acquired pneumonia called ventilator-associated pneumonia.
  • Healthcare-associated pneumonia affects patients in long-term healthcare facilities or those being treated in healthcare clinics such as kidney dialysis centers. As with hospital-acquired pneumonia, healthcare-associated pneumonia tends to be more serious and involve more dangerous pathogens than community-acquired pneumonia (Mayo Clinic 2015). Some doctors may use the term hospital-acquired pneumonia to encompass all pneumonia contracted via contact with any healthcare facility.

Risk Factors

A weakened immune response, such as caused by age-related immune senescence, immunosuppressive medications, or HIV infection, increases pneumonia risk (UMMC 2012; Murray 2015; Krone 2014). People over age 65 are at increased risk of pneumonia (Musher 2012; Mayo Clinic 2015; Loeb 2003). Other pneumonia risk factors include (Musher 2012; Torres 2013; Mayo Clinic 2015; UMMC 2012; Paju 2007; Sura 2012; Lambert 2015):

  • Smoking
  • Acute infections, such as colds or the flu (For more information on the treatment and prevention of colds and the flu, see the Common Cold and Influenza protocols.)
  • Chronic diseases such as:
    • Chronic obstructive pulmonary disease (includes chronic bronchitis and emphysema)
    • Asthma
    • Diabetes
    • Cardiovascular disease
    • Liver disease
    • Chronic kidney disease
    • Cancer
    • Periodontal disease
    • Immune deficiency diseases
  • Drug or alcohol abuse
  • Neurological conditions that interrupt the gag reflex or impair swallowing, such as dementia and stroke
  • Use of certain medications, including corticosteroids, immunosuppressants, and proton-pump inhibitors, and overuse of antibiotics resulting in antimicrobial resistance. Proton-pump inhibitors, which are normally used to suppress stomach acidity for relief of gastroesophageal reflux, may be a particularly problematic risk factor for pneumonia because their use is widespread and those who take them may be unaware that they are associated with significantly increased pneumonia risk.

4 Signs And Symptoms


The usual symptoms of pneumonia are (UMMC 2012; Torres 2013; Sethi 2014):

  • Fever and chills (though fever is often not present in older individuals)
  • Chest or abdominal pain
  • Pain with breathing (pleurisy)
  • Cough, dry or with phlegm; cough producing green or yellow sputum
  • Night sweats
  • Flu-like symptoms such as nausea, vomiting, muscle aches, fatigue, headache, and loss of appetite
  • Shortness of breath
  • Rapid heart and breathing rate
  • Weight loss
  • Nausea, vomiting, diarrhea
  • Confusion may occur among older individuals

Symptoms often come on rapidly and may be severe. However, older patients with a weakened immune response may not have the usual array of pneumonia symptoms, instead presenting with fatigue, disorientation, or confusion (Musher 2012).


In severe pneumonia, bacterial infection can spread to the surrounding lung tissue, causing an abscess. Pneumonia can also cause fluid accumulation between the pleura (membranes that surround the lungs), a condition known as pleural effusion. In empyema, the fluid between the pleura becomes infected, which can lead to permanent scarring (UMMC 2012).

Pneumonia-causing bacteria can enter the bloodstream (bacteremia) and spread infection to other parts of the body including joints, bones, muscle groups, heart valves, the abdominal cavity, and the meninges that surround the brain and spinal cord (Musher 2012).

Respiratory failure, including acute respiratory distress syndrome, is a dangerous complication in which the lungs are unable to function properly, resulting in life-threateningly-low blood oxygen concentrations (UMMC 2012).

Pneumonia is associated with kidney complications including end stage renal failure (Huang 2014), and studies have linked pneumonia to increased risk of arrhythmias, heart attack, and worsening of heart failure (Musher 2012; Aliberti 2014). Prolonged bed rest resulting from pneumonia can lead to blood clots (Torres 2013).

5 Diagnosis

Diagnosis of mild-to-moderate community-acquired pneumonia is typically based on medical history, physical exam, chest X-ray, and a complete blood count (Aoun 2016). Pulse oximetry, a noninvasive test that measures the oxygen level in the blood, can help assess pneumonia severity and whether hospitalization is needed (Torres 2013; Ortega 2011; Kaysin 2016). White blood cell numbers are generally elevated in people with pneumonia, but can also be low in some cases of overwhelming bacterial infection. CT scan may also be helpful in certain ambiguous cases (UMMC 2012; Musher 2012; Sethi 2014; Aoun 2016). Sputum gram stain and culture can help identify the presence and species of bacteria (UMMC 2012; Musher 2012).

While identifying the infectious organism causing pneumonia can be helpful in choosing effective antibiotic treatment, physicians generally employ “empiric therapy” beginning immediately upon diagnosis of community-acquired pneumonia not requiring hospitalization (Cilloniz 2016). In empiric therapy, clinical judgment and knowledge of the patient and his or her condition guide treatment. This method is considered to have a high rate of success, and some authorities have recommended that attempts to identify the causative organism be reserved for more severe or problematic cases (Sethi 2014).

In hospitalized patients, blood cultures can reveal widespread bacterial infection, usually from Streptococcus pneumoniae (Sethi 2014). Specific blood tests for atypical organisms are available (Cilloniz 2016). Urine antigen tests can detect the presence of proteins from Streptococcus pneumoniae and Legionella pneumophila more rapidly than cultures (Sinclair 2013; Molinos 2015; Aoun 2016).

Invasive diagnostic procedures such as bronchoscopy or biopsy may be necessary in cases that do not respond to treatment as expected or in which unusual infectious organisms are suspected (Torres 2013).

6 Treatment

Antibiotics are the mainstay of bacterial pneumonia treatment. Guidelines for the management of community-acquired pneumonia published by the Infectious Diseases Society of America and the American Thoracic Society recommend initiating antibiotic therapy based on disease severity and the individual’s medical history rather than on microbial identification tests (Tedja 2013).

In previously healthy patients, usual first-line therapy includes antibiotics such as amoxicillin-clavulanic acid (Augmentin) or a macrolide antibiotic such as azithromycin, clarithromycin, or erythromycin. In patients with chronic health problems, recent antibiotic use, or other risk factors for drug-resistant bacterial infection, more aggressive treatment is preferred. These regimens are usually effective even when pneumonia is caused by infection with atypical bacteria such as Mycoplasma or Chlamydophila species (Simonetti 2014; Mandell 2007; Musher 2012).

All antibiotics, especially those with broad-spectrum activity, are associated with a range of possible side effects, from mild digestive upset to potentially life-threatening secondary intestinal infections such as Clostridium difficile colitis (Riddle 2009; Dallal 2002; Johanesen 2015).

Several analyses of trial data have found that adjunctive corticosteroids improve outcomes and reduce complication risk in community-acquired pneumonia. These benefits include a shorter length of hospital stay, reduced time to become clinically stable, reduced need for mechanical ventilation, and reduced risk of death in severe cases. These findings have led to recommendations that adjunctive corticosteroids be considered in hospitalized patients with severe community-acquired pneumonia if such treatment is not contraindicated (Siemieniuk 2015; Marti 2015; Horita 2015; Cilloniz 2016; Aoun 2016).

Viral pneumonia is often caused by influenza virus infection, though secondary bacterial pneumonia is a possible complication of viral pneumonia. Antiviral medications, including oseltamivir (Tamiflu) and zanamivir (Relenza), are sometimes used in these cases, though it is not certain that they can effectively treat established influenza virus pneumonia (Musher 2012; Chan 2016). Oseltamivir is associated with side effects including nausea and vomiting (Jefferson 2014).

In cases of severe pneumonia or in patients at high risk of complications, the physician may choose to recommend hospitalization so oxygen, ventilation assistance, and intravenous antibiotics and fluids can be provided (Black 1991; Fine 1990; Mandell 2007; Musher 2012).

Vaccination for Pneumonia Prevention

Vaccines targeting pneumococcal and influenza infections are the cornerstone of medical prevention of community-acquired pneumonia (Mandell 2007). Annual influenza vaccines reduce rates of influenza infections and influenza-associated pneumonia, as well as pneumonia complications and pneumonia hospitalizations (Grijalva 2015; Ridenhour 2013; Simpson 2013; Song 2015). The influenza vaccine is considered especially important for the elderly and other high-risk individuals (Song 2015).

Two pneumococcal vaccines, a 23-valent pneumococcal polysaccharide vaccine (Pneumovax®23) and a 13-valent pneumococcal conjugate vaccine (Prevnar13®) are available and generally recommended for people aged 65 and older and for all high-risk adults (NFID 2014; CDC 2016). The pneumococcal conjugate vaccine, in particular, is effective in eliciting an immune response in people with immune senescence (Kwetkat 2015; van Werkhoven 2015; de Roux 2008). A randomized controlled trial published in 2015, which enrolled nearly 85 000 volunteers aged 65 or older, found that PCV13 was effective in preventing community-acquired pneumonia and invasive pneumococcal disease caused by organisms against which the vaccine is designed to protect (Bonten 2015).

Pneumococcal vaccines also help combat antibiotic resistance, which can help reduce the prevalence of invasive disease caused by difficult-to-treat pneumococcal infections (Lipsitch 2016). Intriguingly, a meta-analysis found that use of the pneumococcal polysaccharide vaccine was associated with a significantly reduced risk of acute coronary syndrome in adults 65 and older (Ren 2015).

7 Novel And Emerging Strategies

Antimicrobial Stewardship

It is widely accepted that inappropriate and excessive antibiotic use has contributed to the emergence of increasing numbers of drug-resistant bacteria (Bosso 2011; Pinzone 2014; Roca 2015). Researchers in one extensive study found that approximately 25% of all Streptococcus pneumoniae samples were multidrug resistant, while another study found that more than 50% of Staphylococcus aureus samples isolated from patients with infections including pneumonia were multidrug resistant (Thornsberry 2008; Aliberti 2013). In regions with high antibiotic prescribing rates, resistant strains of Streptococcus pneumoniae are more common (Hicks 2011). The rising presence of resistant strains poses treatment challenges as well as public health dangers (Bosso 2011; Roca 2015).

The goal of antibiotic stewardship is to maximize beneficial clinical outcomes while minimizing negative and unintentional consequences of antimicrobial use. Adverse effects that judicious antimicrobial use may minimize include Clostridium difficile infections and multidrug-resistance (Dellit 2007; Barlam 2016).

A review of 14 scientific papers examining the application of the principles of antimicrobial stewardship in community-acquired pneumonia found an increase in appropriate antimicrobial use and a reduction in unnecessary antimicrobial prescribing. This was associated with better patient outcomes, including reduced 30-day and in-hospital mortality, shorter hospital stays, and reduced treatment failure rates and healthcare costs. A decrease in antimicrobial resistance was also observed (Bosso 2011).

Another strategy that is gaining attention is the use of shorter courses of some antibiotics in appropriate situations. Minimizing exposure to antibiotics may reduce the risk of inducing resistance (Rubinstein 2013). Short courses ranging from three to seven days have been found to be as effective for treating community-acquired pneumonia as a traditional 10-day course, but with lower risk of antibiotic-related adverse effects. This strategy also holds promise to decrease the risk of emergence of treatment-resistant organisms (Pinzone 2014).


Aspirin interacts with omega-3 fatty acid metabolic pathways to promote the formation of specialized inflammation-resolving molecules called “resolvins.” Resolvins and related molecules appear to be involved in the resolution of inflammatory conditions such as pneumonia (Serhan 2004; Oh 2011; Arita 2005). An animal model suggested that an aspirin-triggered resolvin exerts antibacterial activity in a model of pneumonia and could complement antibiotic therapy (Abdulnour 2016). A study on 1005 pneumonia patients admitted to a hospital in Italy with community-acquired pneumonia showed that those who were chronic aspirin users were about half as likely to die within 30 days of hospital admission as those not taking aspirin (Falcone 2015).

One serious complication of severe pneumonia is acute coronary syndrome, which occurs when the heart does not get enough blood flow (AHA 2015). One randomized open-label study enrolled 185 pneumonia patients upon hospital admission. Ninety-one of the participants received aspirin, while 94 served as a control group. The rate of acute coronary syndrome in the control group during the 30 days following admission was 10.6%, while the corresponding rate in the aspirin-treated group was only 1.1%. In addition, the aspirin recipients were significantly less likely to die from cardiovascular causes (Oz 2013).


In keeping with the goal of reducing antibiotic use, non-antibiotic treatments for pneumonia are an area of active investigation. The use of statins, a class of cholesterol-lowering medication, has been associated with decreased risk of pneumonia and pneumonia-related death, as well as reduced rates of acute bacterial infections (Nassaji 2015; Lin, Chang 2016; Cheng 2014; Terblanche 2007). Statins appear to inhibit lung inflammation through modulation of neutrophil activity, inhibition of inflammatory cytokines such as nuclear factor-kappa B, and induction of an enzyme that limits oxidative stress. One study evaluated the association between statin use and efferocytosis, an inflammation-resolving process involved in recovery from pneumonia, in 22 community-acquired pneumonia patients in London. This study found that statin use was associated with higher rates of efferocytosis, an effect that was most prominent in smokers (Wootton 2016). Also, community-acquired pneumonia is associated with an increased risk of cardiovascular events, and individuals taking statins may have some protection from this risk. Further studies will be required to clarify the potential role of statins in preventing and treating pneumonia and its complications (Troeman 2013; Feldman 2015).

Blood Procalcitonin Testing to Guide Antibiotic Therapy

Elevated blood levels of a protein called procalcitonin are suggestive of a bacterial infection (Musher 2012). Along with consideration of the patient’s clinical status, measuring procalcitonin levels may help guide antibiotic therapy decisions in patients with community-acquired pneumonia (Pinzone 2014; Montassier 2013). One analysis suggested that using procalcitonin testing to determine if antibiotics should be administered reduced total antibiotic exposure and duration of antibiotic treatment (Christ-Crain 2006). Another analysis showed that procalcitonin-guided antibiotic prescribing to patients with respiratory infections, including pneumonia, reduced the median duration of antibiotic exposure by half (Schuetz 2012).

8 Diet And Lifestyle Considerations

Many cases of community-acquired pneumonia begin with a simple cold or a flu (van der Sluijs 2010; Lee 2010; NLM 2016a). Thus, one of the most important ways to avoid pneumonia is to maintain good overall health and keep the immune system functioning normally (Musher 2012; Craig 2009; NLM 2016b; ALA 2016). For more information on ways to avoid the cold and flu, see Life Extension’s Common Cold and Influenza protocols.

  • Avoid smoking and excessive alcohol consumption. Smoking is the most important risk factor for community-acquired pneumonia that is under an individual’s control. Also, excessive alcohol consumption increases the risk of community-acquired pneumonia (Almirall 2015).
  • Healthy diet. Nutrient deficiencies and malnutrition are common in older people and contribute to pneumonia risk (Ahmed 2010; Evans 2005; Gaillat 2003), but may be preventable through a well-rounded nutrient-dense diet and dietary supplementation (Stechmiller 2003; Park 2008; Guyonnet 2015).
  • Exercise. Substantial evidence indicates engaging in regular physical activity diminishes some of the negative effects of aging on immune cell activity (Senchina 2007) and physically active seniors have fewer infections than their sedentary counterparts (Simpson 2010). Exercise is thought to exert these benefits by activating immune cells, helping expel bacteria from the airways, and reducing stress (NLM 2014).
  • Basic hygiene. Regular hand washing is recommended as a strategy for avoiding respiratory infections (UMMC 2012). Regular water or saline nasal irrigation may also help keep respiratory infections at bay (AFP 2009).

Once pneumonia has set in, adequate water intake is especially important for keeping the mucus in the lungs loose. In addition, getting plenty of rest until symptoms are completely resolved may help prevent recurrence (Mayo Clinic 2015).

Poor Oral Health Increases Pneumonia Risk

Because harmful bacteria in the mouth can be aspirated into the lungs and cause infection (Barnes 2014), poor oral hygiene is associated with a higher risk of pneumonia (Torres, Peetermans 2013; Raghavendran 2007; El Attar 2010).

One study that assessed the rate of respiratory illness among a group of older adults demonstrated the importance of thorough oral hygiene. During a six-month period, only 1 of 98 aging adults who utilized dental hygienists for oral health care developed respiratory infections, compared with 9 of 92 people who did not receive the same preventative dental care (Adachi 2007).

In addition, a daily water gargling habit has been found to reduce the incidence of upper respiratory tract infections, perhaps by keeping infectious microbes from sticking to the oral surfaces (Satomura 2005). Gargling with salt water may also prevent respiratory tract infections, which often precede pneumonia (Emamian 2013).

Several strategies for maintaining good oral health are described in Life Extension’s Oral Health protocol.

9 Nutrients

Note: In addition to reviewing the integrative interventions described here, readers are encouraged to review those described in the Immune Senescence protocol. Immune senescence is an important risk factor for pneumonia, and, therefore, natural compounds shown to combat immune senescence may help reduce pneumonia risk. Similarly, because colds and the flu are risk factors for pneumonia, the Common Cold and Influenza protocols should be consulted as well.


When hospitalized patients require assisted ventilation for 48 hours or more, their risk of developing hospital-acquired pneumonia increases (Liu 2012). Meta-analyses of randomized controlled trial data have concluded that probiotics may prevent hospital-acquired pneumonia in critically ill patients (Liu 2012; Barraud 2013; Petrof 2012; Bo 2014) and lessen the incidence and duration of upper respiratory tract infections in healthy adults and children (Hao 2015; King 2014; Saeterdal 2012). A double-blind placebo-controlled clinical trial on more than 200 healthy subjects tested whether probiotic formulas impacted the rate and severity of respiratory illness over three winters. The trial used formulas containing multiple strains of Lactobacilli (including Lactobacillus plantarum LP 02-LMG P-21020), as well as Bifidobacterium lactis BS 01-LMG P-21384. The frequency, severity, and duration of respiratory illnesses during cold and flu season were significantly reduced in the probiotic group compared with the placebo group (Pregliasco 2008). Since many cases of bacterial pneumonia are preceded by upper respiratory tract infections (Musher 2012), preventing these milder infections may reduce pneumonia risk. Probiotics are also useful in minimizing side effects of antibiotic therapy, including diarrhea and Clostridium difficile infection (Urben 2014; Maziade 2015). 


Ganoderma lucidum, commonly known as reishi or lingzhi, has a long history of use for treating conditions related to inflammation and low immune function (Suarez-Arroyo 2013; Wachtel-Galor 2011; Patel 2012; Batra 2013). Because of its balancing effect on immune activity, reishi is considered an immune modulator (Bhardwaj 2014). Reishi polysaccharides have been found to stimulate infection-fighting immune cells (Tsai 2012; Zhu 2005).


Cistanche deserticola has been used historically in traditional Chinese medicine to stimulate immunity in the elderly. Cistanche glycosides, including the compound echinacoside, as well as a cistanche polysaccharide have demonstrated immune-enhancing effects (Xuan 2008; Wu 2005; He 2009). An extract of cistanche was found to increase lifespan and stimulate immune cell activity in mice with immune senescence. Because immune senescence plays a key role in pneumonia susceptibility in older individuals (Krone 2014; McElhaney 2012; Murray 2015; Zhang 2014), cistanche holds promise as a pneumonia preventive in the elderly.

Pu-erh Tea

Pu-erh tea has been used traditionally in China for centuries for a wide range of health benefits. Pu-erh tea was found to enhance immune cell activity while decreasing the inflammatory cytokine interleukin-6 in mice with immune senescence (Zhang 2012). This immune-modulatory effect gives pu-erh tea potential as a pneumonia preventive in aging individuals.

Vitamin D

Data from the National Health and Nutrition Examination Survey III showed occurrence of community-acquired pneumonia was higher in people with low vitamin D status (Quraishi 2013). In another study that followed over 1400 people between the ages of 53 and 73 for an average of almost 10 years, those with the lowest vitamin D levels were 2.6 times more likely to develop pneumonia compared with those with the highest vitamin D levels (Aregbesola 2013). Very low (< 15 ng/mL) 25-hydroxyvitamin D levels have been associated with 2.6-fold greater odds of hospitalization for community-acquired pneumonia (Jovanovich 2014). Furthermore, vitamin D deficiency may increase the risk of death in hospitalized patients with community-acquired pneumonia (Kim 2015; Leow 2011). An ongoing randomized, placebo-controlled, double-blind clinical trial, called the Lung VITAL study, is examining whether supplementing with 2000 IU vitamin D plus 1 g omega-3 fatty acids from fish per day can reduce pneumonia risk (Gold 2016). An analysis of randomized controlled trial data found vitamin D supplementation reduced the odds of respiratory infections by over 40% (Charan 2012).

These benefits may be partly explained by vitamin D’s ability to increase antimicrobial immune activity (Borella 2014; Youssef 2012). Also, vitamin D deficiency is associated with fewer immune cells in the blood, increasing susceptibility to infection (Dogan 2009; Youssef 2012). Vitamin D is also an immune modulator, involved in stimulating innate immune activity and regulating tissue-damaging inflammation (Youssef 2012; Lin 2016; Calton 2015).


Poor zinc status, a common finding in the elderly, is associated with impaired immune function, decreased defenses against microbes, increased duration and incidence of pneumonia, and greater use of antimicrobial treatments. Low zinc levels are also associated with an increased rate of death from all causes in the elderly. Because zinc is needed for normal cell division and development, it is especially important to cells that replicate rapidly, such as immune cells (Barnett 2010). 

In a one-year study, nursing home residents with lower zinc status were found to have almost twice the risk of pneumonia as those with normal zinc status. In addition, pneumonia lasted longer and more antibiotics were used in the low-zinc residents compared with their normal-zinc counterparts. Study subjects with adequate zinc levels were at a significantly lower risk of dying from any cause (Meydani 2007). In an animal model, mice fed a zinc-deficient diet were dramatically more likely to die of infection with Streptococcus pneumoniae, and to have evidence of lung infection with Streptococcus pneumoniae, compared with mice fed zinc-adequate diets (Strand 2001).

Zinc supplements may reduce the duration and severity of upper respiratory tract infections. In one trial, volunteers with recent onset of cold symptoms were treated with 13.3 mg zinc, in the form of an oral zinc acetate lozenge, or placebo every 2–3 hours during the day. Zinc-treated subjects had less severe symptoms and recovered an average of 3.1 days sooner than placebo-treated subjects (Prasad 2008). In a similar trial, taking a lozenge providing 12.8 mg zinc acetate every 2–3 hours, beginning within 24 hours of developing a cold, was associated with decreased severity of symptoms and a 3.6-day reduction in duration of symptoms (Prasad 2000). Zinc may also be useful in prevention. A randomized controlled clinical trial in adults aged 55–87 found daily supplementation with 45 mg zinc gluconate for 12 months was associated with lower incidence of infections compared with placebo (Prasad 2007). Since pneumonia is often a complication of an upper respiratory tract infection (Musher 2012), preventing colds or reducing their severity may help protect against pneumonia.

Vitamin E

In a one-year controlled clinical trial, over 600 elderly nursing home residents were treated daily with 200 IU vitamin E or placebo. Those receiving vitamin E experienced fewer common colds (Meydani 2004). Another study following elderly patients hospitalized with community-acquired pneumonia found taking vitamin E supplements was associated with 63% lower odds of re-hospitalization after discharge (Neupane 2010). Based on work in animal models of susceptibility to infection in the elderly, vitamin E appears to exert its protective effect against bacterial pneumonia through modulation of immune function (Bou Ghanem 2015).

Vitamin E is not a single compound, but rather comprises several related compounds called isoforms (Abdala-Valencia 2013). A combination of natural tocopherols may possess greater health-promoting properties compared with isolated alpha-tocopherol. Gamma-tocopherol in particular seems to be an important contributor to some of vitamin E’s health benefits (Peh 2016; Mathur 2015; Devaraj 2008; Lee 2009; Wu 2007).

Green Tea

Green tea is rich in polyphenolic compounds called catechins (Taylor 2005). A major catechin in green tea, epigallocatechin gallate or EGCG, has demonstrated antiviral action against influenza virus (Ling 2012) and has been shown to activate antibacterial immunity against Legionella pneumophila in vitro (Matsunaga 2002; Yamamoto 2004). Green tea catechins have demonstrated important antimicrobial activity against oral pathogens that cause periodontal disease, which may be a risk factor for development of bacterial pneumonia (Taylor 2005; Raghavendran 2007).

A study that followed older subjects for 12 years found that women who drank one or more cups (averaging about 3.5 fl oz per cup) of green tea per day were 41–47% less likely to die from pneumonia than women who drank less than one cup of green tea per day (Watanabe 2009). Drinking 1–5 cups of green tea daily was found in another study to reduce the risk of influenza, a common prelude to pneumonia, in schoolchildren (Park 2011; Chan 2016).

In a controlled clinical trial in nearly 200 healthcare workers, a green tea extract providing 378 mg per day of green tea catechins and 210 mg per day of the green tea-derived amino acid theanine was compared with placebo. Subjects in the green tea extract group had 75% fewer influenza infections over a five-month period (Matsumoto 2011). Gargling with a catechin-rich green tea extract may also be an effective way to prevent respiratory infections, including influenza. In a 3-month study, 148 nursing home residents were assigned to gargle regularly with either a solution containing green tea catechins or a catechin-free control solution. Only 1.3% of residents in the catechin group contracted influenza, while 10% of those in the control group became ill with the flu (Yamada 2006).

N-acetylcysteine and L-cystine

N-acetylcysteine (NAC) is a precursor to glutathione, one of the body’s essential oxidative stress modulators, and has been studied in bronchitis, cystic fibrosis, and other lung conditions because of its expectorant and mucus-thinning actions (van Zandwijk 1995; Tirouvanziam 2006; Roxas 2007; Chen 2013). NAC supplementation increases the body’s stores of glutathione, and evidence indicates that NAC improves immunity and modulates inflammation (McCarty 2015). In a six-month trial with 262 participants, most of whom were 65 or older, only 25% of those taking 600 mg NAC twice daily developed influenza symptoms compared with 79% of those in the placebo group. NAC treatment significantly decreased the severity and frequency of influenza-like episodes, and reduced time spent recovering in bed (De Flora 1997). Influenza often precedes community-acquired pneumonia (Musher 2012), suggesting that NAC might offer some protection against pneumonia in older adults.

A combination of L-cystine and another amino acid, L-theanine (found in green tea), may also protect against viral infections that could lead to pneumonia (Jain 2016; Soboleva 2004; Boros 2016). Taken daily for 14 days prior to vaccination, 700 mg L-cystine plus 280 mg L-theanine improved immune response to the influenza vaccine to a greater degree than placebo in nursing home residents (Miyagawa 2008). In another trial, healthy men taking 350 mg L-cystine plus 140 mg L-theanine twice daily had 58% fewer colds in a 35-day period than those taking placebo (Kurihara 2010).


Echinacea is an immunomodulator that can stimulate antimicrobial immune function but inhibit overly inflammatory immune activity (Zhai 2007; Goel 2005). A rigorous analysis of randomized controlled trials of echinacea preparations concluded that echinacea use can prevent repeated respiratory infections and their complications, including pneumonia. The analysis also determined that using higher doses of echinacea during infections improved its efficacy (Schapowal 2015).

Preliminary research suggests early treatment of cold symptoms with echinacea may speed recovery (Lindenmuth 2000; Goel 2005). Early treatment of influenza with an echinacea preparation was found to be as effective as the antiviral medication oseltamivir (Raus 2015).

Individuals at high risk of pneumonia due to chronic respiratory conditions may benefit from the use of echinacea. In a pilot trial, adults with pre-existing chronic respiratory conditions were treated with either influenza vaccine, a standardized echinacea extract, or both. Those treated with the echinacea extract, with and without the flu shot, experienced fewer flu-like symptoms and had fewer respiratory complications during the study period compared with those who received only the vaccine (Di Pierro 2012).

Vitamin C

Some trials have found a benefit of vitamin C supplementation in the prevention of pneumonia, and a review of trials of vitamin C for the common cold found a reduction in severity and duration of colds (Hemila, Chalker 2013; Hemila, Louhiala 2013). Serum levels of vitamin C have been found to be lower in patients with pneumonia than in healthy people (Bakaev 2004). Even a modest dose of 200 mg per day has been shown to raise serum levels and improve the symptomatic condition of individuals with acute respiratory infections (Hunt 1994). Vitamin C has been shown to reduce oxidative stress and levels of inflammatory biomarkers in a preclinical model of severe community-acquired pneumonia (Chen 2014).


In a controlled clinical trial lasting 12 weeks during winter, volunteers taking a garlic supplement had fewer and shorter colds than volunteers taking a placebo (Josling 2001). In another randomized controlled trial, healthy subjects taking an aged garlic extract reported fewer and less severe cold and flu symptoms, and less school and work days missed, during the 3-month study period compared with placebo. Furthermore, blood tests after 45 days showed superior immune cell proliferation in the garlic extract group compared with placebo (Nantz 2012). In a preclinical study, garlic extract demonstrated antibacterial action against both Streptococcus pneumoniae and a less common cause of pneumonia, Klebsiella pneumoniae (Dikasso 2002). A randomized controlled trial published in 2016 investigated the effect of aged garlic extract supplementation on the incidence and severity of colds and the flu. Participants (n=120) were randomized to receive aged garlic extract (2.56 g daily) or placebo for 90 days during cold and flu season. After 45 days, specialized cytotoxic T cells called gamma-delta T cells and NK cells from the garlic recipients proliferated better and were more activated than those from placebo recipients. After 90 days, those who received aged garlic extract reported reduced cold and flu severity, fewer symptoms, and less absenteeism from work and school (Percival 2016).

Coenzyme Q10

Coenzyme Q10 (CoQ10) is found in all metabolically active cells of the body. Supplemental CoQ10 may benefit people with pneumonia by inhibiting inflammation, improving cellular energy metabolism, and modulating oxidative stress. In one randomized controlled clinical trial, older adults hospitalized with community-acquired pneumonia were given either 200 mg CoQ10 daily or placebo, in addition to antibiotics, for 14 days. At the end of the trial, it was noted that fevers had resolved more quickly, hospital stays were shorter, recovery rates were higher, and treatment failure rates were lower in the CoQ10 group compared with the placebo group (Farazi 2014).


  • Jan: Comprehensive update & review

Disclaimer and Safety Information

This information (and any accompanying material) is not intended to replace the attention or advice of a physician or other qualified health care professional. Anyone who wishes to embark on any dietary, drug, exercise, or other lifestyle change intended to prevent or treat a specific disease or condition should first consult with and seek clearance from a physician or other qualified health care professional. Pregnant women in particular should seek the advice of a physician before using any protocol listed on this website. The protocols described on this website are for adults only, unless otherwise specified. Product labels may contain important safety information and the most recent product information provided by the product manufacturers should be carefully reviewed prior to use to verify the dose, administration, and contraindications. National, state, and local laws may vary regarding the use and application of many of the therapies discussed. The reader assumes the risk of any injuries. The authors and publishers, their affiliates and assigns are not liable for any injury and/or damage to persons arising from this protocol and expressly disclaim responsibility for any adverse effects resulting from the use of the information contained herein.

The protocols raise many issues that are subject to change as new data emerge. None of our suggested protocol regimens can guarantee health benefits. Life Extension has not performed independent verification of the data contained in the referenced materials, and expressly disclaims responsibility for any error in the literature.

Abdala-Valencia H, Berdnikovs S, Cook-Mills JM. Vitamin E isoforms as modulators of lung inflammation. Nutrients. Nov 2013;5(11):4347-4363.

Abdulnour RE, Sham HP, Douda DN, et al. Aspirin-triggered resolvin D1 is produced during self-resolving gram-negative bacterial pneumonia and regulates host immune responses for the resolution of lung inflammation. Mucosal immunology. Sep 2016;9(5):1278-1287.

Adachi M, Ishihara K, Abe S, Okuda K. Professional oral health care by dental hygienists reduced respiratory infections in elderly persons requiring nursing care. International journal of dental hygiene. May 2007;5(2):69-74.

AFP. Saline Nasal Irrigation for Upper Respiratory Conditions. American family physician. Nov 15 2009;80(10):1117-1119.

AHA. American Heart Association. Conditions: Acute Coronary Syndrome. http://www.heart.org/HEARTORG/Conditions/HeartAttack/AboutHeartAttacks/Acute-Coronary-Syndrome_UCM_428752_Article.jsp#. 7/2015. Accessed 12/9/2016

Ahmed T, Haboubi N. Assessment and management of nutrition in older people and its importance to health. Clinical interventions in aging. 2010;5:207-216.

ALA. American Lung Association. Lung Health & Diseases. Learn About Pneumonia. http://www.lung.org/lung-health-and-diseases/lung-disease-lookup/pneumonia/learn-about-pneumonia.html. Copyright 2016. Accessed 6/28/2016.

Aliberti S, Kaye KS. The changing microbiologic epidemiology of community-acquired pneumonia. Postgrad Med. Nov 2013;125(6):31-42.

Aliberti S, Ramirez JA. Cardiac diseases complicating community-acquired pneumonia. Current opinion in infectious diseases. Jun 2014;27(3):295-301.

Almirall J, Serra-Prat M, Bolibar, I. "Community-acquired pneumonia in adults" Recommendations for its prevention. Community Acquired Infection. 2015;2(2):32–37.

American Thoracic Society. Top 20 Pneumonia Fatcs. https://www.thoracic.org/patients/patient-resources/resources/top-pneumonia-facts.pdf. Copyright 2015. Accessed 12/14/2016.

Aoun N. Ferri's Clinical Advisor. Pneumonia, Bacterial. www.clinicalkey.com. Copyright 2016 Elsevier, Inc. Accessed 6/23/2016

Aregbesola A, Voutilainen S, Nurmi T, Virtanen JK, Ronkainen K, Tuomainen TP. Serum 25-hydroxyvitamin D3 and the risk of pneumonia in an ageing general population. J Epidemiol Community Health. Jun 2013;67(6):533-536.

Arita M, Clish CB, Serhan CN. The contributions of aspirin and microbial oxygenase to the biosynthesis of anti-inflammatory resolvins: novel oxygenase products from omega-3 polyunsaturated fatty acids. Biochemical and biophysical research communications. Dec 09 2005;338(1):149-157.

Bakaev VV, Duntau AP. Ascorbic acid in blood serum of patients with pulmonary tuberculosis and pneumonia. The international journal of tuberculosis and lung disease : the official journal of the International Union against Tuberculosis and Lung Disease. Feb 2004;8(2):263-266.

Barlam TF, Cosgrove SE, Abbo LM, et al. Implementing an Antibiotic Stewardship Program: Guidelines by the Infectious Diseases Society of America and the Society for Healthcare Epidemiology of America. Clinical Infectious Diseases. April 13, 2016.

Barnes CM. Dental hygiene intervention to prevent nosocomial pneumonias. The journal of evidence-based dental practice. Jun 2014;14 Suppl:103-114.

Barnett JB, Hamer DH, Meydani SN. Zinc: a new risk factor for pneumonia in the elderly? Nutrition reviews. 2010;68(1):30-37.

Barraud D, Bollaert PE, Gibot S. Impact of the administration of probiotics on mortality in critically ill adult patients: a meta-analysis of randomized controlled trials. Chest. Mar 2013;143(3):646-655.

Batra P, Sharma AK, Khajuria R. Probing Lingzhi or Reishi medicinal mushroom Ganoderma lucidum (higher Basidiomycetes): a bitter mushroom with amazing health benefits. International journal of medicinal mushrooms. 2013;15(2):127-143.

Bhardwaj N, Katyal P, Sharma AK. Suppression of inflammatory and allergic responses by pharmacologically potent fungus Ganoderma lucidum. Recent patents on inflammation & allergy drug discovery. 2014;8(2):104-117.

Black ER, Mushlin AI, Griner PF, Suchman AL, James RL, Jr., Schoch DR. Predicting the need for hospitalization of ambulatory patients with pneumonia. Journal of general internal medicine. Sep-Oct 1991;6(5):394-400.

Bo L, Li J, Tao T, et al. Probiotics for preventing ventilator-associated pneumonia. The Cochrane database of systematic reviews. 2014;10:Cd009066.

Bonten MJ, Huijts SM, Bolkenbaas M, Webber C, Patterson S, Gault S, . . . Grobbee DE. Polysaccharide conjugate vaccine against pneumococcal pneumonia in adults. The New England journal of medicine. Mar 19 2015;372(12):1114-1125.

Borella E, Nesher G, Israeli E, Shoenfeld Y. Vitamin D: a new anti-infective agent? Annals of the New York Academy of Sciences. May 2014;1317:76-83.

Boros K, Jedlinszki N, Csupor D. Theanine and Caffeine Content of Infusions Prepared from Commercial Tea Samples. Pharmacognosy magazine. Jan-Mar 2016;12(45):75-79.

Bosso JA, Drew RH. Application of antimicrobial stewardship to optimise management of community acquired pneumonia. International journal of clinical practice. Jul 2011;65(7):775-783.

Bou Ghanem EN, Clark S, Du X, Wu D, Camilli A, Leong JM, Meydani SN. The alpha-tocopherol form of vitamin E reverses age-associated susceptibility to streptococcus pneumoniae lung infection by modulating pulmonary neutrophil recruitment. J Immunol. Feb 1 2015;194(3):1090-1099.

Brandenberger C, Muhlfeld C. Mechanisms of lung aging. Cell and tissue research. Oct 14 2016.

Calton EK, Keane KN, Newsholme P, Soares MJ. The Impact of Vitamin D Levels on Inflammatory Status: A Systematic Review of Immune Cell Studies. PloS one. 2015;10(11):e0141770.

CDC. Centers for Disease Control and Prevention. Pneumococcal Disease: Drug Resistance. http://www.cdc.gov/pneumococcal/drug-resistance.html. Last updated 6/10/2015. Accessed 5/26/2016.

CDC. Centers for Disease Control and Prevention. Pneumococcal Vaccination. https://www.cdc.gov/vaccines/vpd/pneumo/index.html. Last updated 12/14/2016. Accessed 12/14/2016.

Chan PA. Ferri's Clinical Advisor. Pneumonia, Viral. www.clinicalkey.com. Copyright 2016 Elsevier, Inc. Accessed 6/23/2016

Charan J, Goyal JP, Saxena D, Yadav P. Vitamin D for prevention of respiratory tract infections: A systematic review and meta-analysis. Journal of pharmacology & pharmacotherapeutics. Oct 2012;3(4):300-303.

Chen Y, Dong H, Thompson DC, Shertzer HG, Nebert DW, Vasiliou V. Glutathione defense mechanism in liver injury: insights from animal models. Food and chemical toxicology: an international journal published for the British Industrial Biological Research Association. Oct 2013;60:38-44.

Chen Y, Luo G, Yuan J, et al. Vitamin C mitigates oxidative stress and tumor necrosis factor-alpha in severe community-acquired pneumonia and LPS-induced macrophages. Mediators Inflamm. 2014;2014:426740.

Cheng HH, Tang TT, He Q, et al. Beneficial effects of statins on outcomes in pneumonia: a systematic review and meta-analysis. European review for medical and pharmacological sciences. Aug 2014;18(16):2294-2305.

Christ-Crain M, Stolz D, Bingisser R, et al. Procalcitonin guidance of antibiotic therapy in community-acquired pneumonia: a randomized trial. American journal of respiratory and critical care medicine. Jul 01 2006;174(1):84-93.

Cilloniz C, Ewig S, Polverino E, et al. Microbial aetiology of community-acquired pneumonia and its relation to severity. Thorax. Apr 2011;66(4):340-346.

Cilloniz C, Torres A. ePocrates online. Diseases page: Community-acquired pneumonia. https://online.epocrates.com. Last updated 3/30/2016. Accessed 5/25/2016

Craig A, Mai J, Cai S, Jeyaseelan S. Neutrophil Recruitment to the Lungs during Bacterial Pneumonia. Infection and Immunity. February 1, 2009;77(2):568-575.

Dallal RM, Harbrecht BG, Boujoukas AJ, Sirio CA, Farkas LM, Lee KK, Simmons RL. Fulminant Clostridium difficile: an underappreciated and increasing cause of death and complications. Annals of surgery. Mar 2002;235(3):363-372.

De Flora S, Grassi C, Carati L. Attenuation of influenza-like symptomatology and improvement of cell-mediated immunity with long-term N-acetylcysteine treatment. The European respiratory journal. Jul 1997;10(7):1535-1541.

de Roux A, Schmole-Thoma B, Siber GR, et al. Comparison of pneumococcal conjugate polysaccharide and free polysaccharide vaccines in elderly adults: conjugate vaccine elicits improved antibacterial immune responses and immunological memory. Clin Infect Dis. Apr 01 2008;46(7):1015-1023.

Dellit TH, Owens RC, McGowan JE, et al. Infectious Diseases Society of America and the Society for Healthcare Epidemiology of America Guidelines for Developing an Institutional Program to Enhance Antimicrobial Stewardship. Clinical Infectious Diseases. January 15, 2007;44(2):159-177.

Devaraj S, Leonard S, Traber MG, Jialal I. Gamma-tocopherol supplementation alone and in combination with alpha-tocopherol alters biomarkers of oxidative stress and inflammation in subjects with metabolic syndrome. Free radical biology & medicine. Mar 15 2008;44(6):1203-1208.

Di Pierro F, Rapacioli G, Ferrara T, Togni S. Use of a standardized extract from Echinacea angustifolia (Polinacea) for the prevention of respiratory tract infections. Alternative medicine review: a journal of clinical therapeutic. Mar 2012;17(1):36-41.

Dikasso D, Lemma H, Urga K, Debella A, Addis G, Tadele A, Yirsaw K. Investigation on the antibacterial properties of garlic (Allium sativum) on pneumonia causing bacteria. Ethiopian medical journal. Jul 2002;40(3):241-249.

Dogan M, Erol M, Cesur Y, Yuca SA, Dogan Z. The effect of 25-hydroxyvitamin D3 on the immune system. Journal of pediatric endocrinology & metabolism: JPEM. Oct 2009;22(10):929-935.

El Attar MM, Zaghloup MZ, Elmenoufr HS. Role of periodontitis in hospital-acquired pneumonia. Eastern Mediterranean health journal = La revue de sante de la Mediterranee orientale = al-Majallah al-sihhiyah li-sharq al-mutawassit. May 2010;16(5):563-569.

Emamian MH, Hassani AM, Fateh M. Respiratory Tract Infections and its Preventive Measures among Hajj Pilgrims, 2010: A Nested Case Control Study. International journal of preventive medicine. 2013;4(9):1030-1035.

Evans C. Malnutrition in the elderly: a multifactorial failure to thrive. The Permanente journal. Summer 2005;9(3):38-41.

Falcone M, Russo A, Cangemi R, et al. Lower mortality rate in elderly patients with community-onset pneumonia on treatment with aspirin. J Am Heart Assoc. Jan 06 2015;4(1):e001595.

Farazi A, Sofian M, Jabbariasl M, Nayebzadeh B. Coenzyme q10 administration in community-acquired pneumonia in the elderly. Iran Red Crescent Med J. Dec 2014;16(12):e18852.

Feldman C, Anderson R. Community-Acquired Pneumonia: Pathogenesis of Acute Cardiac Events and Potential Adjunctive Therapies. Chest. Aug 2015;148(2):523-532.

Fine MJ, Smith DN, Singer DE. Hospitalization decision in patients with community-acquired pneumonia: a prospective cohort study. The American journal of medicine. Dec 1990;89(6):713-721.

Gaillat J. [Community acquired pneumonia in the elderly]. La Revue du praticien. Sep 15 2003;53(13):1434-1441.

Goel V, Lovlin R, Chang C, et al. A proprietary extract from the echinacea plant (Echinacea purpurea) enhances systemic immune response during a common cold. Phytotherapy research: PTR. Aug 2005;19(8):689-694.

Gold DR, Litonjua AA, Carey VJ, et al. Lung VITAL: Rationale, design, and baseline characteristics of an ancillary study evaluating the effects of vitamin D and/or marine omega-3 fatty acid supplements on acute exacerbations of chronic respiratory disease, asthma control, pneumonia and lung function in adults. Contemporary clinical trials. Jan 16 2016;47:185-195.

Grijalva CG, Zhu Y, Williams DJ, et al. Association Between Hospitalization With Community-Acquired Laboratory-Confirmed Influenza Pneumonia and Prior Receipt of Influenza Vaccination. JAMA. Oct 13 2015;314(14):1488-1497.

Guyonnet S, Rolland Y. Screening for Malnutrition in Older People. Clin Geriatr Med. Aug 2015;31(3):429-437.

Hao Q, Dong BR, Wu T. Probiotics for preventing acute upper respiratory tract infections. The Cochrane database of systematic reviews. 2015;2:Cd006895.

He W, Fang T, Tu P. [Research progress on pharmacological activities of echinacoside]. Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica. Feb 2009;34(4):476-479.

Hemila H, Chalker E. Vitamin C for preventing and treating the common cold. The Cochrane database of systematic reviews. 2013;1:Cd000980.

Hemila H, Louhiala P. Vitamin C for preventing and treating pneumonia. The Cochrane database of systematic reviews. 2013;8:Cd005532.

Hicks LA, Chien YW, Taylor TH, Jr., Haber M, Klugman KP. Outpatient antibiotic prescribing and nonsusceptible Streptococcus pneumoniae in the United States, 1996-2003. Clin Infect Dis. Oct 2011;53(7):631-639.

Horita N, Otsuka T, Haranaga S, et al. Adjunctive Systemic Corticosteroids for Hospitalized Community-Acquired Pneumonia: Systematic Review and Meta-Analysis 2015 Update. Scientific Reports. 2015;5:14061.

Huang ST, Lin CL, Chang YJ, et al. Pneumococcal pneumonia infection is associated with end-stage renal disease in adult hospitalized patients. Kidney international. Nov 2014;86(5):1023-1030.

Hunt C, Chakravorty NK, Annan G, Habibzadeh N, Schorah CJ. The clinical effects of vitamin C supplementation in elderly hospitalised patients with acute respiratory infections. Int J Vitam Nutr Res. 1994;64(3):212-219.

Jain SK, Kanikarla-Marie, P, Warden P, Micinski D. L-cysteine supplementation upregulates glutathione (GSH) and vitamin D binding protein (VDBP) in hepatocytes cultured in high glucose and in vivo in liver, and increases blood levels of GSH, VDBP, and 25-hydroxy-vitamin D in Zucker diabetic fatty rats. Molecular Nutrition Food Research. 2016;60(5):1090-1098.

Jefferson T, Jones M, Doshi P, Spencer EA, Onakpoya I, Heneghan CJ. Oseltamivir for influenza in adults and children: systematic review of clinical study reports and summary of regulatory comments. BMJ (Clinical research ed.). 2014;348.

Johanesen PA, Mackin KE, Hutton ML, Awad MM, Larcombe S, Amy JM, Lyras D. Disruption of the Gut Microbiome: Clostridium difficile Infection and the Threat of Antibiotic Resistance. Genes. 2015;6(4):1347-1360.

Josling P. Preventing the common cold with a garlic supplement: a double-blind, placebo-controlled survey. Adv Ther. Jul-Aug 2001;18(4):189-193.

Jovanovich AJ, Ginde AA, Holmen J, Jablonski K, Allyn RL, Kendrick J, Chonchol M. Vitamin D level and risk of community-acquired pneumonia and sepsis. Nutrients. Jun 2014;6(6):2196-2205.

Kaysin A, Viera AJ. Community-Acquired Pneumonia in Adults: Diagnosis and Management. American family physician. 2016;94(9).

Kim HJ, Jang JG, Hong KS, Park JK, Choi EY. Relationship between serum vitamin D concentrations and clinical outcome of community-acquired pneumonia. The international journal of tuberculosis and lung disease: the official journal of the International Union against Tuberculosis and Lung Disease. Jun 2015;19(6):729-734.

King S, Glanville J, Sanders ME, Fitzgerald A, Varley D. Effectiveness of probiotics on the duration of illness in healthy children and adults who develop common acute respiratory infectious conditions: a systematic review and meta-analysis. The British journal of nutrition. Jul 14 2014;112(1):41-54.

Krone CL, van de Groep K, Trzcinski K, Sanders EA, Bogaert D. Immunosenescence and pneumococcal disease: an imbalance in host-pathogen interactions. The Lancet. Respiratory medicine. Feb 2014;2(2):141-153.

Kurihara S, Hiraoka T, Akutsu M, Sukegawa E, Bannai M, Shibahara S. Effects of (L)-cystine and (L)-theanine supplementation on the common cold: a randomized, double-blind, and placebo-controlled trial. Journal of amino acids. 2010;2010:307475.

Kwetkat A, Hagel S, Forstner C, Pletz MW. [Pneumococcal vaccination for prevention of pneumonia]. Zeitschrift fur Gerontologie und Geriatrie. Oct 2015;48(7):614-618.

Lambert AA, Lam JO, Paik JJ, Ugarte-Gil C, Drummond MB, Crowell TA. Risk of community-acquired pneumonia with outpatient proton-pump inhibitor therapy: a systematic review and meta-analysis. PloS one. 2015;10(6):e0128004.

Lee HJ, Ju J, Paul S, et al. Mixed tocopherols prevent mammary tumorigenesis by inhibiting estrogen action and activating PPAR-gamma. Clinical cancer research: an official journal of the American Association for Cancer Research. Jun 15 2009;15(12):4242-4249.

Lee MH, Arrecubieta C, Martin FJ, Prince A, Borczuk AC, Lowy FD. A postinfluenza model of Staphylococcus aureus pneumonia. The Journal of infectious diseases. Feb 15 2010;201(4):508-515.

Leow L, Simpson T, Cursons R, Karalus N, Hancox RJ. Vitamin D, innate immunity and outcomes in community acquired pneumonia. Respirology (Carlton, Vic.). May 2011;16(4):611-616.

Lin CF, Chang YH, Liu JC, Chuang MT, Chien LN. Statin use associated with a reduced risk of pneumonia requiring hospitalization in patients with myocardial infarction: a nested case-control study. BMC cardiovascular disorders. 2016;16(1):24.

Lin R. Crosstalk between Vitamin D Metabolism, VDR Signalling, and Innate Immunity. BioMed Research International. 2016;2016:1375858.

Lin ZB. Cellular and molecular mechanisms of immuno-modulation by Ganoderma lucidum. Journal of pharmacological sciences. Oct 2005;99(2):144-153.

Lindenmuth GF, Lindenmuth EB. The efficacy of echinacea compound herbal tea preparation on the severity and duration of upper respiratory and flu symptoms: a randomized, double-blind placebo-controlled study. Journal of alternative and complementary medicine (New York, N.Y.). Aug 2000;6(4):327-334.

Ling JX, Wei F, Li N, et al. Amelioration of influenza virus-induced reactive oxygen species formation by epigallocatechin gallate derived from green tea. Acta pharmacologica Sinica. Dec 2012;33(12):1533-1541.

Lipsitch M, Siber GR. How Can Vaccines Contribute to Solving the Antimicrobial Resistance Problem? mBio. 2016;7(3).

Liu KX, Zhu YG, Zhang J, Tao LL, Lee JW, Wang XD, Qu JM. Probiotics' effects on the incidence of nosocomial pneumonia in critically ill patients: a systematic review and meta-analysis. Crit Care. 2012;16(3):R109.

Loeb M. Pneumonia in Older Persons. Clinical Infectious Diseases. November 15, 2003 2003;37(10):1335-1339.

Mandell LA, Wunderink RG, Anzueto A, et al. Infectious Diseases Society of America/American Thoracic Society consensus guidelines on the management of community-acquired pneumonia in adults. Clin Infect Dis. Mar 1 2007;44 Suppl 2:S27-72.

Marrie TJ, Poulin-Costello M, Beecroft MD, Herman-Gnjidic Z. Etiology of community-acquired pneumonia treated in an ambulatory setting. Respiratory medicine. Jan 2005;99(1):60-65.

Marti C, Grosgurin O, Harbarth S, et al. Adjunctive Corticotherapy for Community Acquired Pneumonia: A Systematic Review and Meta-Analysis. PloS one. 2015;10(12):e0144032.

Mathur P, Ding Z, Saldeen T, Mehta JL. Tocopherols in the Prevention and Treatment of Atherosclerosis and Related Cardiovascular Disease. Clinical cardiology. Sep 2015;38(9):570-576.

Matsumoto K, Yamada H, Takuma N, Niino H, Sagesaka YM. Effects of green tea catechins and theanine on preventing influenza infection among healthcare workers: a randomized controlled trial. BMC complementary and alternative medicine. 2011;11:15.

Matsunaga K, Klein TW, Friedman H, Yamamoto Y. Epigallocatechin gallate, a potential immunomodulatory agent of tea components, diminishes cigarette smoke condensate-induced suppression of anti-Legionella pneumophila activity and cytokine responses of alveolar macrophages. Clinical and diagnostic laboratory immunology. Jul 2002;9(4):864-871.

Mayo Clinic. Diseases and Conditions: Pneumonia. http://www.mayoclinic.org/diseases-conditions/pneumonia/basics/definition/con-20020032?p=1. Last updated 03/14/2015. Accessed 01/10/2016.

Maziade PJ, Pereira P, Goldstein EJ. A Decade of Experience in Primary Prevention of Clostridium difficile Infection at a Community Hospital Using the Probiotic Combination Lactobacillus acidophilus CL1285, Lactobacillus casei LBC80R, and Lactobacillus rhamnosus CLR2 (Bio-K+). Clin Infect Dis. May 15 2015;60 Suppl 2:S144-147.

McCarty MF, DiNicolantonio JJ. An increased need for dietary cysteine in support of glutathione synthesis may underlie the increased risk for mortality associated with low protein intake in the elderly. Age (Dordrecht, Netherlands). Oct 2015;37(5):96.

McElhaney JE, Zhou X, Talbot HK, Soethout E, Bleackley RC, Granville DJ, Pawelec G. The unmet need in the elderly: how immunosenescence, CMV infection, co-morbidities and frailty are a challenge for the development of more effective influenza vaccines. Vaccine. Mar 9 2012;30(12):2060-2067.

Meydani SN, Barnett JB, Dallal GE, Fine BC, Jacques PF, Leka LS, Hamer DH. Serum zinc and pneumonia in nursing home elderly. The American journal of clinical nutrition. Oct 2007;86(4):1167-1173.

Meydani SN, Han SN, Hamer DH. Vitamin E and respiratory infection in the elderly. Annals of the New York Academy of Sciences. Dec 2004;1031:214-222.

Miyagawa K, Hayashi Y, Kurihara S, Maeda A. Co-administration of l-cystine and l-theanine enhances efficacy of influenza vaccination in elderly persons: nutritional status-dependent immunogenicity. Geriatrics & gerontology international. Dec 2008;8(4):243-250.

Molinos L, Zalacain R, Menendez R, et al. Sensitivity, Specificity, and Positivity Predictors of the Pneumococcal Urinary Antigen Test in Community-Acquired Pneumonia. Annals of the American Thoracic Society. Oct 2015;12(10):1482-1489.

Montassier E, Goffinet N, Potel G, Batard E. How to reduce antibiotic consumption for community-acquired pneumonia? Medecine et maladies infectieuses. Feb 2013;43(2):52-59.

Murray MA, Chotirmall SH. The Impact of Immunosenescence on Pulmonary Disease. Mediators Inflamm. 2015;2015:692546.

Musher DM, Goldman L (ed.), Schafer AI (ed.). Goldman's Cecil Medicine, Twenty-Fourth Edition. Chapter 97: Overview of Pneumonia; 610-620.e2. Copyright 2012 Saunders, an imprint of Elsevier, Inc. www.clinicalkey.com. Accessed: 3/19/2015

Nantz MP, Rowe CA, Muller CE, Creasy RA, Stanilka JM, Percival SS. Supplementation with aged garlic extract improves both NK and gammadelta-T cell function and reduces the severity of cold and flu symptoms: a randomized, double-blind, placebo-controlled nutrition intervention. Clinical nutrition (Edinburgh, Scotland). Jun 2012;31(3):337-344.

Nassaji M, Ghorbani R, Afshar RK. The Effect of Statins Use on the Risk and Outcome of Acute Bacterial Infections in Adult Patients. Journal of clinical and diagnostic research: JCDR. Nov 2015;9(11):OC09-OC12.

Neupane B, Walter SD, Krueger P, Marrie T, Loeb M. Predictors of inhospital mortality and re-hospitalization in older adults with community-acquired pneumonia: a prospective cohort study. BMC geriatrics. 2010;10:22.

NFID. National Foundation for Infectious Diseases. Facts About Pneumococcal Disease for Adults. http://www.adultvaccination.org/vpd/pneumococcal/facts.html?css=print. Last updated 10/2014. Accessed 01/28/2016.

NLM. U. S. National Library of Medicine. MedlinePLus: Medical Encyclopedia: Exercise and immunity. Available at https://www.nlm.nih.gov/medlineplus/ency/article/007165.htm. Last updated 05/11/2014. Accessed 02/04/2016.

NLM. U. S. National Library of Medicine. PubMed Health. Pneumonia. http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0063028/. Last updated 6/10/2016a. Accessed 6/10/2016.

NLM. U.S. National Library of Medicine. Pneumonia - weakened immune system. https://www.nlm.nih.gov/medlineplus/ency/article/000093.htm. Last updated 6/7/2016b. Accessed 6/28/2016.

Oh SF, Vickery TW, Serhan CN. Chiral lipidomics of E-series resolvins: aspirin and the biosynthesis of novel mediators. Biochimica et biophysica acta. Nov 2011;1811(11):737-747.

Ortega R, Hansen CJ, Elterman K, Woo A. Pulse Oximetry. New England Journal of Medicine. 2011;364(16):e33.

Oz F, Gul S, Kaya MG, et al. Does aspirin use prevent acute coronary syndrome in patients with pneumonia: multicenter prospective randomized trial. Coronary artery disease. May 2013;24(3):231-237.

Paju S, Scannapieco FA. Oral biofilms, periodontitis, and pulmonary infections. Oral diseases. Nov 2007;13(6):508-512.

Park M, Yamada H, Matsushita K, et al. Green tea consumption is inversely associated with the incidence of influenza infection among schoolchildren in a tea plantation area of Japan. The Journal of nutrition. Oct 2011;141(10):1862-1870.

Park S, Johnson M, Fischer JG. Vitamin and mineral supplements: barriers and challenges for older adults. Journal of nutrition for the elderly. 2008;27(3-4):297-317.

Patel S, Goyal A. Recent developments in mushrooms as anti-cancer therapeutics: a review. 3 Biotech. Mar 2012;2(1):1-15.

Peh HY, Tan WS, Liao W, Wong WS. Vitamin E therapy beyond cancer: Tocopherol versus tocotrienol. Pharmacology & therapeutics. Jun 2016;162:152-169.

Percival SS. Aged Garlic Extract Modifies Human Immunity. The Journal of nutrition. Feb 2016;146(2):433s-436s.

Petrof EO, Dhaliwal R, Manzanares W, Johnstone J, Cook D, Heyland DK. Probiotics in the critically ill: a systematic review of the randomized trial evidence. Critical care medicine. Dec 2012;40(12):3290-3302.

Pinzone MR, Cacopardo B, Abbo L, Nunnari G. Duration of antimicrobial therapy in community acquired pneumonia: less is more. TheScientificWorldJournal. 2014;2014:759138.

Prasad AS, Beck FW, Bao B, Fitzgerald JT, Snell DC, Steinberg JD, Cardozo LJ. Zinc supplementation decreases incidence of infections in the elderly: effect of zinc on generation of cytokines and oxidative stress. The American journal of clinical nutrition. Mar 2007;85(3):837-844.

Prasad AS, Beck FW, Bao B, Snell D, Fitzgerald JT. Duration and severity of symptoms and levels of plasma interleukin-1 receptor antagonist, soluble tumor necrosis factor receptor, and adhesion molecules in patients with common cold treated with zinc acetate. J Infect Dis. Mar 15 2008;197(6):795-802.

Prasad AS, Fitzgerald JT, Bao B, Beck FW, Chandrasekar PH. Duration of symptoms and plasma cytokine levels in patients with the common cold treated with zinc acetate. A randomized, double-blind, placebo-controlled trial. Ann Intern Med. Aug 15 2000;133(4):245-252.

Pregliasco F, Anselmi G, Fonte L, Giussani F, Schieppati S, Soletti L. A new chance of preventing winter diseases by the administration of synbiotic formulations. Journal of clinical gastroenterology. Sep 2008;42 Suppl 3 Pt 2:S224-233.

Quraishi SA, Bittner EA, Christopher KB, Camargo CA, Jr. Vitamin D status and community-acquired pneumonia: results from the third National Health and Nutrition Examination Survey. PloS one. 2013;8(11):e81120.

Raghavendran K, Mylotte JM, Scannapieco FA. Nursing home-associated pneumonia, hospital-acquired pneumonia and ventilator-associated pneumonia: the contribution of dental biofilms and periodontal inflammation. Periodontology 2000. 2007;44:164-177.

Raus K, Pleschka S, Klein P, Schoop R, Fisher P. Effect of an Echinacea-Based Hot Drink Versus Oseltamivir in Influenza Treatment: A Randomized, Double-Blind, Double-Dummy, Multicenter, Noninferiority Clinical Trial. Current therapeutic research, clinical and experimental. Dec 2015;77:66-72.

Ren S, Newby D, Li SC, Walkom E, Miller P, Hure A, Attia J. Effect of the adult pneumococcal polysaccharide vaccine on cardiovascular disease: a systematic review and meta-analysis. Open Heart. 2015;2(1):e000247.

Restrepo MI, Mortensen EM, Velez JA, Frei C, Anzueto A. A comparative study of community-acquired pneumonia patients admitted to the ward and the ICU. Chest. Mar 2008;133(3):610-617.

Riddle DJ, Dubberke ER. Clostridium difficile infection in the intensive care unit. Infectious disease clinics of North America. Sep 2009;23(3):727-743.

Ridenhour BJ, Campitelli MA, Kwong JC, et al. Effectiveness of inactivated influenza vaccines in preventing influenza-associated deaths and hospitalizations among Ontario residents aged >/= 65 years: estimates with generalized linear models accounting for healthy vaccinee effects. PloS one. 2013;8(10):e76318.

Roca I, Akova M, Baquero F, et al. The global threat of antimicrobial resistance: science for intervention. New microbes and new infections. Jul 2015;6:22-29.

Roxas M, Jurenka J. Colds and influenza: a review of diagnosis and conventional, botanical, and nutritional considerations. Alternative medicine review: a journal of clinical therapeutic. Mar 2007;12(1):25-48.

Rubinstein E, Keynan Y. Short-course therapy for severe infections. International journal of antimicrobial agents. Jun 2013;42 Suppl:S22-24.

Saeterdal I, Underland V, Nilsen ES. The effect of probiotics for preventing acute upper respiratory tract infections. Glob Adv Health Med. May 2012;1(2):124-125.

Satomura K, Kitamura T, Kawamura T, et al. Prevention of upper respiratory tract infections by gargling: a randomized trial. Am J Prev Med. Nov 2005;29(4):302-307.

Schapowal A, Klein P, Johnston SL. Echinacea reduces the risk of recurrent respiratory tract infections and complications: a meta-analysis of randomized controlled trials. Adv Ther. Mar 2015;32(3):187-200.

Schuetz P, Muller B, Christ-Crain M, et al. Procalcitonin to initiate or discontinue antibiotics in acute respiratory tract infections. The Cochrane database of systematic reviews. Sep 12 2012(9):Cd007498.

Senchina DS, Kohut ML. Immunological outcomes of exercise in older adults. Clin Interv Aging. 2007;2(1):3-16.

Serhan CN, Arita M, Hong S, Gotlinger K. Resolvins, docosatrienes, and neuroprotectins, novel omega-3-derived mediators, and their endogenous aspirin-triggered epimers. Lipids. Nov 2004;39(11):1125-1132.

Sethi S. Merck Manual: Professional Version. Community-Acquired Pneumonia. http://www.merckmanuals.com/professional/pulmonary-disorders/pneumonia/community-acquired-pneumonia. Last updated 12/2014. Accessed 1/9/2017.

Siemieniuk RA, Meade MO, Alonso-Coello P, et al. Corticosteroid Therapy for Patients Hospitalized With Community-Acquired Pneumonia: A Systematic Review and Meta-analysis. Ann Intern Med. Oct 6 2015;163(7):519-528.

Simonetti AF, Viasus D, Garcia-Vidal C, Carratala J. Management of community-acquired pneumonia in older adults. Therapeutic advances in infectious disease. Feb 2014;2(1):3-16.

Simpson CR, Lone N, Kavanagh K, Ritchie LD, Robertson C, Sheikh A, McMenamin J. Health Services and Delivery Research. Seasonal Influenza Vaccine Effectiveness (SIVE): an observational retrospective cohort study - exploitation of a unique community-based national-linked database to determine the effectiveness of the seasonal trivalent influenza vaccine. Southampton (UK): NIHR Journals Library. 11/2013.

Simpson RJ, Guy K. Coupling aging immunity with a sedentary lifestyle: has the damage already been done?--a mini-review. Gerontology. 2010;56(5):449-458.

Sinclair A, Xie X, Teltscher M, Dendukuri N. Systematic review and meta-analysis of a urine-based pneumococcal antigen test for diagnosis of community-acquired pneumonia caused by Streptococcus pneumoniae. J Clin Microbiol. Jul 2013;51(7):2303-2310.

Soboleva AV, Krasnoshtanova AA, Krylov IA. Conversion of L-Cystine and L-Cysteine to Taurine by the Enzyme Systems of the Liver Cells. Applied Biochemistry and Microbiology. 2004;40(3):236-240.

Song JY, Lee JS, Wie SH, et al. Prospective cohort study on the effectiveness of influenza and pneumococcal vaccines in preventing pneumonia development and hospitalization. Clinical and vaccine immunology: CVI. Feb 2015;22(2):229-234.

Stechmiller JK. Early nutritional screening of older adults: review of nutritional support. Journal of infusion nursing: the official publication of the Infusion Nurses Society. May-Jun 2003;26(3):170-177.

Strand TA, Briles DE, Gjessing HK, Maage A, Bhan MK, Sommerfelt H. Pneumococcal pulmonary infection, septicaemia and survival in young zinc-depleted mice. The British journal of nutrition. Aug 2001;86(2):301-306.

Suarez-Arroyo IJ, Rosario-Acevedo R, Aguilar-Perez A, et al. Anti-tumor effects of Ganoderma lucidum (reishi) in inflammatory breast cancer in in vivo and in vitro models. PloS one. 2013;8(2):e57431.

Sura L, Madhavan A, Carnaby G, Crary MA. Dysphagia in the elderly: management and nutritional considerations. Clin Interv Aging. 2012;7:287-298.

Taylor PW, Hamilton-Miller JMT, Stapleton PD. Antimicrobial properties of green tea catechins. Food science and technology bulletin. 2005;2:71-81.

Tedja R, Gordon S. Cleveland Clinic Center for Continuing Education [online]. Disease Management. Hospital-Acquired, Health Care-Associated, and Ventilator-Associated Pneumonia. http://www.clevelandclinicmeded.com/medicalpubs/diseasemanagement/infectious-disease/health-care-associated-pneumonia/. 11/2013. Accessed 6/22/2016.

Terblanche M, Almog Y, Rosenson RS, Smith TS, Hackam DG. Statins and sepsis: multiple modifications at multiple levels. Lancet Infect Dis. May 2007;7(5):358-368.

Thornsberry C, Brown NP, Draghi DC, Evangelista AT, Yee YC, Sahm DF. Antimicrobial activity among multidrug-resistant Streptococcus pneumoniae isolated in the United States, 2001-2005. Postgrad Med. Sep 2008;120(3 Suppl 1):32-38.

Tirouvanziam R, Conrad CK, Bottiglieri T, Herzenberg LA, Moss RB, Herzenberg LA. High-dose oral N-acetylcysteine, a glutathione prodrug, modulates inflammation in cystic fibrosis. Proceedings of the National Academy of Sciences of the United States of America. Mar 21 2006;103(12):4628-4633.

Torres A. First Consult: Community acquired pneumonia in adults. www.clinicalkey.com. Copyright Elsevier BV, Inc. Last updated 12/12/2013. Accessed 12/10/2015.

Torres A, Peetermans WE, Viegi G, Blasi F. Risk factors for community-acquired pneumonia in adults in Europe: a literature review. Thorax. Nov 2013;68(11):1057-1065.

Troeman DP, Postma DF, van Werkhoven CH, Oosterheert JJ. The immunomodulatory effects of statins in community-acquired pneumonia: a systematic review. The Journal of infection. Aug 2013;67(2):93-101.

Tsai CC, Yang FL, Huang ZY, et al. Oligosaccharide and peptidoglycan of Ganoderma lucidum activate the immune response in human mononuclear cells. Journal of agricultural and food chemistry. Mar 21 2012;60(11):2830-2837.

UMMC. University of Maryland Medical Center. Health Information: Medical Reference Guide: Pneumonia. Available at https://umm.edu/health/medical/reports/articles/pneumonia. Last updated 04/26/2012. Accessed 01/18/2016.

Urben LM, Wiedmar J, Boettcher E, Cavallazzi R, Martindale RG, McClave SA. Bugs or drugs: are probiotics safe for use in the critically ill? Current gastroenterology reports. 2014;16(7):388.

van der Sluijs KF, van der Poll T, Lutter R, Juffermans NP, Schultz MJ. Bench-to-bedside review: bacterial pneumonia with influenza - pathogenesis and clinical implications. Critical care (London, England). 2010;14(2):219.

van Werkhoven CH, Huijts SM, Bolkenbaas M, Grobbee DE, Bonten MJ. The Impact of Age on the Efficacy of 13-valent Pneumococcal Conjugate Vaccine in Elderly. Clin Infect Dis. Dec 15 2015;61(12):1835-1838.

van Zandwijk N. N-acetylcysteine (NAC) and glutathione (GSH): antioxidant and chemopreventive properties, with special reference to lung cancer. Journal of cellular biochemistry. Supplement. 1995;22:24-32.

Wachtel-Galor S, Yuen J, Buswell JA, Benzie IFF. Ganoderma lucidum (Lingzhi or Reishi): A Medicinal Mushroom. In: Benzie IFF, Wachtel-Galor S, eds. Herbal Medicine: Biomolecular and Clinical Aspects. Boca Raton (FL): CRC Press/Taylor & Francis Llc.; 2011.

Watanabe I, Kuriyama S, Kakizaki M, et al. Green tea and death from pneumonia in Japan: the Ohsaki cohort study. The American journal of clinical nutrition. Sep 2009;90(3):672-679.

Wootton DG, Diggle PJ, Court J, et al. Recovery from pneumonia requires efferocytosis which is impaired in smokers and those with low body mass index and enhanced by statins. Thorax. Nov 2016;71(11):1052-1054.

Wu JH, Ward NC, Indrawan AP, et al. Effects of alpha-tocopherol and mixed tocopherol supplementation on markers of oxidative stress and inflammation in type 2 diabetes. Clin Chem. Mar 2007;53(3):511-519.

Wu XM, Gao XM, Tsim KW, Tu PF. An arabinogalactan isolated from the stems of Cistanche deserticola induces the proliferation of cultured lymphocytes. International journal of biological macromolecules. Dec 30 2005;37(5):278-282.

Xuan GD, Liu CQ. [Research on the effect of phenylethanoid glycosides (PEG) of the Cistanche deserticola on anti-aging in aged mice induced by D-galactose]. Zhong yao cai = Zhongyaocai = Journal of Chinese medicinal materials. Sep 2008;31(9):1385-1388.

Yamada H, Takuma N, Daimon T, Hara Y. Gargling with tea catechin extracts for the prevention of influenza infection in elderly nursing home residents: a prospective clinical study. Journal of alternative and complementary medicine (New York, N.Y.). Sep 2006;12(7):669-672.

Yamada P, Iijima R, Han J, Shigemori H, Yokota S, Isoda H. Inhibitory effect of acteoside isolated from Cistanche tubulosa on chemical mediator release and inflammatory cytokine production by RBL-2H3 and KU812 cells. Planta medica. Oct 2010;76(14):1512-1518.

Yamamoto Y, Matsunaga K, Friedman H. Protective effects of green tea catechins on alveolar macrophages against bacterial infections. Biofactors. 2004;21(1-4):119-121.

Youssef DA, Ranasinghe T, Grant WB, Peiris AN. Vitamin D's potential to reduce the risk of hospital-acquired infections. Dermatoendocrinol. Apr 1 2012;4(2):167-175.

Zhai Z, Liu Y, Wu L, et al. Enhancement of innate and adaptive immune functions by multiple Echinacea species. Journal of medicinal food. Sep 2007;10(3):423-434.

Zhang HQ, Zhang AX. [Effects of Cistanche deserticola on immune function in mice]. Zhong xi yi jie he za zhi = Chinese journal of modern developments in traditional medicine/Zhongguo Zhong xi yi jie he yan jiu hui (chou), Zhong yi yan jiu yuan, zhu ban. Dec 1988;8(12):736-737, 710.

Zhang K, Ma X, He W, et al. Extracts of Cistanche deserticola Can Antagonize Immunosenescence and Extend Life Span in Senescence-Accelerated Mouse Prone 8 (SAM-P8) Mice. Evidence-based complementary and alternative medicine: eCAM. 2014;2014:601383.

Zhang L, Shao WF, Yuan LF, Tu PF, Ma ZZ. Decreasing pro-inflammatory cytokine and reversing the immunosenescence with extracts of Pu-erh tea in senescence accelerated mouse (SAM). Food Chem. Dec 15 2012;135(4):2222-2228.

Zhu XL, Lin ZB. Effects of Ganoderma lucidum polysaccharides on proliferation and cytotoxicity of cytokine-induced killer cells. Acta pharmacologica Sinica. Sep 2005;26(9):1130-1137.