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Probiotic Blend Reduces Cold and Flu

Clinical research has shown that a combination of probiotics plus a prebiotic reduces the number of flulike illnesses by 75% and colds by 39%.

Scientifically reviewed by: Dr. Gary Gonzalez, MD, on December 2020. Written By Michael Downey.

Catching a cold or the flu is more than a nuisance. It can be deadly.

Up to 62,000 Americans died from influenza during the 2019-2020 flu season, according to preliminary data from the U.S. Centers for Disease Control and Prevention.1

About 70%-85% of seasonal-flu-related deaths occur in people 65 years of age and older.2

Though the common cold is less serious, it can develop into pneumonia, especially in those with weakened immune systems.3

A clinical study has demonstrated that a specific combination of probiotics and a prebiotic can reduce incidence of both flu and colds.

In this human study, the number of flu and flu-like illnesses decreased by 75% while colds decreased by 39%.

And when flu or colds did develop, duration and severity were reduced.4

This novel probiotic defense can provide critical immune support during the winter season.

Common Cold and Flu

X-ray of lungs showing effected areas in red

A viral infection of the upper respiratory tract, the common cold, is the leading cause of missed days at work or school. Treatment is generally aimed at managing symptoms.

The flu is a more serious respiratory infection that may progress to pneumonia, especially in older people or people with suppressed immune systems.

Those aged 65 and older and with certain medical conditions (heart disease, diabetes, or asthma), children, and pregnant women, are at a higher risk for flu complications.

Probiotics Block Respiratory Infections

Colds and flu are generally treated with medications that reduce the symptoms but do nothing to promote immunity or help fend off invading viruses.

Scientists have found that probiotics can reduce the risk of developing colds and flu in the first place.

Specific strains of probiotics help rebalance the gut flora to bolster immune defenses against the flu and the common cold, while reducing risk of other upper respiratory tract infections.4-6

In those who do get sick, these probiotics were shown to reduce the severity and duration of the illness.

Helping Probiotics Thrive

Woman holding her sinuses in pain

To fully thrive, probiotics need prebiotics. These are nutrients that the probiotics can digest, supporting their survival and growth.

A blend of probiotics and a prebiotic can help the probiotics to flourish and work optimally.

One of the classes of prebiotics is called galacto-oligosaccharides, which are plant sugars that pass undigested. They remain in the colon to feed and promote the growth of beneficial gut microbes.

Results of Human Trials

Several small studies have shown that probiotics reduce the number of upper respiratory tract infections, as well as the average length of illness, need for antibiotics, and work absences.7-9

Based on these findings, scientists set out to test the effectiveness of a blend of five probiotics in fighting colds and flu.

The probiotics are:

  • B. lactis BS01,
  • L. plantarum LP01,
  • L. plantarum LP02,
  • L. rhamnosus LR04, and
  • L. rhamnosus LR05.

These five probiotic strains were combined with galactooligosaccharides, a prebiotic, to further enhance effectiveness.

In a randomized, double-blind study, 250 healthy adult volunteers received either the probiotic-prebiotic blend or a placebo daily for 90 days during flu season.4

In those who took the probiotic-prebiotic blend, the number of flu and flu-like respiratory illnesses was reduced by 75%,4 and the number of colds was reduced by 39%.4

Even in those who did develop an illness, the probiotic-prebiotic combination led to:4

  • A 37% reduction in the severity of flu symptoms,
  • A 19% reduction in the severity of cold symptoms,
  • An average one-day reduction in the duration of colds,
  • About a three-day reduction in the duration of coughs, and
  • Close to a 1.5-day reduction in the duration of all acute respiratory tract infections.

These five probiotic strains, supported by an effective prebiotic, enhance the body’s immune defenses against colds, flu, and other respiratory illnesses.

What you need to know

Warding Off Colds and Flu

  • The common cold is the leading cause of medical visits and missed days at work or school.
  • The flu and other upper respiratory tract infections pose considerable dangers for older adults, who can develop serious complications.
  • Probiotics help defend against infection by supporting a healthy immune system.
  • A blend of five specific probiotics and a prebiotic has been shown in a double-blind, human trial to significantly reduce the number of flu cases, colds, and similar illnesses.
  • In those who did become ill, this blend reduced the duration and severity of flu, cold, and other upper respiratory tract infections.


Woman sitting up at a desk working and smiling

The flu kills tens of thousands of Americans each year, and colds cause weeks of misery.

Older people are particularly susceptible because they have a lower level of immunity.

Scientists have developed a specially designed blend of five strains of probiotics that, along with a potent prebiotic to support their survival, can dramatically reduce the incidence of flu, colds, and other upper respiratory tract infections.

The purpose is to duplicate research showing robust, reduced incidences of flu, colds, and other upper respiratory tract infections.

In addition, when illnesses did occur, those taking this probiotic-prebiotic blend experienced reduced severity and duration.

If you have any questions on the scientific content of this article, please call a Life Extension® Wellness Specialist at 1-866-864-3027.


  1. Available at: Accessed October 15, 2020.
  2. Available at: Accessed October 15, 2020.
  3. Available at: Accessed October 15, 2020.
  4. Pregliasco F, Anselmi G, Fonte L, et al. A new chance of preventing winter diseases by the administration of synbiotic formulations. J Clin Gastroenterol. 2008 Sep;42 Suppl 3 Pt 2:S224-33.
  5. Lefevre M, Racedo SM, Ripert G, et al. Probiotic strain Bacillus subtilis CU1 stimulates immune system of elderly during common infectious disease period: a randomized, double-blind placebo-controlled study. Immun Ageing. 2015;12(1):24.
  6. Belcaro G, Cesarone MR, Cornelli U, et al. Prevention of flu episodes with colostrum and Bifivir compared with vaccination: an epidemiological, registry study. Panminerva Med. 2010 Dec;52(4):269-75.
  7. Hao Q, Dong BR, Wu T. Probiotics for preventing acute upper respiratory tract infections. Cochrane Database Syst Rev. 2015 Feb 3(2):CD006895.
  8. King S, Glanville J, Sanders ME, et al. 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. Br J Nutr. 2014 Jul 14;112(1):41-54.
  9. Lehtoranta L, Pitkaranta A, Korpela R. Probiotics in respiratory virus infections. Eur J Clin Microbiol Infect Dis. 2014 Aug;33(8):1289-302.
  10. Lei WT, Shih PC, Liu SJ, et al. Effect of Probiotics and Prebiotics on Immune Response to Influenza Vaccination in Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Nutrients. 2017 Oct 27;9(11):1175.