Life Extension Magazine®
Woman in dentist office for cleaning of oral bacteria

Issue: Dec 2018

Link Between Gum Disease and Aging

Two oral probiotics boost gum health by rebalancing the oral microbiome to reduce plaque and bleeding gums.

By Michael Downey, Health & Wellness Author.

In spite of the best intentions to perform daily brushing and flossing, many people still end up with periodontal disease, often referred to as "gum disease." The result can be deterioration of the gum and tooth loss.1

Periodontal disease doesn't just stay in the mouth. It can spread pathogens throughout the body, resulting in more serious diseases.2-10

When the oral microbiome becomes unbalanced, it results in a weakened immune system of the oral cavity. This opens the door to gum disease caused by excessive growth of pathogenic oral bacteria. Gum disease further weakens our overall immune system.

Two unique oral probiotics have been identified that specifically target and improve gum health. In addition, they restore a healthy balance to the oral microbiome.

Clinical evidence demonstrated that these two probiotics can lead to a reduction in indicators of plaque buildup, gingivitis, bleeding gums, and pocket depth between gums and tooth roots.11,12

Improving gum health by taking these probiotics in lozenge form may lower the risk for a host of inflammatory diseases commonly associated with aging.

What you need to know

  • Cardiovascular, brain, kidney, and bone diseases and cancer are just some of the disorders that can occur as a result of periodontal (gum) disease.
  • An unbalanced oral microbiome is critically involved in the development of periodontal disease.
  • The bacterial strain S. salivarius M18 has been documented to rebalance the bacterial populations of the mouth, inhibiting poor oral health.
  • Scientists have also shown that a heat-treated form of the bacterial strain L. plantarum L-137 boosts oral immune function, reducing inflammation and promoting healing.
  • These two probiotics, when taken as a daily lozenge, can work together to protect oral health and also promise whole-body benefits.

Oral Bacteria Threaten Whole-Body Health

Oral Bacteria Threaten Whole-Body Health  

Nearly half of all Americans over age 30 have periodontal disease,13 which is associated with disorders throughout the body,14 including cardiovascular, lung, kidney, bone, and Alzheimer's diseases.5-10,15-23

Recent research has found that the mouth is "a potential reservoir for bacteria that can promote intestinal disease..."2,12

Periodontal disease afflicts over 70% of those aged 65 or over.13

Unhealthy teeth and gums can lead to disorders in virtually every part of the body. An underlying link is periodontal disease's effect on the oral microbiome, the natural community of microbes living in the oral cavity.

When healthy, the oral microbiome supports and protects the delicate mucous membranes as well as the surface of the teeth themselves.

However, inadequate oral hygiene, as well as poor diet and lifestyle factors, drugs, and disease, can disrupt this delicate microbiome balance. The resulting microbial imbalance—often called dysbiosis—allows excessive growth of pathogenic (disease-causing) organisms in the oral cavity.

This in turn wreaks havoc on the normal immune system and creates a vicious cycle that can have disastrous effects on many body systems,24 causing diseases in parts of the body far removed from the mouth itself.25

To prevent these far-reaching effects, scientists conducted extensive research on probiotics, eventually identifying two strains of bacteria that can halt this process on two fronts:11,26,27

  • Streptococcus salivarius M18, which kills harmful oral bacteria and goes on to help rebalance the oral microbiome, and

  • Lactobacillus plantarum L-137, which boosts oral immune function and promotes healing.

The results are extremely promising. Let's review the studies validating the striking benefits of these strains.

Periodontal Disease

While some bacteria protect our teeth and gums, other bacteria and microorganisms cause tooth decay and periodontal (gum) disease. They break down compounds from food called fermentable carbohydrates, producing byproducts such as lactic acid and other organic acids that promote enamel and dentin demineralization. This softening of the enamel then leads to the development of dental caries, or cavities.

Under certain conditions, harmful bacteria excrete a substance similar to glue that helps form a biofilm, commonly called plaque. This plaque is a living aggregation of various bacteria and fungi that attaches itself to the enamel surface of the tooth. Biofilm is at the root of dental disease.

Over time, plaque hardens and takes on various minerals, at which point it is called tartar. This is the hard coating that dental hygienists work to scrape off your teeth.

Gingivitis occurs when dental plaque stimulates an immune response in the soft tissues surrounding the teeth, causing the gums to become inflamed, irritated, swollen, red, and often easily bleeding. Acting on the immune system, it increases inflammatory factors and reduces anti-inflammatory factors. Left untreated, gingivitis can progress to periodontitis, a condition in which certain bacteria destroy the supportive structures of the teeth, which may ultimately lead to tooth loss.

Worse, new science is showing that periodontal disease has far-reaching consequences that extend into most body systems, largely the result of inflammatory changes and other signaling pathway disruptions throughout the body. Gum disease is now associated with disorders of the brain, heart, lungs, kidney, liver, bone, and blood vessels—any of which may promote aging and shorten lifespan.5,7,19-23

Brushing mechanically breaks up the biofilm to some extent, and along with rinsing and flossing, helps to remove fermentable carbohydrates. However, there is more that can be done to fight what is, essentially, a bacterial enemy.

The good news is that rebalancing the oral microbiome can reduce bacteria-laden plaque, resulting in significant reductions in whole-body inflammation. This means that improving our tooth and gum health is vital not just for those oral structures, but also for the preservation of our health in practically all body systems.

Together, the two beneficial probiotic strains described in this article have been demonstrated to rebalance the oral microbiome and enhance oral immunity. Scientists have shown that this in turn inhibits periodontal disease and protects total-body health.

S. Salivarius M18


Scientists found that Streptococcus salivarius M18 helps create a healthier oral environment, providing a simple strategy that could help prevent disease throughout the body by several mechanisms. Studies showed that this novel bacterium:

  • Specifically colonizes the human mouth, resulting in reproducing colonies of this beneficial organism even after supplementation ends,26,27

  • Competes with harmful oral bacteria, thus supporting healthy teeth and gums,27

  • Generates abundant numbers of bacteria-suppressing weapons called bacteriocins, which function like antibiotics at the local level,28-30 to inhibit tooth and gum disease–producing organisms,26,29-31

  • Produces enzymes (dextranase and urease) that help break down dental plaque, a main cause of tooth decay and gum disease,26

  • Helps to generate a neutral oral pH, which helps balance the oral microbiome and cut disease risk,26 and

  • Reduces the presence of pro-inflammatory cytokines (IL-6), breaking the infection-inflammation-infection cycle that accelerates gum disease and threatens the whole body.26

To validate the effects of this strain on humans, scientists conducted several clinical studies. In one of these trials, they showed that 88% of S. salivarius M18 recipients maintained plaque scores lower than their pretreatment values at the end of a three-month treatment period, compared with just 44% of placebo recipients.26

Then, investigators set up a randomized, controlled trial to determine the impact of S. salivarius M18 treatment on some of the most important clinical parameters of oral and gingival (gum) health.12

They recruited men and women, aged 20–60 years, with moderate or severe gingivitis (gingival index score of 2 or 3) and moderate periodontitis (less than 6 mm probing pocket depth). For 30 days, half received no treatment, and half took lozenges of 200 million S. salivarius M18 daily, after brushing. The lozenge group was observed for an additional 30 days after treatment to measure any lasting effect. There were dramatic improvements in the S. salivarius M18 group.12

Compared to control, on day 30—the last day of active treatment—they found:12

  • 44% lower mean plaque index scores,
  • 42% lower mean gingival index scores,
  • 53% lower modified sulcus bleeding index scores, and
  • 20% lower probing pocket depth measurements.

And, on day 60—a full 30 days after active treatment had stopped—they observed:12

  • 37% lower mean plaque index scores,
  • 35% lower mean gingival index scores,
  • 51% lower modified sulcus bleeding index scores, and
  • 22% lower probing pocket depth measurements.

Even the lowest scores for each index in the S. salivarius M18 group indicated a return to near-normal values, while the scores remained markedly abnormal in control subjects.12

This study demonstrated the ability of the probiotic lozenge not only to significantly improve all four parameters of periodontal health, but also to sustain these benefits long after the supplementation period ended. A critical factor in this lasting effect is the capacity of S. salivarius M18 to colonize the oral cavity.

Whereas S. salivarius M18 improved gum-health by colonizing the mouth, that by itself is not enough to ensure optimal oral health. It is also essential to support the body's natural immune defenses against gum disease. That's where the second probiotic strain comes in.

Lactobacillus Plantarum Strain L-137

Dental X-rays  

Scientists were able to demonstrate that, when heat-treated, the bacterium known as Lactobacillus plantarum strain L-137 can reverse infection-caused reductions in the oral immune system's fighting ability.11

When the oral microbiome gets out of whack, this weakens the immune system of the mouth and gums, leaving us vulnerable to infections by bacteria that cause gum disease which further weaken the immune system, such as the bacterium Porphyromonas gingivalis, abbreviated as P. gingivalis.

P. gingivalis disrupts important immune factors known as interleukins. It downregulates protective interleukins called IL-12 and upregulates pro-inflammatory interleukins called IL-6. This creates a disease-promoting cycle that makes it nearly impossible for the body to heal itself.32-34

To make matters worse, natural IL-12 production decreases with aging, leaving a deficit in immune responses in the mouth.35 This allows organisms such as P. gingivalis to evade the immune system and become overgrown, ultimately causing gum disease.36

Searching for a way to block this spiral and boost local immune function, scientists finally demonstrated that, when killed by heat treatment, the bacterium L. plantarum strain L-137 increases production of the protective IL-12.11

Treating periodontitis patients with this immune-boosting bacterium aids in restoring the mouth's natural, oral immune response, helping to heal diseased, inflamed gums. This treatment also helps prevent an array of diseases throughout the body that are strongly associated with periodontal disease.

In a paper published in 2018, scientists reported on a study undertaken in a rat model of metabolic syndrome. In this study, oral treatment with L. plantarum L-137 was shown to have anti-inflammatory effects on cardiac and adipose (fat) tissue. It reduced heart dysfunction, the accumulation of subcutaneous fat mass, insulin resistance, and elevated circulating IL-6 concentrations—indicating powerful inflammation-suppressing effects.37

To validate the effects of this probiotic strain on gum status in periodontal disease, scientists conducted a double-blind, placebo-controlled, randomized trial that included 39 volunteers with chronic periodontitis. Half received placebo while the other half took a capsule containing heat-treated L. plantarum L-137.11

Then, over the course of 12 weeks, researchers measured the pocket probing depth,11 which is the distance from the gum line to the bottom of the tiny pocket between the gum and tooth root. In dentistry, an instrument called a periodontal probe is commonly used to measure the depth of this space. Normal, healthy gums have a pocket probing depth of 3 mm or less. However, a depth of 4 mm or more is clinically defined as periodontal disease.38

At the end of 12 weeks, researchers found that in teeth with an initial (baseline) pocket probing depth of 4 mm or more, there was a 64% greater improvement in pocket depth in those treated with L. plantarum L-137 compared to placebo recipients.11

These results demonstrate that periodontal disease can be improved with oral L. plantarum L-137.

Considering the capacity of S. salivarius M18 to restore balance to the oral cavity's microbiome, these two probiotic bacteria—working together—represent powerful protection for oral health. And of course, healthy teeth and gums may help prevent a host of chronic diseases throughout the body.5,10

L. plantarum L-137 and S. salivarius M18 are now available in a single lozenge. This two-in-one lozenge makes it easy to quickly deliver targeted probiotics directly to the oral cavity. When combined with a regular routine of brushing and flossing, optimal oral health is well within reach.


Dental Health  

Poor oral health, which is more common among older adults, is associated with a steep increase in the risk of an array of serious disorders throughout the body including cancer, as well as cardiovascular, brain, kidney, and bone diseases.

A major cofactor in the development of periodontal disease is an imbalance in the normal microbial community of the oral cavity.

Scientists have shown that the bacterial strain S. salivarius M18 rebalances the bacterial populations of the mouth, crowding out harmful microbes.

Additionally, studies show that a heat-treated form of the bacterial strain L. plantarum L-137 boosts oral immune function, reduces inflammation, and promotes healing.

These two probiotics are available together in a lozenge that, when taken daily, protects oral health and promises whole-body benefits, too.

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


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