Lactobacillus reuteri is one of the most studied strains of probiotic bacteria, boasting a variety of proven health benefits. From improving your looks to increasing Vitamin D, Lactobacillus reuteri is worth checking out.

What is Lactobacillus reuteri?

Lactobacillus reuteri is a strain of lactic acid bacteria that live in the intestines, and occasionally the stomachs, of humans (although not all individuals), other mammals, and birds.

Its name comes from German microbiologist, Gerhard Reuter, who discovered it in samples of human intestine and feces in the 1960s.

Different strains of Lactobacillus reuteri have been shown to have different physiological effects. For example, Lactobacillus reuteri DSMZ 17648, trademarked “Pylopass” is used for H. pylori (R), while Lactobacillus reuteri NCIMB 30242, trademarked “Cardioviva” is used to address high cholesterol (R).

In the 1960s, 30-40 percent of the population had Lactobacillus reuteri as a part of their microbiome. Today it is found in only 10-20 percent (R, R2).

Lactobacillus reuteri Snapshot


  • Promotes beautiful skin and thick, lustrous hair.
  • Helps fight infections.
  • Is anti-inflammatory and increases beneficial TREGs.
  • Improves gut health – decreasing IBS and IBD symptoms.
  • Lowers cholesterol.


  • May not be good for those with histamine intolerance.
  • May cause weight gain in some people.

Benefits of Lactobacillus reuteri

1) Lactobacillus reuteri Promotes Sex Appeal

Animal research on an Lactobacillus reuteri strain called ATCC PTA 6475 has shown potential for improving skin quality (thickness and “glow”) and creating thick, lustrous hair (R).

The probiotic improved skin and hair quality in both sexes, but in females caused a dramatic improvement in the level of shine of their hair. The Lactobacillus reuteri caused females to have a more acidic pH, which was found to correlate with hair luster (R).

Therefore, Lactobacillus reuteri bacteria may restore women’s skin and hair to youthful splendor (R).

When translated into human terms, an acidic pH in the vagina correlates with the time of peak fertility, estimated to be around age 25 (R).

Lactobacillus reuteri was also shown to improve levels of the “feel good” hormone oxytocin (needs IL-10), which is important for bonding (R).

Lactobacillus reuteri increases testosterone (needs IL-10(R).

Lactobacillus reuteri‘s ability to increase testosterone and lower inflammation can potentially benefit implications for male pattern baldness. High IL-17 inflammation can inhibit hair growth, and Lactobacillus reuteri has been shown to suppress IL-17 (R).

Lactobacillus reuteri‘s additional perk of strengthening sex drive makes the probiotic an attractive supplement for men (R).

2) Lactobacillus reuteri is Anti-Inflammatory

Lactobacillus reuteri has been shown to increase Treg cells in the body, causing an increase in the cytokine IL-10. As a result, Th17 (and its production of IL-17) is suppressed (R, R2).

Lactobacillus reuteri inhibits NF-κB, one of the most important factors in reducing whole-body inflammation (R). To learn more about NF-kB, read my post, How To Inhibit NF-kB: The Key To Health And Master Control of Inflammation.

Note: Lactobacillus reuteri may not be good for histamine intolerance.

Lactobacillus reuteri is able to convert dietary l-histidine into histamine, increasing IL-10, and suppressing TNF-α (by activating the histamine H2 receptor) (R, R2).

3) Lactobacillus reuteri Lowers Stress and Pain Perception

In animal models of gut pain, Lactobacillus reuteri has been shown to lower the activation of the nervous system and lessen the pain (RR2).

Lactobacillus reuteri ingestion impacts the nerves in such a way that it may slow gut motility (improving cases of diarrhea) and decrease pain perception (R).

4) Lactobacillus reuteri Increases Vitamin D

Taking Lactobacillus reuteri increased blood levels of vitamin D3 by 25.5% in a Canadian study (R).

According to the authors of the study, this is the first time blood levels of vitamin D3 have been increased by oral probiotic supplementation (R).

5) Lactobacillus reuteri Helps Gut Health

Our gut bacteria need to consume tryptophan in order to make serotonin, which is crucial for proper gut function (R).

When our gut bacteria consume sugar instead of tryptophan, we are more susceptible to Candida and other infections (by not producing AhR ligands) (R).

Lactobacillus reuteri switches our bacteria’s primary food source from sugar to tryptophan, which helps produce serotonin, and protects our gut from infections.  This lessens susceptibility to gut problems and IBS (R).

Lactobacillus reuteri helps constipation, increasing the number of bowel movements people have. People went from having 3.89 bowel movements per week to 5.28 (R).

Infants also increased bowel frequency even at a dosage of 100 million cfu (colony forming units) (R).

Lactobacillus reuteri also decreases the incidence of diarrhea in children (R). 

It inhibited the onset of colitis in mice (R) and may reduce stress-induced colitis flare-ups (R).

Yogurt containing Lactobacillus reuteri RC-14 and Lactobacillus rhamnosus GR-1 increased T regulatory cells in patients with Inflammatory Bowel Disease and decreased inflammation (TNF-alpha and IL-12) (R).

A rectal enema of Lactobacillus reuteri reduced gut lining inflammation in children with active Ulcerative Colitis (R).

6) Lactobacillus reuteri Fights Candida

Lactobacillus reuteri RC-14 alone and together with Lactobacillus rhamnosus GR-1 can inhibit the growth of candida in the vagina (R, R2).

Oral Lactobacillus reuteri supplementation was effective as nystatin in a study preterm infants and more effective at reducing the incidence of sepsis (R, R2).

Of the 8 probiotic strains tested in the lab, Lactobacillus reuteri ATCC 55730 showed the strongest inhibition of oral Candida albicans (R).

7) Lactobacillus reuteri is Good for the Thyroid

In mice, Lactobacillus reuteri increased thyroid size and activity (increasing T4 levels), lessening the fatigue and weight gain associated with aging and causing a more youthful physical appearance (R).

Crucial to these anti-aging effects is Lactobacillus reuteri‘s ability to increase anti-inflammatory T regulatory cells (R).

8) Lactobacillus reuteri Lowers Cholesterol

In one study, Lactobacillus reuteri reduced LDL cholesterol by 11.64%, reduced total cholesterol by 9.14%, non-HDL-cholesterol by 11.30% and apoB-100 by 8.41% (R).

Hs-C-reactive protein and fibrinogen were reduced by 1.05 mg/l and 14.25%, respectively (R).

Another study used microencapsulated Lactobacillus reuteri NCIMB 30242 yogurt taken twice a day over 6 weeks by adults with high cholesterol. Results included a reduction of LDL by 8.92% and total cholesterol 4.81% over the course of the study (R).

The Lactobacillus reuteri in that form and delivery method was found to work better than probiotics traditionally used and comparable to other cholesterol-lowering methods (R).

Lactobacillus reuteri lowers cholesterol, in part, by reducing the absorption of bile (by increasing the deconjugation of bile in the intestines) (R).

9) Lactobacillus reuteri Speeds Wound Healing

Supplementing the rat microbiome with Lactobacillus reuteri in drinking water cuts wound-healing time in half compared to control animals (R).

Lactobacillus reuteri enhances healing by increasing oxytocin via the vagus nerve. The oxytocin then activates Tregs (CD4+Foxp3+CD25+), which improves the repair of wounds (R).

10) Lactobacillus reuteri Protects Against Infections

Lactobacillus reuteri potently protects against Salmonella, cutting mortality rates in mice, chickens, and turkeys in half (R).

In chickens, Lactobacillus reuteri was as potent as the antibiotic gentamicin in preventing E. coli-related deaths (R).

An antibiotic produced by Lactobacillus reuteri, called reutericyclin, can kill C. difficile infections (R).

Derivatives of Lactobacillus reuteri are helpful for MRSA on the skin, destroying biofilms and reducing the infection (R).

A 2-week treatment with Lactobacillus reuteri DSM17648 significantly reduced H. pylori overgrowth in otherwise healthy adults (R).

11) Lactobacillus reuteri Promotes Oral Health

Lactobacillus reuteri fights major cavity-producing bacteria (R).

Chewing gum containing Lactobacillus reuteri decreased plaque and bleeding from the gums in two weeks (R).

Oral Lactobacillus reuteri containing tablets significantly reduced inflammation markers (TNF-α, IL-1β, and IL-17) in patients with chronic periodontitis (R).

Lactobacillus reuteri lozenges were shown to fight oral candida in a study of older patients (R).

12) Lactobacillus reuteri Produces Vitamin B12

Lactobacillus reuteri CRL1098, a strain of Lactobacillus reuteri isolated from sourdough, has been shown to produce cobalamin, otherwise known as vitamin B12 (R).

13) Lactobacillus reuteri May Help in Autism

In an animal model of social deficits in offspring, Lactobacillus reuteri was found to be 9X lower.  Supplementing with it significantly improved sociability and preference for social novelty in these offspring (R).

The main mechanism is by l reuteri increasing oxytocin, including in the hypothalamus (R).

Lactobacillus reuteri is Controversial When it Comes to Obesity

Lactobacillus reuteri GMNL-263 has proved to be effective in reducing both insulin resistance and fatty liver in rats (R).

An animal study showed Lactobacillus reuteri strain ATCC PTA 4659 to partly prevent weight gain caused by an unhealthy Western diet (R).

In a study of both humans and mice, a Western ‘fast food’ diet caused changes in gut bacteria, accumulation of belly fat and Th17 dominance. The addition of Lactobacillus reuteri ATCC 6475 with no change in diet prevented age-associated weight gain by reducing the Th17 inflammation (R).

Or, Lactobacillus reuteri may cause obesity, in this study of an unspecified strain, the results of which requires caution, since it is the first to connect that species of bacteria with obesity (R).

Additional Reading

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