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).
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) Skin & Hair
Animal research on a 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 female animals 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).
2) Anti-Inflammatory Effects
Decreased levels of L. reuteri in humans in the past decades is correlated with an increase in the incidences of inflammatory diseases over the same period of time (R).
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).
In animal models of lupus nephritis, L. reuteri increased Lactobacilli in the gut, improved kidney function, reduced serum autoantibodies, and prolonged survival (R).
3) Lowers Stress and Pain Perception
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) Increases Vitamin D
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) Helps Gut Health
Our gut bacteria need to consume tryptophan in order to make serotonin, which is crucial for proper gut function (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).
Infants also increased bowel frequency even at a dosage of 100 million cfu (colony forming units) (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).
6) Increases Vitamin B12 and B9 (Folate)
Like many other Lactobacillus spp., several L. reuteri strains are able to produce different types of vitamins, including vitamin B12 (cobalamin) and B9 (folate).
At least 4 L. reuteri strains with various origins have been found to produce B12. Among these strains, L. reuteri CRL1098 (isolated from sourdough) and L. reuteri JCM1112 are the most studied (R).
In one study, the administration of L. reuteri CRL1098 together with a diet lacking vitamin B12 was shown to ameliorate pathologies in B12-deficient pregnant female mice and their offspring (R).
7) Thyroid Health
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).
8) Lowers Cholesterol
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).
9) Speeds Wound Healing
Supplementing the rat microbiome with Lactobacillus reuteri in drinking water cuts wound-healing time in half compared to control animals (R).
10) Helps Prevent Infections
L. reuteri can produce antimicrobial molecules, such as alcohol, reuterin, lactic acid, acetic acid, and reutericyclin. Due to its antimicrobial activity, L. reuteri is able to inhibit the colonization of disease-causing microbes (R).
Reuterin can inhibit a wide range of microorganisms, mainly Gram-negative bacteria
Of the 8 probiotic strains tested in the lab, Lactobacillus reuteri ATCC 55730 showed the strongest inhibition of Candida albicans in the mouth (R).
There is evidence showing the benefit of L. reuteri against pneumoviruses, circoviruses, rotaviruses, coxsackieviruses, and papillomaviruses (R).
It has been suggested that L. reuteri ameliorates viral infection by regulating the microbiota and secreting metabolites that have antiviral components (R).
Some studies have shown that L. reuteri has the potential to completely eradicate H. pylori from the intestine (R).
A 2-week treatment with Lactobacillus reuteri DSM17648 significantly reduced H. pylori overgrowth in otherwise healthy adults (R).
There are more than 8 studies in humans showing various L reuteri strains reducing H pylori load or reducing symptoms from it after a few weeks (R).
It has been suggested that L. reuteri works by competing with H. pylori and inhibiting its binding to glycolipid receptors. The competition reduces the bacterial load of H. pylori and decreases the related symptoms (R).
Other Bacterial 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). The exopolysaccharides synthesized by L. reuteri is able to inhibit E. coli adhesion to pig cells (R).
An antibiotic produced by Lactobacillus reuteri, called reutericyclin, can kill C. difficile infections (R).
11) Good For 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).
Lactobacillus reuteri lozenges were shown to fight oral candida in a study of older patients (R).
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).
13) Sex Drive
Lactobacillus reuteri‘s additional perk of strengthening sex drive makes the probiotic an attractive supplement for men (R).
Eating probiotic yogurt or purified probiotic bacteria induced more acidic conditions in the skin, mouth, vagina, and rectum of female mice (R).
An acidic pH in the vagina correlates with the time of peak fertility, estimated to be around age 25 (R).
The microbiota composition varies between lean and obese individuals (R).
It seems like some strains of L. reuteri may cause weight gain, while other strains can cause weight loss (R).
A surprisingly high level of Lactobacillus species has been found in the microbiota of obese people, especially L. reuteri. In fact, when individuals had strains of L. reuteri that are resistant to antibiotics (vancomycin), they gained weight after antibiotic (vancomycin) treatment (R, R).
However, in a randomized, double-blind and placebo-controlled clinical trial, taking L. reuteri JBD301 for 12 weeks significantly reduced body weight in overweight adults (R).
These results seem conflicting because some L. reuteri strains can cause weight gain, while others cause weight loss (R).
In a study that tested different strains of L. reuteri, only PTA 4659 efficiently reduced the body weight of mice fed with high-fat diet (HFD), whereas L6798-treated mice even gained some weight (R, R).
L. reuteri GMNL-263 reduces both insulin resistance and fatty liver in rats (R).