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Lactobacillus reuteri

Lactobacillus reuteri is a species of probiotic bacteria. It may provide some benefits for cholesterol levels, reducing H. pylori levels (the pathogenic bacterium which contributes to ulcers), female urinary tract and vaginal health, and infant gastrointestinal health.

Our evidence-based analysis on lactobacillus reuteri features 150 unique references to scientific papers.

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Summary of Lactobacillus reuteri

Primary information, health benefits, side effects, usage, and other important details

Lactobacillus reuteri is a species of bacteria that belongs to one of the major lactic-acid producing genera of bacteria. It can be found in the human intestinal tract, though not always and often in relatively low numbers. Lactobacillus reuteri is also found in the gut of other mammals and birds.

Initially, Lactobacillus reuteri was used to treat necrotizing colitis, a gastrointestinal disease characterized by infection and inflammation that is particularly dangerous for infants, particularly those born prematurely. Lactobacillus reuteri was used due to its anti-inflammatory effects. The research on Lactobacillus reuteri and necrotizing colitis used the Lactobacillus reuteri strains ATCC 55730 and its daughter strain DSM 17938, both of which can survive oral supplementation.

Interest in Lactobacillus reuteri grew after research confirmed that changing aspects of the digestive system can influence the immune system. A strain of Lactobacillus reuteri called ATCC PTA 6475 has been found to improve levels of testosterone and oxytocin, as well as skin quality in animal studies. Research on animals has also found potential benefits for hair quality, bone mass and preventing weight gain from obesity-causing diets.

One of the ways Lactobacillus reuteri may work involves a kind of T cell called a Treg cell (a T cell that down-REGulates the immune system in part by producing a cytokine called IL-10). Lactobacillus reuteri increases the amount of Treg cells in the body, which suppresses the actions of another kind of T cell called a Th17 cell (which secretes IL-17). Preserving or reversing this process (either by increasing IL-10 or by blocking IL-17) appears to provide therapeutic benefits.

Lactobacillus reuteri increases the number of Treg cells in the intestines, which can then be absorbed back into the blood to benefit the rest of the body.

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How to Take

Recommended dosage, active amounts, other details

Certain strains of Lactobacillus reuteri are more appropriate for supplementation than others. Lactobacillus reuteri ATCC 55730, DSM 17938, and ATCC 6475 are all known to survive oral supplementation, even without an enteric capsule.

Research doses of Lactobacillus reuteri are in the range of 1x109 to 1x1011 (one billion to one hundred billion) colony-forming units (CFU) taken over the course of a day. Both single doses and multiple split doses per day have been found to be effective, though further research is needed to determine whether one is more effective than the other.

At least one study suggests that supplementing Lactobacillus reuteri every other day is just as effective as daily dosing.

Lactobacillus reuteri can be taken with food. Don’t take Lactobacillus reuteri with a hot beverage to allow for the survival of the bacteria.

Once supplementation is stopped, intestinal colonization will start to revert to normal. Further research is needed to establish the exact time frame, but it has been observed to occur between half a week to one month after supplementation is stopped. The actual time may depend on whether supplementation took place over the long term or the short term.

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Human Effect Matrix

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The Human Effect Matrix summarizes human studies to tell you what effects Lactobacillus reuteri has on your body, how much evidence there is, and how strong these effects are.

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Grade Level of Evidence
Robust research conducted with repeated double-blind clinical trials
Multiple studies where at least two are double-blind and placebo controlled
Single double-blind study or multiple cohort studies
Uncontrolled or observational studies only
Level of Evidence
? The amount of high quality evidence. The more evidence, the more we can trust the results.
Outcome Magnitude of effect
? The direction and size of the supplement's impact on each outcome. Some supplements can have an increasing effect, others have a decreasing effect, and others have no effect.
Consistency of research results
? Scientific research does not always agree. HIGH or VERY HIGH means that most of the scientific research agrees.
Notes
grade-a Minor Very High See all 7 studies
Supplementation of 108 CFU of DSM 17938 (no other strain tested) has been associated with greatly reducing infantile colic within a week and increasing potency for one month, but the available evidence appears to be potentially biased and the lone independent study failed to find a protective effect of supplementation.
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Studies Excluded from Consideration

Note: The above table includes data on all strains of L. reuteri whether by capsule or via food product, but will exclude studies that use combinations of species (ie. L. reuteri with L. rhamnosus)

  • Confounded with lactobacillus rhamnosus[1][2][3]

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Things to Note

Is a Form Of

Primary Function:

Also Known As

ATCC PTA 6475, ATCC 55730, DSM 17938, NCIMB 30242

Do Not Confuse With

Lactobacillus casei (Yakult)

  • Some strains (ATCC PTA 6475, ATCC 55730, DSM 17938) can survive stomach acid without requiring an enteric capsule

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