Lactobacillus Reuteri DSM 17938: The Ultimate Guide

Lactobacillus Reuteri DSM 17938: The Ultimate Guide

Lactobacillus Reuteri DSM 17938: The Ultimate Guide

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Numerous clinical studies suggested that Lactobacillus Reuteri DSM 17938 may be helpful in modulating the gut microbiome, eliminating infections, and attenuating the symptoms of enteric colitis, antibiotic-associated diarrhoea (also related to the treatment of Helicobacter pylori infection), irritable bowel syndrome, inflammatory bowel disease, and chronic constipation.  (source)

You may like to also check out my article What Are The Best Probiotics to learn what probiotic might be most helpful in specific circumstances. While we can’t say that one specific strain of probiotic will work 100% of the time for a specific symptom/condition, we can say that there are specific strains that are more likely to work in specific symptoms/conditions.

Constipation And Methane

Two recent studies performed on adults and children affected by chronic constipation showed that the supplementation with L. reuteri significantly improved bowel movements.

However the researchers didn’t investigate whether this was related to methane production (we know methane production is a common cause of constipation).  So another study was conducted to explore this in more detail.

20 adults affected by functional constipation, were treated with the probiotic Lactobacillus reuteri DSM 17938 for 4 weeks. They completed a hydrogen/methane lactulose breath test at the beginning and end of this 4 week period. They also reported in their stool diary about the frequency of bowel movements as well as stool consistency.

Four weeks of L. reuteri use was associated with a significant decrease of mean methane production based on the breath test. At the beginning of the study the average methane production was 20.8 and at the end it was 8.9. Moreover, a total disappearance of methane production (less than 5ppm) was observed in 11 patients. The authors also noted that there wasn’t any significant decrease of hydrogen production.

The authors concluded that the beneficial effect of Lactobacillus reuteri DSM 17938 on chronic constipation, via a significant decrease of CH4 production.


In a systematic review with network meta-analysis that analysed 32 studies that included 2242 patients (source) Lactobacillus reuteri DSM 17938 was found to be better than other interventions for treatment of infantile colic.

In one study in particular a total of 120 infants with a mean age of 57 days (± 34.2 days) were included in a 28-day study. The mean crying time as reported by the parents in the subject diary reduced from 248 minutes on average to 46 minutes on average. The clinical response (defined as reduction of 50% in crying time) was observed in 85% of subjects. The fussiness and parental perception of colic recorded during the consultations were reduced by 66% and 72%, respectively, at study end.

Interestingly, and totally understandably, the maternal depression scores were reduced to 63% at study end.

Lactobacillus reuteri DSM 17938 was associated with a significant reduction in crying time in colicky infants, and showed improvement in maternal depression. (source)


Numerous clinical studies have been conducted to explore the function of L. reuteri in the intestines of healthy individuals, its role in regulating gut microbiome and mucosal homeostasis, in shaping the intestinal host immune system, and in ameliorating intestinal inflammation in pathological conditions, such as acute watery diarrhoea.

Shornikova et al.  examined the role of Lactobacillus reuteri DSM 17938 in acute watery diarrhoea in children and in rotavirus gastroenteritis. These authors conducted a randomised controlled clinical trial, enrolling 86 children, between 6 and 36 months of age, who tested positive for rotavirus. They randomised children to receive either 10×10 or 10×7 colony-forming units (CFU) of L. reuteri or a placebo once a day for 5 days.

They showed that the use of Lactobacillus reuteri DSM 17938 shortened the duration of the acute watery diarrhoea with a dose-related effect. Indeed, the mean duration of acute watery diarrhoea was 1.5 days in the group taking a large dosage of Lactobacillus reuteri DSM 17938, 1.9 days in the group taking a small dosage, and 2.5 days in the group taking the placebo. By the second day of treatment with L. reuteri, the acute watery diarrhoea persisted among 48% of those who took the large dosage, 70% of those who took the small dosage, and 80% of those treated with the placebo.

Francavilla et al., in their randomised placebo-controlled clinical trial, which included 35 children in the L. reuteri group and 34 in the placebo group, reported that supplementation with Lactobacillus reuteri DSM 17938, at a dosage of 4 × 108 CFU/day for 7 days, reduced the duration of acute watery diarrhoea, with the maximum effect on the second and third day, in children aged between 3 months and 3 years, without reported side effects.

Dinleyici et al. carried out two multicenter randomised clinical trials and found that the use of L. reuteri was able to decrease the duration of acute watery diarrhoea up to 15 h in children aged between 3 months and 5 years. Moreover, it was able to reduce the length of hospital stay.

After two days of treatment with L. reuteri, ~55% of children were diarrhoea free vs. only 15% of children in the control group, with a greater effectiveness of the intervention between 48 and 72 h after using five drops containing 108 CFU Lactobacillus reuteri DSM 17938, and with a safe, well-tolerated and effective profile in the pediatric outpatient setting.

Systematic review with meta-analysis

In therapeutic settings, Lactobacillus reuteri DSM 17938 administration reduces the duration of diarrhoea and increases the chance of cure. In preventive settings, L. reuteri has the potential to reduce the risk of community-acquired diarrhoea in otherwise healthy children

Neurodevelopmental Disorders

The role of gut microbiome has emerged as a potential target for the treatment of both neurodegenerative diseases and neurodevelopmental disorders like attention-deficit hyperactivity disorder (ADHD)/autism spectrum disorders (ASD) as a result of the decoding of the human genome and advances in our understanding of the human gut microbiome, including its interactions with the human brain.

According to recent investigations, several lactobacillus strains, including L. Paracasei 37L. Planetarium 128, Lactobacillus reuteri DSM 17938, and Bifidobacterium longum, have been effective in treating children’s neurodevelopmental disorders such as ASD and ADHD. (source)


Lactobacillus reuteri DSM 17938 is one of the most researched probiotics on the market and could be considered when suffering with intestinal methanogen overgrowth, or any of the other conditions mentioned throughout this blog.

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