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Alex Manos | 04 Feb 2025 | Gut Health

Lactobacillus reuteri DSM17938

Lactobacillus reuteri DSM17938: A Probiotic for Gut and Brain Health

Probiotics have gained significant attention for their role in gut health, immune function, and even brain development. Among the most researched probiotic strains is Lactobacillus reuteri DSM17938, a specific strain derived from Lactobacillus reuteri ATCC 55730 but without antibiotic resistance genes, making it safer for human use.

This powerful probiotic has been extensively studied for its benefits in managing methane-related constipation, colic, diarrhoea, gut pain, and neurodevelopmental disorders as well as H. Pylori eradication. In this blog, we’ll explore its scientific-backed effects and how it may help improve overall health.

Recommended Product: Biogaia and Gastrus (the latter for neurodevelopmental disorders).

What is Lactobacillus reuteri DSM17938?

Lactobacillus reuteri is a naturally occurring gut bactera found in the intestines of humans and animals. However, due to modern dietary and environmental factors, many people have low levels of L. reuteri, which may contribute to digestive issues, immune dysfunction, and inflammatory conditions.

The DSM17938 strain is one of the most studied and commercially available versions, commonly found in probiotic supplements like BioGaia. This strain is known for producing reuterin, an antimicrobial compound that helps balance gut bacteria by inhibiting harmful pathogens while supporting beneficial microbes.

Methane, SIBO, and Chronic Constipation

One of the most common digestive issues is methane-dominant Small Intestinal Bacterial Overgrowth (SIBO), now classified as Intestinal Methanogen Overgrowth, often associated with chronic constipation. High levels of methane-producing archaea, such as Methanobrevibacter smithii, slow down gut motility, and contribute to hard, infrequent stools.

How L. reuteri DSM17938 helps:

  • Reduces methane production: Studies (source) suggest that L. reuteri can reduce methanogen populations, potentially lowering methane levels and relieving constipation.
  • Increases gut motility: It has been shown to stimulate intestinal contractions, helping to promote bowel regularity in individuals with slow transit constipation (source).
  • Balances gut microbiome: By producing reuterin, it inhibits overgrowth of harmful bacteria, supporting a more diverse and healthy microbiome (source).

In one study (source) L. reuteri proved helpful in treating constipation in childhood anorexia and contributed to faster nutritional recovery.

Who can benefit?

  • People with methane-dominant SIBO.
  • Those with chronic constipation and slow gut motility.
  • Individuals struggling with hard, difficult-to-pass stools.

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Infantile Colic: A Natural Relief For Crying Babies

Colic, defined as excessive crying in infants, is a distressing condition affecting up to 20% of newborns. Although the exact cause remains unclear, colic has been linked to gut dysbiosis, inflammation, and excessive gas production.

How L. reuteri DSM17938 Helps (source):

  • Reduces crying time: Multiple clinical trials  (source) show that infants supplemented with L. reuteri DSM17938 experience significantly shorter crying episodes compared to placebo groups (Savino et al., 2010).
  • Improves gut microbiome: It increases beneficial bacteria like Lactobacilli and Bifidobacteria, while reducing harmful pathogens such as Escherichia coli.
  • Decreases gas and bloating: By promoting gut motility and reducing inflammation, it helps alleviate the intestinal discomfort that contributes to colic.

Who can benefit?

  • Infants with unexplained excessive crying.
  • Babies with gas, bloating, or reflux.
  • Parents looking for a natural, non-medicated solution for colic.

Not all research has found positive findings for this strain of probiotic (source). This really isn’t surprising and should, in my opinion, generally be considered  for this reason. Our first child had colic and this probiotic made a clear difference and helped us all function(!).

Diarrhoea: Protection Against Gut Infections

Acute diarrhoea, particularly infectious diarrhoea caused by bacteria and viruses, is a leading cause of dehydration and hospitalisations worldwide. Probiotics like L. reuteri DSM17938 can help prevent and shorten the duration of diarrhoea (source).

How L. reuteri DSM17938 Helps:

  • Reduces duration of diarrhoea: Studies have shown that this probiotic can shorten diarrhoea episodes in both children and adults by enhancing gut microbiome resilience.
  • Enhances immune function: It strengthens gut immunity, reducing the severity of infections and promoting faster recovery.

Who can benefit?

  • Children and adults experiencing acute diarrhoea.
  • Individuals taking antibiotics, to prevent antibiotic-associated diarrhoea.
  • Traveler’s prone to traveler’s diarrhoea.

Gut Pain and Inflammation: IBS and Functional Abdominal Pain

Chronic gut pain, bloating, and discomfort are common symptoms of Irritable Bowel Syndrome (IBS) and functional gastrointestinal disorders. These conditions often involve low-grade inflammation, gut permeability (“leaky gut”), and microbiome imbalances.

How L. reuteri DSM17938 Helps (source, source):

  • Reduces inflammation: It lowers pro-inflammatory cytokines, helping to soothe gut irritation and discomfort.
  • Supports gut barrier integrity: It strengthens the gut lining, reducing “leaky gut” symptoms that contribute to inflammation.
  • Modulates pain perception: Studies suggest that L. reuteri influences the gut-brain axis, helping to modulate pain sensitivity.

Who can benefit?

  • People with IBS, bloating, and cramping.
  • Those with chronic gut pain or post-infectious IBS.
  • Individuals with low-grade gut inflammation.

Neurodevelopmental Disorders: Autism, Anxiety, and Mood

The gut-brain axis plays a key role in mood, behaviour, and neurodevelopment. Recent research suggests that gut bacteria influence neurotransmitter production, including serotonin and GABA, which affect mood and stress responses.

Lactobacillus reuteri DSM 17938 is known to produce GABA, a neurotransmitter that helps promote relaxation. Research by Brenner et al. has shown that this probiotic strain can also lower C-reactive protein, a marker of inflammation, suggesting it may help reduce stress-related inflammation and its negative effects on mental and neurological health. Because of these properties, L. reuteri DSM 17938 is considered a psychobiotic—a probiotic that supports mental well-being (source).

Beyond its ability to produce GABA and regulate inflammation, this strain has additional benefits that may contribute to its positive effects on the brain. For instance, it produces reuterin, an antimicrobial compound that helps control harmful bacteria in the gut, potentially preventing imbalances linked to anxiety and depression. Additionally, L. reuteri DSM 17938 can influence gut microbiota by increasing beneficial bacteria like Bifidobacterium while reducing harmful ones like Clostridium. This shift may boost the production of short-chain fatty acids and other neuroactive compounds, which play a role in brain function and mood regulation (source).

How L. reuteri DSM17938 Helps (source, source):

  • Enhances social behaviour: In animal studies, L. reuteri supplementation improved social behaviours and oxytocin levels, suggesting potential benefits for autism spectrum disorder (ASD).
  • Reduces stress and anxiety: It helps regulate cortisol levels, reducing the physiological effects of stress.
  • Supports neurotransmitter production: L. reuteri influences serotonin and dopamine pathways, which are critical for mood and cognition.

Recommended Product: Gastrus

Who Can Benefit?

  • Children with autism or social impairments.
  • Individuals struggling with stress, anxiety, or mood imbalances.
  • Those looking to support brain health through gut optimisation.

H.Pylori

A randomised, double-blind, placebo-controlled trial investigated the effectiveness of Lactobacillus reuteri DSM 17648 as an adjunct to standard triple therapy for H.Pylori eradication. Ninety treatment-naïve H. pylori-positive patients were assigned to receive either L. reuteri or a placebo for four weeks following their antibiotic regimen. The study found that the eradication rate was significantly higher in the probiotic group compared to the placebo group, with a 22.2% improvement in the intention-to-treat analysis and a 24.3% improvement in the per-protocol analysis. Additionally, patients taking L. reuteri experienced significant reductions in gastrointestinal symptoms, including indigestion, constipation, and abdominal pain, as measured by the Gastrointestinal Symptom Rating Scale (GSRS). The probiotic group also reported fewer adverse effects, with significantly lower rates of headaches and abdominal pain.

These findings suggest that L. reuteri DSM 17648 enhances H. pylori eradication success and improves gastrointestinal symptoms while reducing side effects, making it a beneficial adjunct to standard antibiotic therapy. (source)

Conclusion: Why L. reuteri DSM17938 is a Powerful Probiotic

Recommended Product: Biogaia

Lactobacillus reuteri DSM17938 is a well-researched probiotic that offers wide-ranging benefits for gut, brain, and immune health. Whether you struggle with chronic constipation, colic, diarrhoea, gut pain, or neurodevelopmental concerns, this probiotic strain has been shown to support digestive function, reduce inflammation, and enhance gut-brain communication.

Key Takeaways:

✔ Reduces methane production and improves constipation.
✔ Alleviates colic and crying in infants.
✔ Shortens the duration of diarrhoea and protects against infections.
✔ Reduces gut pain and inflammation in IBS.
✔ Supports brain function, mood, and social behaviour.

For best results, L. reuteri DSM17938 should be taken consistently in supplement form, such as BioGaia, and paired with a gut-friendly diet rich in fiber and fermented foods. If you suffer from any of these conditions, this probiotic may be a natural, science-backed solution for improving gut and overall health.

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