Your Basket

0 item(s)

Free delivery on tests

Alex Manos | 04 Feb 2025 | Gut Health

Lactobacillus reuteri DSM 17938

The One Probiotic That Actually Works for Constipation, Colic, and Gut Pain (According to 200+ Studies)

If you’ve tried every probiotic on the shelf and still struggle with constipation, bloating, or endless baby crying—this might be the most important article you read this year. Most probiotics are a waste of money. They contain random strains with little research, survive poorly in your gut, and rarely deliver results you can actually feel. But one probiotic strain stands apart: Lactobacillus reuteri DSM 17938.

With over 200 clinical studies backing its effects, this is the probiotic that actually works—and it’s the active ingredient in Biogaia, one of the most researched probiotic supplements in the world.

Here’s why thousands of parents, constipation sufferers, and gut health seekers are finally getting relief with this specific strain.

What Makes Lactobacillus reuteri DSM 17938 Different?

Unlike generic probiotic blends, L. reuteri DSM 17938:

  • Produces reuterin—a natural antimicrobial compound that rebalances your gut by targeting harmful bacteria while protecting good bacteria
  • Actually survives stomach acid to reach your intestines alive
  • Has been tested in over 200 clinical trials on real humans (not just petri dishes)
  • Works for multiple conditions—from infant colic to adult constipation to IBS pain

This strain was specifically developed to be antibiotic-resistance-free, making it safe for long-term use in both children and adults.

The bottom line: If you’re going to take ONE probiotic, this is the strain with the most evidence behind it.

Problem #1: Chronic Constipation and Methane SIBO

Do you:

  • Go days without a bowel movement?
  • Strain on the toilet despite eating fiber?
  • Feel constantly bloated and backed up?
  • Have hard, difficult-to-pass stools?

You might have methane-dominant SIBO (Small Intestinal Bacterial Overgrowth), recently reclassified as Intestinal Methanogen Overgrowth. This condition occurs when methane-producing organisms slow down your gut motility, causing chronic constipation.

How L. reuteri DSM 17938 Helps:

Clinical studies show this probiotic strain:

  • Reduces methane production by limiting methanogen populations
  • Increases gut motility—stimulating intestinal contractions to move things along
  • Balances the microbiome through reuterin production, which inhibits harmful bacterial overgrowth

In one study on children with constipation and anorexia, L. reuteri not only relieved constipation but also contributed to faster nutritional recovery.

Real-world result: Many users report bowel movements becoming regular within 2-4 weeks of daily use.

👉 Try Biogaia for Constipation Relief →

Problem #2: Infant Colic (The Exhausting Cycle of Crying)

Is your baby:

  • Crying for 3+ hours a day with no clear cause?
  • Pulling their legs up in pain?
  • Struggling with gas and bloating?
  • Making your entire household sleep-deprived and stressed?

Up to 20% of newborns experience colic—excessive, unexplained crying that peaks around 6 weeks of age. While the exact cause remains debated, research links colic to gut dysbiosis, inflammation, and excessive gas.

How L. reuteri DSM 17938 Helps Colicky Babies:

Multiple clinical trials have shown that infants given L. reuteri DSM 17938:

  • Experience significantly shorter crying episodes compared to placebo groups
  • Show improved gut microbiome balance—with more beneficial Lactobacilli and Bifidobacteria
  • Have reduced gas and bloating due to better gut motility and lower inflammation

Important note: Not every study shows positive results (which is true for most interventions), but the majority of research—and countless parent experiences—support its effectiveness.

Parent perspective: Our own first child had severe colic, and Biogaia made a noticeable difference within days. It gave us back our sanity.

👉 Get Biogaia for Colic Relief →

Problem #3: IBS, Gut Pain, and Chronic Bloating

Do you suffer from:

  • Daily bloating that makes you look pregnant?
  • Cramping and abdominal pain after meals?
  • Alternating constipation and diarrhoea?
  • A “sensitive stomach” that limits what you can eat?

Irritable Bowel Syndrome (IBS) and functional gut disorders affect millions of people. These conditions involve low-grade inflammation, increased gut permeability (“leaky gut”), and microbiome imbalances.

How L. reuteri DSM 17938 Helps:

Research shows this probiotic:

  • Reduces inflammatory markers like pro-inflammatory cytokines, soothing gut irritation
  • Strengthens the gut barrier—helping to repair leaky gut and reduce systemic inflammation
  • Modulates pain perception through the gut-brain axis, potentially reducing pain sensitivity

Who benefits most:

  • People with IBS (especially IBS-C with constipation)
  • Those with chronic bloating and cramping
  • Anyone with post-infectious IBS or ongoing gut inflammation

👉 Support Your Gut with Biogaia →

Bonus Benefits: Brain Health, Mood, and Immunity

The gut-brain connection is real—and L. reuteri DSM 17938 is classified as a psychobiotic, meaning it directly supports mental well-being.

How It Works:

This probiotic strain:

  • Produces GABA—a calming neurotransmitter that promotes relaxation
  • Lowers C-reactive protein—a marker of inflammation linked to anxiety and depression
  • Influences neurotransmitter pathways—including serotonin and dopamine production
  • Increases beneficial bacteria like Bifidobacterium while reducing harmful strains like Clostridium

Animal studies have even shown that L. reuteri supplementation improves social behavior and increases oxytocin levels, suggesting potential benefits for neurodevelopmental concerns like autism spectrum disorder.

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 Lactobacillus 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)

Why Biogaia Is the Best Choice

When you’re investing in a probiotic, you want:

The exact strain used in clinical studies (not a generic version)
Guaranteed potency through manufacturing and shelf life
Easy-to-take formats for both adults and children
A trusted brand with decades of research backing

Biogaia checks all these boxes. It contains the clinically-studied Lactobacillus reuteri DSM 17938 strain in formats including:

  • Drops for infants
  • Chewable tablets for children and adults
  • Easy daily dosing

Investment perspective: At roughly £1-2 per day, Biogaia costs less than a coffee—but delivers measurable improvements in gut function, sleep quality (for parents of colicky babies), and overall well-being.

👉 Order Biogaia Now →

How to Use Biogaia for Best Results

Dosage:

  • Infants (colic): 5 drops daily
  • Children and adults (constipation, IBS, general gut health): 1 chewable tablet daily

Timeline:

  • Most people notice improvements within 2-4 weeks
  • For best results, take consistently for at least 8-12 weeks
  • Pair with a gut-friendly diet rich in fiber and fermented foods

Pro tip: Probiotics work best when combined with dietary improvements. If you’re serious about gut health, consider testing your microbiome first to understand what’s actually going on.

Not Sure What’s Causing Your Gut Issues?

Before investing in supplements, it helps to know what’s actually wrong with your gut.

Our gut health tests can identify:

  • Bacterial overgrowths (including SIBO)
  • Microbiome imbalances
  • Inflammatory markers
  • Digestive enzyme deficiencies
  • Parasite or pathogen presence

Why test first?
Because while Lactobacillus reuteri DSM 17938 works for many conditions, targeted treatment based on test results often delivers faster, more dramatic improvements.

Discover the reasons for your gut symptoms.

View our gut health tests

The Bottom Line: This Probiotic Has the Research Behind It

Most probiotics are overhyped. But Lactobacillus reuteri DSM 17938 isn’t most probiotics.

With over 200 clinical studies demonstrating real benefits for:

✅ Chronic constipation and methane SIBO

✅ Infant colic and excessive crying

✅ IBS, gut pain, and bloating

✅ Diarrhea prevention and recovery

✅ Brain health and mood regulation

Biogaia delivers the clinically-studied strain in a format that’s easy to take and proven to work.

If you’ve been struggling with gut issues—or have a crying baby who won’t settle—this might be the science-backed solution you’ve been searching for.

Frequently Asked Questions

How long does it take to work?
Most people notice improvements within 2-4 weeks, though some see results sooner (especially with infant colic).

Is it safe for long-term use?
Yes. Lactobacillus reuteri DSM 17938 has been extensively tested for safety and is free from antibiotic-resistance genes.

Can I take it with other probiotics?
Yes, though many people find Lactobacillus reuteri DSM 17938 alone is sufficient for their needs.

Will it help with weight loss?
While not primarily a weight-loss probiotic, improving gut health and reducing constipation can support healthy weight management.

What if it doesn’t work for me?
While most people benefit, individual responses vary. Consider getting a gut health test to identify specific issues that may require targeted treatment.

Ready to finally fix your gut?

👉 Order Biogaia Now →

Other articles you might like