BioGaia Gastrus Probiotic (L.Ruteri)

BioGaia Gastrus® Probiotic

Two targeted L. reuteri probiotic strains for digestive comfort, regularity, and a balanced gut microbiome.

BioGaia Gastrus® takes a different approach to probiotic support. Instead of relying on an extremely high CFU count or a long list of unidentified organisms, it provides two precisely identified strains of Limosilactobacillus reuteri — ATCC PTA 6475 and DSM 17938 — developed and studied by BioGaia.

Each serving provides a minimum of 200 million CFU of the Gastrus® blend to support healthy gastrointestinal function, bowel regularity, and occasional digestive discomfort such as gas and bloating.

• Support a healthy, balanced gut microbiome
• Promote normal digestive and gastrointestinal function
• Support bowel regularity
• Help ease occasional gas, bloating, and digestive discomfort

Why strain-specific probiotics matter

With probiotics, the strain matters — not just the species or the number on the label.

BioGaia Gastrus® contains two specifically identified L. reuteri strains: ATCC PTA 6475 and DSM 17938. BioGaia developed and patented this Gastrus® combination and has focused extensively on research involving specific probiotic strains rather than simply maximizing CFU counts.

That makes Gastrus® a more targeted choice for people looking for L. reuteri probiotic support for everyday digestive and gastrointestinal health.

Targeted digestive support

The gastrointestinal tract contains a complex community of microorganisms that influence digestive function and the intestinal environment.

BioGaia states that regular use of Gastrus® can support a healthy functioning GI system, regularity, and relief from occasional constipation, gas, bloating, and GI discomfort.

What’s inside

Each serving provides a minimum of 200 million CFU from two targeted probiotic strains:

L. reuteri ATCC PTA 6475
A specifically identified L. reuteri strain used in BioGaia research.

L. reuteri DSM 17938
A second well-characterized L. reuteri strain included in the proprietary Gastrus® blend.

Together, these strains provide targeted probiotic support without relying on an unnecessarily large number of strains or an exceptionally high CFU count.

What about bone health?

L. reuteri ATCC PTA 6475 has also been studied in human bone-health research, but I would not market Gastrus® as a bone-health supplement based on the current evidence.

A 2018 randomized trial in older women with low bone mineral density found less tibial bone loss with L. reuteri 6475 than placebo. However, a larger 2024 randomized trial in early postmenopausal women found no significant reduction in bone loss over two years. The research is interesting, but it remains an area of investigation rather than a strong consumer-facing claim for this product.

Suggested use

Take 1 serving daily, or as directed by your healthcare professional. BioGaia's current U.S. directions specify one chewable tablet or one capsule daily depending on the product format.

Why we like it

Gastrus® focuses on two precisely identified L. reuteri strains rather than an oversized blend or eye-catching CFU number. It's a targeted option for people looking to support digestive comfort, bowel regularity, and a healthy gastrointestinal environment.

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.