Lactobacillus reuteri DSM 17938

Lactobacillus reuteri DSM 17938 is a naturally occurring, friendly bacterium that has lived in the human gut for thousands of years — it's even been found in breast milk. This specific strain was carefully developed to be free of any antibiotic-resistance traits, making it exceptionally safe for the tiniest members of your family. Think of it as a tiny peacekeeping team that moves into your baby's gut, pushes out the troublemakers causing discomfort, and helps create an environment where digestion can finally happen smoothly. It does this partly by producing a natural substance called reuterin, which discourages harmful bacteria from setting up camp, and also by sending tiny messenger signals (called microvesicles) that help the gut walls calm down, move food along more efficiently, and lower the pain signals that can make your baby so uncomfortable.

The most celebrated use of this strain is for infantile colic — that exhausting, heartbreaking cycle of a healthy baby screaming for hours on end, often in the evenings, for no obvious reason. Multiple clinical trials have put this probiotic up against placebos, dietary changes, acupuncture, and other interventions, and it consistently comes out on top for reducing crying time. In real-world studies, parents reported daily crying time dropping dramatically — from over four hours a day down to under an hour — within just three weeks. An impressive 85% of parents in one large observational study saw crying time cut by at least half. Importantly, mothers of colicky babies also reported feeling less stressed and less depressed as their babies became calmer, underscoring the real-world family impact of this tiny probiotic. Beyond colic, this strain is well-supported for helping children recover from acute gastroenteritis (stomach bugs and diarrhea). In multiple meta-analyses, children given this probiotic bounced back from diarrhea significantly faster — sometimes cutting illness duration by a full day or more — and were more likely to be better within the first three days compared to children who received no treatment. It has also been studied for preterm and premature babies, where it appeared to help improve feeding tolerance and gut readiness, allowing tiny neonates to reach full feedings sooner.

One of the most reassuring things about Lactobacillus reuteri DSM 17938 is its outstanding safety record across a large body of research — no serious adverse events have been reported in clinical trials, even at higher-than-standard doses, and this holds true even for premature newborns. It is well-suited for breastfed infants experiencing colic, and evidence is particularly strong for this group. For diarrhea in children, it is best used as a complement to standard oral rehydration therapy — think of it as a helpful sidekick to the rehydration process, not a replacement. The typical dose studied in infant colic trials is a small liquid suspension given once daily, making it easy to administer. For parents, consistency is key: most studies show noticeable improvements emerging around the two-week mark. Beyond its primary uses in infants and young children, ongoing research is exploring its benefits for gut motility, constipation support, and even emerging connections to mood and gut-brain health — though these areas are still being studied. As always, if your baby is unwell or symptoms are severe, a conversation with your pediatrician is the best first step.