Bifidobacterium infantis is a probiotic bacterium that has been studied for its potential benefits in managing symptoms of Irritable Bowel Syndrome (IBS). The scientific validation for its use comes primarily from several randomized, double-blind, placebo-controlled clinical trials. Notably, a landmark study by Whorwell et al. (2006) demonstrated that the specific strain Bifidobacterium infantis 35624, when administered daily, significantly improved several IBS symptoms—including abdominal pain, bloating, and irregular bowel movements—compared to placebo. These benefits were observed regardless of IBS subtype (constipation-predominant, diarrhea-predominant, or mixed).

The proposed mechanisms by which B. infantis may exert its effects include modulation of gut microbiota, reduction of pro-inflammatory cytokines, and restoration of intestinal barrier function. Additional studies and meta-analyses have generally supported mild to moderate efficacy, though some have reported mixed results, possibly due to differences in probiotic strains, dosages, and study populations.

While B. infantis is not universally effective for all IBS patients, and no probiotic is currently considered a cure, there is a moderate level of scientific evidence supporting its use as an adjunctive therapy to help manage IBS symptoms. Its inclusion in clinical guidelines for IBS management by some gastroenterological organizations reflects this evidence base.