Lactobacillus is a genus of probiotic bacteria that has been investigated for its potential to support or treat Inflammatory Bowel Disorders (IBD), including ulcerative colitis and Crohn’s disease. The scientific rationale centers on its ability to modulate the gut microbiota, enhance intestinal barrier function, and influence immune responses. Several randomized controlled trials and meta-analyses have assessed various Lactobacillus strains, often as part of multi-strain probiotic formulations, with mixed results.

Evidence is strongest for certain formulations in ulcerative colitis. For example, the use of multi-strain probiotics containing Lactobacillus (such as VSL#3) has shown some efficacy in inducing and maintaining remission in mild-to-moderate ulcerative colitis, as well as in preventing pouchitis after surgery. The data for Crohn’s disease is less robust, with most studies failing to show a significant benefit over placebo. The variability in results is attributed to differences in strains, dosages, study designs, and patient populations.

Major gastroenterological guidelines acknowledge that probiotics, particularly those containing Lactobacillus, may be considered as adjunct therapy in ulcerative colitis, though they are not first-line treatments and are not universally recommended for Crohn’s disease. Overall, the scientific evidence supports a modest benefit in specific contexts, but does not yet justify routine use for all IBD patients.