Lactobacillus kefiri is a probiotic bacterium commonly found in kefir, a fermented milk drink. Its use in supporting or treating Inflammatory Bowel Disorders (IBD), such as Crohn’s disease and ulcerative colitis, is based on emerging but limited scientific evidence. Several in vitro studies and animal models have demonstrated that L. kefiri can modulate the gut microbiota, enhance mucosal barrier function, and reduce intestinal inflammation by modulating cytokine production, notably decreasing pro-inflammatory cytokines and increasing anti-inflammatory ones (e.g., IL-10). In particular, a few small-scale studies and preclinical trials suggest that L. kefiri may suppress inflammation and support gut health, which are relevant to IBD pathology.

However, robust clinical evidence in humans is sparse. Most clinical studies on probiotics for IBD have focused on other strains (e.g., Escherichia coli Nissle 1917, Lactobacillus rhamnosus, Bifidobacterium species). The handful of studies specifically evaluating L. kefiri in humans are preliminary, often involving small sample sizes or open-label designs. Therefore, while there is scientific rationale and some supportive preclinical data, the evidence is not yet strong or conclusive enough to firmly recommend L. kefiri as a treatment for IBD. Larger, well-designed clinical trials are needed to validate its efficacy and safety in this context.