kefir (St. Luke's Duluth)

Kefir is a fermented milk drink produced by the action of kefir grains, which consist of a symbiotic culture of lactic acid bacteria and yeasts. It is a probiotic-rich food used in clinical settings to modulate the gastrointestinal microbiota. In the context of clinical research, kefir is being evaluated for its potential to prevent antibiotic-associated diarrhea (AAD) and *Clostridium difficile* infection (CDI) in patients undergoing systemic antibiotic treatment. The therapeutic effect is attributed to the restoration of healthy gut flora, competitive exclusion of pathogenic organisms, production of antimicrobial metabolites (such as organic acids and bacteriocins), and modulation of the host immune response.