Saccharomyces boulardii is a probiotic yeast that has been extensively studied for its role in supporting and treating various forms of enteritis, including antibiotic-associated diarrhea, infectious diarrhea, and inflammatory bowel conditions. Multiple randomized controlled trials and meta-analyses have demonstrated that S. boulardii can reduce the duration and severity of acute infectious diarrhea, especially in children. Studies also show its efficacy in preventing and treating Clostridioides difficile-associated diarrhea and recurrent infections, a common form of antibiotic-associated enteritis. The mechanisms attributed to S. boulardii's effectiveness include inhibition of pathogenic bacteria, modulation of the host's immune response, reinforcement of the gut barrier, production of proteases that neutralize bacterial toxins, and restoration of normal gut flora disrupted during enteritis.

Systematic reviews published in reputable journals such as The Cochrane Database of Systematic Reviews and Alimentary Pharmacology & Therapeutics support its use, particularly for pediatric acute gastroenteritis and prevention of antibiotic-associated diarrhea. Clinical guidelines in some countries recommend S. boulardii as an adjunctive therapy for these conditions. While efficacy may vary depending on the cause and severity of enteritis, and not all studies show uniform results, the overall body of evidence provides substantial scientific validation for its use. The safety profile of S. boulardii is generally favorable, although caution is warranted in immunocompromised patients.