Saccharomyces boulardii is a non-pathogenic probiotic yeast that may protect against antibiotic-associated diarrhoea caused by a disruption in the balance of healthy gut flora. It is resistant to local stresses, including digestive enzymes, bile salts, organic acids, and variations in temperature and pH. As Saccharomyces boulardii may also naturally resistant to antibiotics, it can be taken by individuals receiving antibiotics to nutritionally support the gastrointestinal tract by maintaining gut flora balance.