Ortho Biotic® R by Ortho Molecular Products

If you’re taking antibiotics and want to prevent loose stools, a Saccharomyces boulardii probiotic is one of the few with consistent human data. It’s useful for people with a history of antibiotic-associated diarrhea or prior C. difficile infection, frequent travelers, and those with a diarrhea-predominant pattern of irritable bowel symptoms. Because this is a yeast, not a bacteria, it keeps working during antibiotic courses. Stool testing isn’t required, but consider it if symptoms persist after 2 to 4 weeks.

S. boulardii is a probiotic yeast that isn’t killed by antibiotics. It crowds out harmful microbes, binds bacterial toxins from C. difficile, and raises secretory IgA (the antibody that coats your gut lining) to strengthen barrier function. The companion bacterial strains in this probiotic add diversity, which can help settle stool frequency and improve stool form within days to a few weeks. It does not permanently colonize, so benefits depend on continued use during the trigger period.

Take 1 capsule daily, with or without food. During antibiotics, take this probiotic at a different time of day, ideally 2 to 3 hours apart, and continue for 1 to 2 weeks after finishing the prescription. For travel, start 3 to 5 days before departure and continue through the trip. If you’re sensitive, begin every other day for the first week, then advance as tolerated.

Avoid S. boulardii if you are on antifungals like fluconazole or nystatin, which inactivate this probiotic. Use only with clinician oversight if you’re severely immunocompromised, critically ill, have a central venous catheter, or a history of fungemia. Yeast allergy is a contraindication. Pregnancy and breastfeeding data are limited, so discuss with your obstetric clinician before use.