Sacro-B 250 mg by Thorne

Travel coming up or starting an antibiotic? Saccharomyces boulardii, a probiotic yeast, is one of the few probiotics with solid data for antibiotic-associated diarrhea. It’s a fit if you’ve had loose stools on antibiotics before, are prone to traveler’s diarrhea, or are recovering from C. difficile infection alongside standard therapy. Expect steadier stools within a few days. This is prevention and short-course support, not a daily forever probiotic for most people.

Unlike bacterial probiotics, this yeast isn’t killed by antibiotics, so you can use it during a prescription. It blocks harmful microbes from sticking to the gut lining, breaks down certain toxins from C. difficile, and increases secretory IgA (the antibody that patrols your gut mucus). The result is fewer watery stools and quicker recovery when the gut is under stress.

Take one capsule between meals, one to three times daily. For antibiotics, twice daily starting with the first dose and continue 3–5 days after you finish. For travel, begin 2–3 days before departure and continue during the trip. Hydration matters: use oral rehydration salts if diarrhea is significant. You don’t need to separate it from antibiotics; this yeast is unaffected.

Skip Saccharomyces boulardii if you’re on antifungal drugs like fluconazole or nystatin, which inactivate it. Avoid if you’re severely immunocompromised, critically ill, or have a central venous line due to rare bloodstream yeast infections reported in hospitals. If you have a yeast allergy, choose a bacterial probiotic instead. Mild gas can occur the first few days and usually settles.