What are probiotics?
Probiotics are "live microorganisms that, when administered in adequate amounts, confer a health benefit on the host" (Hill et al., 2014). Most are bacteria, but the yeast Saccharomyces boulardii counts too. The fibers that feed them are prebiotics; products combining both are synbiotics.
What do probiotics actually help with?
The strongest evidence is for preventing antibiotic-associated diarrhea and C. difficile diarrhea (Goldenberg et al., 2017, Cochrane review). Some strains may ease IBS symptoms or shorten acute infectious diarrhea in kids, but results are mixed. Claims about immunity, weight loss and skin are mostly unproven. Note that in the US, probiotics are sold as dietary supplements and aren't FDA-approved to treat disease.
How to choose a probiotic
Look for the full strain name (e.g., Lactobacillus rhamnosus GG) matched to research for your goal, and a CFU count guaranteed through the expiration date. Take it at least two hours apart from antibiotics. Mild gas or bloating early on is common. People who are severely immunocompromised should ask a doctor first because of rare bloodstream infections. See also gut microbiome.
This article is general health information and is not a substitute for diagnosis or treatment. If symptoms persist, see a doctor.
FAQ
- Should I take probiotics on an empty stomach?
- It depends on the strain and capsule. Following the label and taking it consistently matters more than timing.
- Is yogurt enough?
- Yogurt and kefir contain live cultures, but strains and amounts vary. For a specific benefit, choose a studied strain.
Sources reviewed: 2026-10-25
References
- Hill, C., Guarner, F., Reid, G., et al. (2014). The International Scientific Association for Probiotics and Prebiotics consensus statement on the scope and appropriate use of the term probiotic. Nature Reviews Gastroenterology & Hepatology, 11(8), 506–514.
- Goldenberg, J. Z., Yap, C., Lytvyn, L., et al. (2017). Probiotics for the prevention of Clostridium difficile-associated diarrhea in adults and children. Cochrane Database of Systematic Reviews, CD006095.