Educational information, not medical advice. Supplements can interact with medications and medical conditions. Consult a clinician before starting probiotics or prebiotics, especially if you are pregnant, breastfeeding, immunocompromised, have a central venous catheter, have recently had surgery, or take immunosuppressants. Some links are affiliate links - we earn a commission if you purchase, at no cost to you.

Probiotics by Condition

Updated June 2026 · Sources: Cochrane, ESPGHAN, NICE, Monash University, NIH ODS

Probiotics are not interchangeable. A strain with strong evidence for antibiotic-associated diarrhoea may have none for IBS, and vice versa. These guides start from the condition and work back to the specific strains and fibres that have trial support for it - graded honestly, with the gaps named rather than glossed over. Each one separates what the evidence supports from what is merely marketed.

For how we assign evidence tiers, see our evidence methodology page. For a strain-first view, see the strains guide.

Condition Guides

Post-Antibiotic Recovery

Strong Evidence

What to take alongside antibiotics and for how long. S. boulardii (taken from day 1, unaffected by antibiotics) and L. rhamnosus GG have the strongest evidence for preventing antibiotic-associated diarrhoea.

Irritable Bowel Syndrome (IBS)

Emerging Evidence

Strain choice matched to Rome IV subtypes (IBS-C, IBS-D, IBS-M). B. infantis 35624 and L. plantarum 299v have the best IBS-specific evidence; high-FODMAP prebiotics can make symptoms worse.

Constipation

Strong Evidence

Psyllium husk is the evidence-based first-line supplement; B. lactis BB-12 and L. reuteri DSM 17938 have the strongest probiotic-specific evidence for stool frequency and consistency.

Related

Probiotic Strains GuidePrebiotic FoodsProbiotic FoodsProbiotic vs Prebiotic Comparison

Updated 2026-04-27