Probiotics are live bacteria or yeasts taken to support digestive health. For most healthy people they are well tolerated, and the effects that do occur are usually mild, early and temporary.
Common side effects reported with this supplement or ingredient
- Bloating and wind, most common in the first days. See probiotics causing bloating.
- Mild abdominal discomfort or cramping
- Looser stools, or occasionally constipation. See probiotics causing diarrhoea.
- Increased thirst with some yeast-based products
These usually settle within one to two weeks as the gut adjusts. Starting with a smaller amount and building up often avoids the worst of it. Effects that are worsening rather than settling after a couple of weeks are a reason to stop and reconsider the product.
Possible interactions with medicines, chronic conditions or pregnancy
- Antibiotics. Probiotics are often taken alongside a course, but spacing them a couple of hours apart is usually suggested so the antibiotic does not simply kill the probiotic.
- Medicines that suppress the immune system, where live organisms need more caution.
- Antifungal medicines, which may act against yeast-based probiotics.
Probiotics are generally considered suitable in pregnancy, but check the specific product.
Who should speak to a healthcare professional before using it?
Probiotics are live organisms, and in a small number of situations that matters. Speak to a doctor first if you:
- Have a weakened immune system, from illness or from treatment such as chemotherapy or immunosuppressants
- Are seriously unwell or in hospital, particularly with a central venous line
- Have had bowel surgery, or have a condition affecting the gut wall
- Are caring for a premature or very young infant
In these groups, invasive infection from probiotic organisms has been reported. It is rare, and it is not a concern for the general population, but it is the reason probiotics are not a blanket recommendation.
Dose, product-quality and stacking risks
Supplements in South Africa are regulated as complementary medicines, and the checks applied are not the same as those for prescription medicines. Strength, purity and labelling can vary between products. See how supplements are regulated in South Africa and how to check supplement labels.
Probiotic products differ in which strains they contain and how many organisms survive to the end of shelf life. Different strains do different things, so a product that helped someone else may not suit your situation. Storage matters too, as some require refrigeration to remain viable.
When to stop and get medical advice
Stop and seek advice for fever, severe abdominal pain, blood in the stool, or symptoms that worsen rather than settle. Persistent digestive symptoms deserve a diagnosis rather than an indefinite supplement, particularly if there is weight loss or bleeding.
Related supplement safety guides
- Supplement side effects
- Supplement and medicine interactions
- When to see a doctor about a supplement
- Unsafe supplements in South Africa
- Report a supplement side effect in South Africa
See also gut health supplement side effects and digestive supplement side effects.
Medical Disclaimer: This content is for informational and educational purposes only and does not constitute medical diagnosis, prescription, or professional advice. Always read the patient information leaflet and consult a qualified doctor or pharmacist regarding any medicine or health concern.