Probiotics and Antibiotics: What to Know

Taking a probiotic during or after a course of antibiotics is among the most common reasons people buy one. Here is what can be said accurately, and where the question needs a pharmacist rather than a website.

Ask the pharmacist dispensing your antibiotic

That is the substantive advice on this page. Antibiotics differ, the reason you are taking one differs, and your circumstances differ. The person handing you the prescription can answer in a way a general article cannot, and it costs nothing to ask.

The spacing question

Antibiotics act on bacteria, including the organisms in a probiotic. Separating the two by a period of hours is the approach commonly described, on the straightforward reasoning that taking them together works against the probiotic. Product labels frequently give a specific interval — follow the one on your product.

What the evidence base looks like

This is an area with a substantial research literature and genuine disagreement within it. The NIH Office of Dietary Supplements and NCCIH both summarise the state of the evidence, including where findings are mixed and where they are strain-specific. Both are worth reading in the original rather than through a retailer’s summary, and neither reads like the confident claims on a typical product page.

Do not stop your antibiotic

Whatever you decide about a probiotic, complete the antibiotic course as prescribed unless your doctor tells you otherwise.

Who should not take probiotics without medical supervision

Probiotics are live organisms, and there are situations where introducing them is not appropriate:

• People who are severely immunocompromised, including during chemotherapy or after transplant
• People who are critically ill or in intensive care
• People with central venous catheters
• Premature infants
• People with severe acute pancreatitis

If any of these apply to you or the person you are buying for, this is a medical decision rather than a shopping one.

When to seek advice urgently

Severe or bloody diarrhoea during or after antibiotics, fever, or severe abdominal pain are reasons to contact a doctor rather than to buy a supplement.

This page is consumer information, not medical advice. Please read our medical disclaimer.

References

• NIH Office of Dietary Supplements — Probiotics (Health Professional Fact Sheet)
• NCCIH — Probiotics: What You Need To Know