Probiotic Contamination, Mislabeling and Recall Reports

Urgent first

If a person who is immunocompromised, has a central line, or is a premature or very young infant develops fever, vomiting, bloody stools or seems seriously unwell after taking a probiotic, get urgent medical care; the NHS lists bloody diarrhoea and worry about a baby under 12 months among reasons for urgent advice. [1] In the US, call 911 in an emergency. If someone swallowed too much of any supplement, Poison Help is 1-800-222-1222 (US). Whether a premature infant receives any probiotic is a decision for the hospital team: the FDA warns that preterm infants given probiotics are at risk of invasive, potentially fatal disease. [2]

The short answer

Most laboratory studies find that many products match their labels, but some do not: reports include live counts below the label, wrong or missing species, extra strains, and, in rare documented cases, a harmful contaminant or a recall. This page describes what the sources found. It names no products, and the studies are snapshots that cannot rank or clear any product.

Evidence labels used here: mixed, evidence of harm (documented case), and Proper evidence not found.

What health bodies say

• NCCIH (US) says some probiotic products have been reported to contain microorganisms other than those on the label, and in some instances these contaminants may pose serious health risks. [3]
• The NHS (UK) says probiotics are generally classed as food rather than medicine, so we cannot always be sure a product contains the bacteria stated on the label. [4]
• In its 2023 statement on preterm infants, the FDA (US) said unapproved probiotic products have not been evaluated for compliance with its manufacturing and testing standards for drugs, including testing for other organisms. [5]

A documented contamination case

In 2014 a hospital in Connecticut reported a fatal gastrointestinal mucormycosis (a rare mould infection) in a preterm infant who had received a probiotic dietary supplement powder for 7 days. Unopened containers from the same lot grew Rhizopus mould, which CDC confirmed as Rhizopus oryzae, the same species found in the infant's tissue. The manufacturer recalled several lots, and CDC found no additional infant cases. [6]

Recall notices in Health Canada's database

We read three Health Canada recall notices for probiotic capsules. We did not do a complete search of recall databases, so this is not a full list. We do not name the products.

Each notice tells people to verify whether their product is affected, to consult a health care provider before discontinuing use or with concerns, and to report side effects to Health Canada. [9][8][7] For the FDA, we found one 2023 statement that a probiotic product sold for preterm infants had been voluntarily recalled; we did not read the recall notice itself. [5] Proper evidence not found: a US recall list for probiotics from the FDA, which we did not search.

What laboratory studies of marketed products found

The samples, countries and methods differ, so results are not comparable across studies. Several used sequencing, which detects DNA but does not by itself show a living contaminant.

What this does and does not mean

An accurate label does not show that a strain works; a recalled lot says nothing about other lots or products. For people at higher risk of infection, label problems matter more because the product contains live organisms. The NCCIH advises consulting a health care provider before a probiotic supplement. [3] Practical steps that follow from the sources: check the product against recall notices from the regulator where you live, keep the lot number, and report side effects (see side effects and reporting). For how testing marks are described see quality testing and certifications, and for a longer lab-study review see label accuracy and third-party testing. To read a label see how to read a probiotic label. For serious infections linked to probiotics see probiotics and bloodstream infection.