Following Infant Formula Incidents, FDA Urges Manufacturers to Implement Stronger, Substantive Supplier Oversight
Following three recent, high-profile public health incidents involving infant formula, in which hazards were introduced to final products through contaminated ingredients, the U.S. Food and Drug Administration (FDA) has sent a letter to the infant formula industry and its suppliers to call for increased vigilance to ensure food safety.
Recent events that demonstrated the critical importance of robust supplier management include the two infant botulism outbreaks associated with formula produced by ByHeart Inc. and Nara Organics Inc., and the global recall of infant formula products from multiple brands due to cereulide contamination.
Alongside the letter to industry, FDA also discussed initial findings from surveillance of Clostridium botulinum in powdered milk initiated in response to the ByHeart outbreak.
Clostridia in Powdered Milk
Infant Formulas Behind Botulism Outbreak Shared Supplier
The outbreak linked to ByHeart formula ended in February 2026 with 48 babies sickened in 17 states, while the Nara Outbreak, which is still ongoing, now includes four illnesses in three states. For a period of time in 2025, ByHeart and Nara Organics both used organic whole milk supplied by Organic West Milk and dried at a Dairy Farmers of America (DFA) processing facility.
FDA has not yet determined if this ingredient supply chain is the source or route of contamination in these outbreaks, although testing and analysis conducted during the agency’s investigation into the ByHeart outbreak did reveal the presence of C. botulinum in a powdered milk ingredient, and also matched C. botulinum isolates recovered from a DFA facility to isolates from a clinical case and a finished formula product sample. The agency is continuing to investigate the root causes of the two infant botulism outbreaks.
Supplier Information-Sharing Failure
Additionally, in response to the ByHeart outbreak and before the Nara Organics outbreak emerged, FDA conducted a trace-forward investigation to determine if Organic West Milk had supplied milk to any powdered infant formula manufacturers other than ByHeart. At that time, Organic West Milk provided an incomplete customer list, failing to indicate that its milk was supplied to manufacturers of Nara Organics infant formula.
Results of FDA Surveillance of C. botulinum in Powdered Milk
Prompted by the ByHeart and Nara Organics infant formula incidents, FDA has completed initial surveillance to better understand the prevalence of C. botulinum in powdered milk. The former Commissioner for Human Foods Kyle Diamantas, J.D. previously said this surveillance will inform whether C. botulinum contamination is a foreseeable hazard for which companies could test.
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In the initial sampling assignment conducted in February 2026, FDA collected 48 powdered milk samples from four suppliers to infant formula manufacturers (12 samples per supplier). Of the 48 samples, 46 were negative by polymerase chain reaction (PCR) analysis and did not undergo any additional testing. The remaining two samples, both organic nonfat milk powder, tested positive by PCR and were further processed and analyzed using whole genome sequencing (WGS).
WGS confirmed the presence of C. sporogenes with a gene highly associated with botulinum toxin B1. FDA says this finding suggests—but does not confirm—that the bacterium could produce botulinum toxin in certain environmental conditions. Both sequences were nearly identical, and both samples were acquired at the same firm.
Cereulide Toxin in ARA Oil
Likewise, a multinational contamination event occurring in late 2025 through early 2026 resulted in nearly 150 suspected and confirmed cases of cereulide intoxication in babies across ten countries. Cereulide, a heat-stable toxin produced by Bacillus cereus, was introduced to the global supply chain via contaminated arachidonic acid (ARA) oil from a Chinese supplier used as an ingredient in infant formula produced by several brands, including Nestlé, Danone, Lactalis Nutrition Santé, and others. This prompted multiple global downstream recalls in 99 countries, and greater regulatory scrutiny of ARA oil and the implicated supplier by EU authorities.
FDA to Manufacturers: Know Your Suppliers
In its letter to the infant formula industry, FDA expressed its expectation that manufacturers exercise substantive oversight of their suppliers, including understanding where their ingredients come from, how they are produced, what risks they may carry, and whether those risks are effectively controlled. When a contaminated ingredient or supplier concern is identified, whether by FDA or through industry’s own monitoring, manufacturers are expected to act swiftly to assess and address the risk.
FDA also recommended that infant formula manufacturers and their supply chain partners stay abreast of applicable recall notifications, outbreak investigations, and import alerts, which may serve as important risk signals. The agency said that, based on experience, ignoring or downplaying these signals can lead to increased risks to infants and preventable public health events.
Relevant to FDA’s call for substantive supplier oversight: In a recent Food Safety Magazine cover feature, John Keogh, M.B.A., M.Sc., supply chain researcher and professor, explains the importance of “buyer-led screening” in light of the increasing regulatory expectation that companies placing products on the market be able to defend supplier decisions, and describes what effective buyer-led screening looks like.
FDA to Participate in Global Development of Best Practices
FDA acknowledged the uniquely challenging nature of managing risks related to spore-forming microbes in infant formula ingredients and recognized there might not be a single best approach for addressing them. For example, research prompted by recent events suggests that sulfite-reducing clostridia (SRC) enumeration, considered the current industry “gold standard” for Clostridia detection and which is recommended as a general indicator of spore contamination by the International Commission on Microbiological Specifications for Foods (ICMSF), may not be enough to prevent formula-associated botulism outbreaks. Testing specifically for C. botulinum can be inaccessible due to requiring highly secure laboratories and technical expertise.
The agency said it is prepared to work with industry to identify best practices and will continue to solicit advice from experts in academia and international scientific bodies, such as the Codex Committee on Food Hygiene (CCFH), which recently decided to initiate work on C. botulinum in infant formula, and ICMSF.
FDA has already supported CCFH's request for scientific advice from the Food and Agriculture Organization of the United Nations (FAO)/World Health Organization's (FAO/WHO's) Joint Expert Meeting on Microbiological Risk Assessment (JEMRA) related to C. botulinum and B. cereus in powdered infant formula. The agency has also asked ICMSF to consider revisiting its guidance on testing for C. botulinum in powdered infant formula and dairy-based ingredients for infant formula.
