Two Infant Formulas Under Scrutiny After Botulism Outbreak: Latest FDA Findings

The United States Food and Drug Administration (FDA) has released the results of its latest investigation into an infant botulism outbreak that was linked to ByHeart and Nara Organics infant formulas. The authority found the presence of Clostridium botulinum bacteria in one of the powdered milk raw materials, but has so far been unable to determine the primary source that triggered the outbreak. Botulism is a rare but potentially fatal disease that attacks the nervous system. It is caused by toxins produced by the Clostridium botulinum bacteria, which can trigger muscle paralysis leading to respiratory failure. The FDA noted that the outbreak, which lasted from late 2025 to early 2026, was officially declared over on 26 February 2026. During that period, 48 infants across 17 US states were reported infected. During the investigation, the FDA conducted direct inspections of ByHeart’s production facilities and one of its raw material suppliers. The probe was launched after a 2023 FDA inspection report resurfaced during the outbreak. At that time, the FDA found several food safety and hygiene violations at a ByHeart facility that has since been closed. The company also received a warning letter from the FDA in the same year. However, based on the latest investigation, the FDA stated it found no evidence that those violations contributed to the 2025-2026 botulism outbreak. Both the FDA and ByHeart did find Clostridium botulinum in one batch of powdered milk raw material. Nonetheless, no other factors were identified that could explain how the contamination led to the outbreak. The FDA also inspected Dairy Farmers of America, the milk processor for Organic West Milk, which is one of ByHeart’s suppliers. Whole Genome Sequencing (WGS) analysis showed that the Clostridium botulinum bacteria found in two samples from one batch of organic milk powder were identical to the bacteria found in clinical samples from sick infants and in finished infant formula products that tested positive. Despite this, the FDA is continuing its root cause analysis, particularly regarding the raw materials used in the production process. As a follow-up, ByHeart has drafted an action plan to strengthen food safety systems across its entire production process. The company will implement a new testing method for Clostridium botulinum with a higher level of sensitivity. The protocol was developed in collaboration with an independent laboratory. Testing will be conducted on all raw milk materials and every batch of finished product before it is marketed. Additionally, ByHeart will expand supplier audits, increase the frequency of raw material testing, implement a QR code-based batch tracking system, and establish an independent Food Safety Advisory Board. The FDA is also preparing several preventive measures to avoid similar incidents. These include increasing surveillance sampling to determine how often Clostridium botulinum is found in powdered milk. The agency also aims to deepen understanding of the risks posed by this bacterium in infant formula and to develop best practices for industry production processes. The FDA is further encouraging the Joint FAO/WHO Expert Meetings on Microbiological Risk Assessment (JEMRA) to conduct a risk assessment of spore-forming bacteria, including Clostridium botulinum and Bacillus cereus, in powdered infant formula. Additionally, the FDA supports a request from the Codex Committee on Food Hygiene for JEMRA to update the risk assessment for Cronobacter and Salmonella in powdered infant formula, while also developing stricter control recommendations covering production, packaging, and preparation.