Botulism Probe Expands to 51 Infant Cases Tied to ByHeart Formula

Federal health officials have expanded an investigation into a botulism outbreak linked to ByHeart infant formula, now encompassing 51 cases among infants in 19 states since the product's launch in March 2022. The U.S. Centers for Disease Control and Prevention and the Food and Drug Administration announced the broader scope on Wednesday, warning that contamination with Clostridium botulinum bacteria may have affected all ByHeart Whole Nutrition formula produced to date.

The outbreak, first publicly identified in November, initially focused on 39 suspected or confirmed cases reported since August in 18 states. With the updated case definition, which includes any infant botulism linked to ByHeart exposure since production began, officials added 12 more illnesses. These span from December 2023 to July 2025, with the most recent onset on December 1. All 51 affected infants, ranging in age from 16 to 264 days old, required hospitalization, but no deaths have occurred. Epidemiologic interviews confirmed that every infant consumed the powdered formula in the month before falling ill.

ByHeart, a New York-based company founded in 2016 that holds about 1 percent of the U.S. infant...