In recent months, the United States has faced a concerning outbreak of infant botulism linked to powdered infant formula produced by the premium brand ByHeart. Between August and November 2025, at least 23 infants across 13 states—including Arizona, California, Illinois, Kentucky, Michigan, Minnesota, New Jersey, North Carolina, Oregon, Pennsylvania, Rhode Island, Texas, and Washington—have been diagnosed with this serious bacterial infection. The outbreak has prompted ByHeart to voluntarily recall all its powdered infant formula products as of November 11, 2025, while health authorities continue to investigate the scope and source of contamination.
Botulism, a relatively rare but potentially life-threatening illness, is caused by the bacterium Clostridium botulinum. This bacterium produces neurotoxins that attack the nervous system, leading to paralysis. The CDC reported 243 laboratory-confirmed botulism cases in the U.S. in 2021, with infants accounting for 181 of these infections. Although the fatality rate ranges from 5 to 10 percent, the disease demands urgent medical attention, particularly in infants who are most vulnerable.
Infant botulism typically presents with early symptoms such as constipation, followed by progressive paralysis. Affected babies may lose control over facial muscles, leading to diminished facial expressions, drooling, difficulty feeding, and a weakened cry. Paralysis usually starts with a loss of head control, then progresses to the limbs, and in severe cases, can impair respiratory muscles, necessitating assisted breathing. The clinical diagnosis is challenging and may take up to a week, as it relies on stool sample analysis. Therefore, infants suspected of having botulism require immediate and close medical supervision.
Treatment involves hospitalization, where infants may be fed through tubes and, in severe cases, placed on ventilators. Doctors administer antitoxins to neutralize circulating toxins, but nerve regeneration and recovery can take weeks or months. Some infants may require additional therapies for feeding or speech after discharge. While survivors typically do not suffer long-term neurological damage, the illness and treatment period can be highly stressful and taxing for both infants and their families.
All 23 infants affected in this outbreak are currently hospitalized, though thankfully, no deaths have been reported so far. Most of these infants are under seven months old. The Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) are actively investigating the outbreak, working closely with ByHeart and other experts to identify how the contamination occurred and to prevent further infections.
ByHeart’s co-founder and president, Mia Funt, has expressed the company’s commitment to infant health and cooperation with regulatory authorities. In a statement to Scientific American, Funt extended sympathy to the families affected and emphasized the company’s focus on safety and transparency throughout the recall process.
Experts warn parents and caregivers to check their pantries for any ByHeart powdered infant formula and to avoid using it. Barbara Kowalcyk, director of the Institute for Food Safety and Nutrition Security at George Washington University, cautions that voluntary recalls might be overlooked or underestimated by some consumers, increasing the risk that contaminated formula remains in homes. She also anticipates that additional cases linked to the outbreak may surface in the coming weeks.
Powdered infant formula is not a sterile product and has been previously associated with bacterial contamination, including botulism and other pathogens. Clostridium botulinum exists in the environment primarily as hardy spores that can survive for long periods. While industrial processes involving high heat or pressure can eliminate these spores, typical home heating or preparation methods do not reliably kill them, allowing spores to persist in formula products.
The Infant Botulism Treatment and Prevention Program reports that since August 2025, 84 infants have received treatment for botulism in the U.S., with 36 cases linked to powdered infant formula exposure. Investigations are ongoing to determine whether contamination occurred during manufacturing, distribution, or possibly in consumers’ homes. The California Department of Public Health found C. botulinum in an opened can of ByHeart formula and is now testing unopened products for contamination.
In an open letter to the FDA, ByHeart mentioned a broader “unprecedented spike” in infant botulism cases nationally, which some experts suggest may reflect wider trends in foodborne illnesses or changes in environmental factors. This outbreak highlights ongoing challenges in food safety surveillance and the need for vigilance in monitoring even low-moisture foods like powdered formula, which were historically considered