ByHeart and Nara Organics Infant Botulism Outbreaks: What FDA Found

The short answer

FDA linked two U.S. infant botulism outbreaks to powdered formula: ByHeart (48 infants in 17 states, all hospitalized, no deaths; declared over February 26, 2026) and Nara Organics (4 confirmed cases in 3 states; declared over August 27, 2026) [1][2][3]. Both formulas used organic milk from the same supplier and the same spray-drying processor, and genome sequencing tied the outbreaks together [1]. FDA says the root cause is still under investigation [1]. All products from both brands were recalled [2][3].

This is a microbiological (bacterial spore) issue, not a heavy-metals one. For chemical contaminants in formula, see infant formula heavy metals: FDA vs Consumer Reports; for the separate nutrient-standards proposal, see FDA infant formula nutrient requirements 2026.

What happened in the ByHeart infant botulism outbreak?

From late 2025 into early 2026, FDA, CDC, and the California Department of Public Health's Infant Botulism Treatment and Prevention Program investigated a multistate outbreak among infants fed ByHeart Whole Nutrition powdered formula [1][2]. FDA's final case table lists 48 illnesses (28 confirmed, 20 probable), 48 hospitalizations, 0 deaths, and a last illness onset of November 29, 2025 [2].

ByHeart first recalled two lots, then on November 11, 2025 expanded the recall to all ByHeart formula nationwide, including cans and single-serve "anywhere pack" sticks [2]. On December 23, 2025, the company reported Clostridium botulinum in six of 36 finished-product samples from two batches already covered by the recall [2]. FDA also documented recalled cans remaining on shelves and sent warning letters to four major retailers on December 12, 2025 [2]. CDC declared the outbreak over on February 26, 2026 [1].

Outbreak	Illnesses	Hospitalized	Deaths	States	Declared over
ByHeart (2025–2026)	48 (28 confirmed, 20 probable) [2]	48 [2]	0 [2]	17 [2]	Feb 26, 2026 [1]
Nara Organics (2026)	4 confirmed [3]	4 [3]	0 [3]	3 (CA, PA, WA) [3]	Aug 27, 2026 [1][3]

How is the Nara Organics outbreak linked to ByHeart?

Genome sequencing and a shared supply chain connect them. FDA reports that one clinical sample from a Nara Organics case genetically matched a ByHeart case, a ByHeart formula-base sample, and four unopened ByHeart cans [1]. The implicated Nara lots were made with milk supplied by Organic West Milk and spray-dried by Dairy Farmers of America—the same suppliers in the ByHeart outbreak [1][3].

FDA says these findings "indicate that there is a common source of contamination between the two outbreaks," but that there is not yet enough evidence to determine where the milk was contaminated [1]. Nara Organics' formula was manufactured in Europe; on June 13, 2026 the company agreed to recall all of its Whole Milk Organic Powdered Infant Formula, which carried "Best By" dates ending in 2027 [3].

What did FDA find in the milk powder supply chain?

FDA's ByHeart facility inspections identified C. botulinum in a powdered milk ingredient but found no other factor in ByHeart's plants that explained the outbreak [1][2]. At Dairy Farmers of America, two samples from one lot of organic whole milk powder matched a clinical sample and a positive formula sample by whole genome sequencing [1]. That inspection also did not identify a cause, and FDA has not named a root cause [1].

FDA explains why spores are hard to control: non-spore-forming bacteria such as Cronobacter and Salmonella are susceptible to pasteurization, while spore-formers like C. botulinum can survive typical pasteurization, and testing for them can take two or more weeks [1].

What is FDA doing after the outbreaks?

FDA has moved to post-outbreak work focused on ingredients and prevention [1]:

• Surveillance sampling: in February 2026 FDA collected 48 powdered milk samples from four suppliers to formula makers; 46 were PCR-negative, and 2 organic nonfat milk powder samples carried Clostridium sporogenes with a gene highly associated with botulinum toxin B1. FDA confirmed that powder was not used to make infant formula and did not match prior outbreak sequences [1].
• Industry letter: on July 13, 2026 FDA wrote to formula makers about ingredient-sourcing risks and called for increased vigilance [1].
• Risk assessment requests: FDA advocated for a FAO/WHO (JEMRA) risk assessment on spore-forming pathogens in powdered formula and asked ICMSF to revisit its guidance on testing powdered formula and dairy ingredients for C. botulinum [1].
• Industry and academic work: engagement with Cornell University's Pathogenic Spore Consortium and review of a Reagan-Udall Foundation roundtable report released September 3, 2026 [1].

What symptoms does FDA tell parents to watch for?

FDA says most infants with infant botulism first develop constipation, poor feeding, loss of head control, and difficulty swallowing, which can progress to difficulty breathing; symptoms can take as long as several weeks to appear [2]. FDA's instruction is to seek immediate medical attention if an infant who consumed a recalled formula shows these signs, and to wash items and surfaces that touched the formula with hot soapy water or a dishwasher [2].

This is not medical advice. If you are worried about your baby, contact your pediatrician or emergency services rather than relying on any website, including this one.

What happens to ByHeart and the U.S. formula supply now?

ByHeart discontinued its formula after the outbreak [4]. Food Safety Magazine reported on November 5, 2026 that Perrigo agreed to sell its infant formula business for up to $175 million to MeridianMade, a new company formed by ByHeart's co-founders [4]. That report notes congressional questions about the deal [4]. Neither ByHeart nor Nara Organics is in our rankings.

FAQ

Is powdered infant formula safe to use now?

FDA's published actions focus on the recalled ByHeart and Nara Organics products, which should no longer be on sale, and on ingredient-level prevention [1][2][3]. If you have either brand at home, FDA says not to use it [2][3]. Ask your pediatrician about any specific formula choice.

Did the two outbreaks have the same cause?

FDA says matching genome sequences and shared milk suppliers point to a common source of contamination, but where the milk was contaminated has not been determined [1].

How long after feeding can symptoms appear?

FDA says symptoms of infant botulism can take as long as several weeks to develop after formula ingestion [2].

Is infant botulism related to heavy metals in formula?

No. Infant botulism comes from Clostridium botulinum spores and toxin [1]. Heavy metals are a separate chemical-contaminant issue; see our formula heavy-metals explainer and Closer to Zero roadmap 2026.

Does California AB 899 testing cover infant formula?

No. California's AB 899 baby-food testing law excludes infant formula [5]. See AB 899 public results vs lot-code lookups.

References

1. U.S. FDA, Post-Outbreak Response Activities: Clostridium botulinum Illnesses Associated with Consumption of Powdered Infant Formula (content current as of September 22, 2026).
2. U.S. FDA, Outbreak Investigation of Infant Botulism: Infant Formula (November 2025).
3. U.S. FDA, Outbreak Investigation of Infant Botulism: Powdered Infant Formula (June 2026).
4. Food Safety Magazine, ByHeart Formula Discontinued After Infant Botulism Outbreak, But Founders Set to Acquire Different Formula Business (November 5, 2026).
5. Consumer Reports, Best Baby Food Brands for Reporting Heavy Metals: California AB 899.