
In just seven months, we have had two outbreaks of infant botulism tied to powdered formula made with whole milk powder. First ByHeart in November 2025 — 48 sick babies in 17 states. Then Nara Organics in June 2026 — three more hospitalized in California, Pennsylvania, and Washington. With ByHeart, DNA testing matched the exact strain of bacteria in the milk powder to the finished formula and to the sick infants. With Nara, the link so far is the epidemiology — the same kind of whole milk powder, the same rare illness, in babies who drank it — and testing of leftover formula is still underway. Either way, that is not a coincidence. That is a pattern.
I represent families in ByHeart, so I have a side. But the science here is not a matter of opinion, and the more I have looked at it, the more it troubles me. Here is what every parent should understand.
What happened
Both outbreaks involve organic whole milk powder. In the ByHeart outbreak, investigators confirmed the link the strongest way possible — by matching the exact strain of Clostridium botulinum found in the milk powder, in the finished formula, and in the sick babies. In the Nara outbreak, the link is so far epidemiologic: three infants who consumed the formula developed the same type A botulism, and FDA recommended the recall based on the severity of the illnesses and that signal while testing continues. ByHeart recalled all of its products in November 2025. Nara recalled all of its lots in June 2026. Thankfully, no babies died, but all were hospitalized and treated with BabyBIG, the special antitoxin used for infant botulism.
This kind of thing used to be vanishingly rare. For decades, infant botulism was believed to be mostly linked to honey and one-off exposures — not to a product sold in cans on store shelves. Two outbreaks in seven months, both involving whole milk powder, tells me the risk is either growing or has been going undetected all along. Neither answer is comforting.
Why milk powder, and why heat won’t fix it
The key thing to understand is that the bacteria behind botulism form spores — think of them as armored survival pods. Spores are built to withstand drying, time, and heat. And that is where the trouble starts.
Pasteurization kills ordinary bacteria, but it does not kill these spores. Neither does the spray-drying used to turn milk into powder. To reliably destroy botulism spores, you need the kind of intense, pressurized heat used in canning — heat that would scorch milk powder and strip out its nutrients. There is simply no way to apply it to powder without ruining the product. On top of that, fat appears to shield spores from heat even better, which may be one reason whole milk powder keeps showing up rather than nonfat. Bottom line: heat cannot be the safety net here.
Why not just sterilize the formula?
The answer is that we already do sterilize one kind — just not powder.
Ready-to-feed liquid formula is sterile. It is sealed and heat-treated by the manufacturer at temperatures high enough to kill these spores, and FDA says it is the safer choice for higher-risk infants. That is why hospitals reach for liquid in the NICU. Powder is different. You cannot apply that same sterilizing heat to powder without destroying its nutrition and taste, and drying actually makes spores even harder to kill. FDA has said it plainly: powdered formula is not a sterile product.
The catch is cost and access. Liquid runs two to three times the price of powder and does not store or ship as easily. Banning powder is not a realistic answer — the 2022 formula shortage showed how fragile the supply already is. So, the goal is not to get rid of powder. The goal is to make it safer and to be honest with parents about the risk.
The part that worries me most
Parents are told powdered formula is safe “if prepared properly,” which means mixing it with hot water at about 160°F. That advice is real, and it matters — but it was written to kill other germs, like Cronobacter and Salmonella. It does nothing to botulism spores. The spores survive that temperature easily.
Read that again. Parents were told that if they prepared the formula correctly, it was safe. But preparing it correctly gives no protection against the very spores that sickened these babies. The only genuinely protected option on the shelf is ready-to-feed sterile liquid.
What can actually be done
If heat can’t be the safety net, then prevention has to come from several directions at once:
- Cleaner milk at the source. These spores come from soil and the farm environment, and good udder hygiene at milking measurably reduces them. Formula makers can audit their dairy suppliers and test the milk coming in.
- Filtering before drying. Heat can’t kill the spores, but physical methods — the same ones cheesemakers use — can strip many of the spores out before the milk is dried into powder.
- Real testing, including DNA testing. Right now, no rule requires testing infant formula for botulism. DNA testing of ingredients and finished powder is the one tool that found the contamination in ByHeart — and that, used routinely, could catch this kind of problem before a single baby gets sick.
And here is something I have been saying loudly for a while. The very testing that would catch these outbreaks is the testing some defense lawyers quietly tell companies not to do — because if you find a problem, it becomes evidence. In other words: don’t look. I understand the logic, and I reject it completely. A company that chooses not to test so it can claim ignorance is choosing to keep selling a product it has decided not to check. Not looking is not a defense. It is the problem.
The good news: international food-safety regulators have finally started a formal review of botulism risk in powdered formula, and FDA is now testing powdered milk on its own. That is overdue — but it only matters if industry follows through and regulators enforce it. Of note, the U.S. has been stepping away from international health organizations – to its peril I would add – but I will leave that to another blog post.
The bottom line
Botulism spores are everywhere in the environment. They reach milk through the farm, survive pasteurization and drying, and can grow and produce toxin once formula is mixed up in a bottle. Powder cannot be sterilized without ruining it, and the safety advice parents are given was never designed to stop these spores. Heat is not the answer.
What is the answer is cleaner milk, better filtering, honest testing — including DNA testing — and straight talk with parents about why ready-to-feed sterile formula is the safer choice for the most vulnerable babies.
For the families I represent, and for me, the point is simple. In ByHeart, the contamination was in the powder the whole time, and the testing that would have caught it before babies were hurt was not being done. After two outbreaks in seven months, routine testing of dairy ingredients and finished powder — including DNA testing — is no longer optional.
These outbreaks were preventable. And if industry won’t fix it, the courts and the regulators will.
Sources
- FDA, Outbreak Investigation of Infant Botulism: Infant Formula (November 2025) — ByHeart. https://www.fda.gov/food/outbreaks-foodborne-illness/outbreak-investigation-infant-botulism-infant-formula-november-2025
- FDA, Post-Outbreak Response Activities: Clostridium botulinum Illnesses Associated with Consumption of Powdered Infant Formula — final ByHeart summary (48 infants, 17 states; outbreak declared over February 26, 2026). https://www.fda.gov/food/outbreaks-foodborne-illness/post-outbreak-response-activities-clostridium-botulinum-illnesses-associated-consumption-powdered
- FDA, Outbreak Investigation of Infant Botulism: Powdered Infant Formula (June 2026) — Nara Organics. https://www.fda.gov/food/outbreaks-foodborne-illness/outbreak-investigation-infant-botulism-powdered-infant-formula-june-2026
- CDC, Investigation Update: Infant Botulism Outbreak Linked to Infant Formula, November 2025. https://www.cdc.gov/botulism/outbreaks-investigations/infant-formula-nov-2025/investigation.html
- CDC Newsroom, Outbreak Update: Infant Botulism Linked to Powdered Infant Formula (June 13, 2026). https://www.cdc.gov/media/releases/2026/infant-botulism-outbreak-linked-to-powdered-infant-formula-june-2026.html
- FDA, Handling Infant Formula Safely: What You Need to Know; and FDA/WHO guidance on reconstituting powdered formula with water at about 160°F (70°C), a step aimed at Cronobacter and Salmonella — not botulism spores.
- Health Canada, Preparing and Handling Powdered Infant Formula — recommends commercially sterile liquid formula for premature, low-birth-weight, or immunocompromised infants.
- Molin, N. & Snygg, B.G. (1967). Effect of Lipid Materials on Heat Resistance of Bacterial Spores. Applied Microbiology, 15(6):1422–1426 — spores survive heat better in fat than in buffer.
- Burtscher, J., Rudavsky, T., Zitz, U., Neubauer, V. & Domig, K.J. (2023). Importance of Pre-Milking Udder Hygiene to Reduce Transfer of Clostridial Spores from Teat Skin to Raw Milk. Microorganisms, 11(5):1337.
- Codex Committee on Food Hygiene / Joint FAO–WHO Expert Meeting on Microbiological Risk Assessment (JEMRA): review of spore-forming pathogens, including C. botulinum, in powdered infant formula (2025–2026).












