Can early-life herbicide exposure harm your baby's gut bacteria and brain development?

What's actually in it

Babies are exposed to herbicides through breast milk, formula mixed with tap water, and pureed fruits and vegetables. Common herbicides like glyphosate, atrazine, and 2,4-D are used on crops that end up in baby food and in water supplies. These chemicals are designed to kill plants, but they also affect the bacteria living in your baby's gut.

A baby's gut microbiome is still forming during the first year of life. Disruptions during this window can have lasting effects on immunity and brain development.

What the research says

A 2026 study in Ecotoxicol Environ Saf measured herbicide levels in hospitalized infants and analyzed their gut microbiota and neurobehavioral development. Infants with higher herbicide exposure had altered gut bacterial communities and different neurobehavioral scores.

The gut-brain connection played a central role. Herbicides disrupted specific bacterial species that produce neurotransmitters and anti-inflammatory compounds. When these bacteria are knocked back, the brain doesn't receive the chemical signals it needs for normal development.

Buying organic produce for baby food, using filtered water for mixing formula, and breastfeeding (which despite containing some contaminants, provides protective factors) all help minimize herbicide exposure during the critical first year.