Can maternal microplastic exposure affect baby gut and immune development in animal research?
In animal research, yes. A 2026 mouse study found maternal polystyrene microplastic exposure changed milk microbes, offspring gut colonization, and immune markers.
What is actually in it
Polystyrene microplastics are tiny plastic particles. They can come from plastic wear, packaging, dust, and other plastic contact.
During pregnancy and breastfeeding, researchers are studying whether maternal microplastic exposure can affect milk microbes and a baby's early gut bacteria.
What the research says
A 2026 study in FASEB J exposed pregnant and lactating mice to polystyrene microplastics in drinking water at 10 mg/L and 40 mg/L.
The exposed offspring had disrupted early gut colonization. Beneficial bacteria such as Ligilactobacillus decreased, while Escherichia-Shigella increased.
The study also reported excessive weight gain, lower serum IL-6, fewer splenic T-cell proportions, and weaker intestinal barrier integrity in exposed offspring. The researchers linked these changes with altered milk microbiome structure and short-chain fatty acid concentrations.
This was a mouse study, not proof that one normal plastic exposure harms a baby. Breastfeeding still has major benefits. A practical step is to reduce avoidable plastic food contact at home, especially with hot food. Glass storage is one simple swap.