[Reading Science] Ultrafine Plastics Cause Obesity in Breastfed Children

Life Science Research Team Identifies Effects of Ultrafine Plastics Through Breastfeeding

A study has found that reducing exposure to ultrafine plastics, which cause environmental pollution, as much as possible during pregnancy or breastfeeding can help prevent obesity in children.

The process by which ultrafine plastics ingested by the mother induce weight gain in the offspring.

The Korea Research Institute of Bioscience and Biotechnology (KRIBB, President Jang-Sung Kim) announced on the 28th that a research team led by Dr. Da-Yong Lee from the Rare and Intractable Disease Research Center has identified that ultrafine plastics are transmitted to the next generation through breast milk, causing abnormal weight gain in offspring.

Using a mouse animal model, the research team revealed that ultrafine plastics induce changes in the components of maternal breast milk, and offspring consuming this milk experience abnormalities in lipid metabolites and alterations in gut microbiota, leading to abnormal overweight.

(Front row) First author Dr. Jihyeon Jeong, (back row from left) Principal investigator Dr. Dayong Lee, Corresponding author Dr. Songhee Cho of KRICT

According to the research team, breast milk exposed to polystyrene (PS) and polypropylene (PP) ultrafine plastics showed an increase in LPC (lysophosphatidylcholine), a lipid component highly associated with obesity, and a decrease in PC (phosphatidylcholine). Similar changes were observed in the blood of offspring that consumed this breast milk. Conversely, when the research team suppressed the lipid component changes caused by ultrafine plastics, the offspring's weight gain returned to normal.

Analysis of the gut microbiota of developing offspring fed breast milk from mothers exposed to ultrafine plastics also confirmed a significant decrease in bacterial species known to have anti-obesity effects compared to the control group (offspring of normal mothers).

Dr. Da-Yong Lee, the principal investigator, stated, “This is the first metabolic elucidation of the potential link between microplastics and childhood obesity.” He added, “In-depth follow-up studies and investigations are needed regarding the amount of microplastics exposure and biological effects in patients with related diseases.” Dr. Lee explained, “Newborns can also be exposed to ultrafine plastics through baby bottles. To maximize the benefits of breastfeeding, situations where exposure to ultrafine plastics can occur should be avoided as much as possible during pregnancy and breastfeeding.”

Ultrafine plastics are plastic particles formed by the breakdown of microplastics, with sizes less than 1 μm (micrometer, one-millionth of a meter), making them extremely small and almost impossible to observe or detect. Microplastics smaller than 5 mm are not filtered out during wastewater treatment processes and flow directly into rivers and oceans, causing environmental problems and adversely affecting humans who ingest them directly or indirectly.

Although microplastics have recently emerged as a social issue and many studies are being conducted on their impact on the environment and humans, research on the effects of microplastics on offspring across generations remains insufficient.

This study was published online on February 24 in Environment International (IF 11.8), a leading journal in the environmental field. (Paper title: Maternal nanoplastic ingestion induces an increase in offspring body weight through altered lipid species and microbiota / Corresponding authors: Dr. Da-Yong Lee, KRIBB; Dr. Seong-Hee Cho, Korea Research Institute of Chemical Technology / First author: Dr. Jeong Bo-Hyun, KRIBB)