Microplastic-associated gut microbial profile and antibiotic resistance in preschool children: a multicentre cross-sectional study in China.

Eight types of microplastics were detected in all 335 faecal samples collected from preschool children across three Chinese cities.

• Study was conducted in Xiamen, Shanghai, and Nanjing, China from October 2022 to March 2023
• A total of 335 couples of faecal samples were collected and analysed
• MPs were detected using Py-GC/MS (pyrolysis-gas chromatography/mass spectrometry)
• The median concentration of MPs was 212.1 μg/g dw (dry weight)
• Eight distinct types of MP polymers were identified across the samples

Microplastic exposure was associated with alterations in the composition of the gut microbiota in preschool children.

• Gut microbiota was characterized using both 16S rRNA and metagenomic sequencing
• MP exposure was associated with changes in gut bacterial constitution
• Total plastic concentration was significantly related to the relative abundance of microbial species
• The association with specific plastic polymers could not be attributed after adjusting for covariates

Microbial functional analysis revealed significant enrichment of 62 pathways in microplastic-exposed children.

• 62 pathways were significantly enriched in association with MP exposure
• The enriched pathways were primarily related to metabolic pathways of macronutrients, vitamins, and bioactive substances
• Functional analysis was conducted using metagenomic sequencing data

Total plastic concentration was significantly associated with the relative abundance of antibiotic resistance genes (ARGs) in preschool children's gut microbiota.

• ARG abundance was assessed via metagenomic sequencing
• Total plastic concentration showed a significant relationship with ARG relative abundance
• The association with ARGs could not be attributed to specific plastic polymers after adjusting for covariates
• The findings raise concerns about drug resistance risks particularly in younger populations

The study provides baseline data on microplastic exposure levels in preschool children, a population that has been largely unstudied regarding MP exposure.

• This is described as a multicentre cross-sectional study design
• The study identifies a gap in understanding of preschoolers' MP exposure
• The median faecal MP concentration of 212.1 μg/g dw represents baseline exposure data for this age group
• Samples were collected from three geographically distinct Chinese cities (Xiamen, Shanghai, Nanjing)