Childhood Adiposity and Bisphenol Exposure Are Linked to Gut Dysbiosis, Altered Short-Chain Fatty Acid and Complex Carbohydrate-Degrading Profiles

Background: Dietary exposure to endocrine-disrupting chemicals is increasingly associated with pediatric adiposity and gut dysbiosis. Although short-chain fatty acids (SCFAs) are traditionally known for being involved in metabolic homeostasis, their contribution to energy harvesting remains controversial and under continuous debate. Methods: We conducted an integrative study of 100 children (aged 3–12 years) stratified by BMI and total body fat percentage, with bisphenol exposure assessed via nail matrix biomonitoring. Gut microbiota was profiled via amplicon gene sequencing, fecal SCFAs were quantified by GC-MS, and the genomic capacity for complex carbohydrate degradation was predicted using functional profiling tools. Results: Children with high body fat percentage exhibited higher fecal concentrations of acetate, butyrate, and propionate. High bisphenol levels were also positively associated with both increased adiposity and elevated fecal SCFA profiles. Integrative analyses identified a distinct microbiota-metabolic signature: obesity and high bisphenol exposure were linked to an expansion of specific taxa such as Blautia, Collinsella, and Catenibacterium, contrasting with a reduction in potential protective markers including Oscillospiraceae, Bacteroides plebeius, and Christensenellaceae R-7. Notably, key functional and gene-enzymatic profiling revealed an enriched carbohydrate-degrading potential within the adiposity and BPA-associated microbiota, consistent with enhanced fiber degradation, increased SCFA production, and greater predicted energy-extracting potential. Conclusions: The co-occurrence of host metabolic and environmental factors together with the altered microbiome features, points towards a shift in microbial energy harvesting. The findings outline a correlative ‘chemical obesogen–microbiome–adiposity’ interplay, linking environmental xenobiotic exposure to specific microbial alterations and metabolic changes associated with pediatric fat accumulation.