Associations between per- and polyfluoroalkyl substances (PFAS) exposure via infant feeding and the gut microbiota of preterm infants: A study of mother-preterm infant dyads

Infants are exposed to per- and polyfluoroalkyl substances (PFAS) via feeding, yet the influence of PFAS on their gut microbiota remains poorly understood. In this study, 73 mother-preterm infant dyads were recruited in Shenzhen. We measured concentrations of 13 PFAS (PFBA, PFPeA, PFHxA, PFHpA, PFOA, PFNA, PFBS, PFHxS, PFOS, HFPO-DA, ADONA, 6:2 Cl-PFESA, and 8:2 Cl-PFESA) in the feeding substances (breast milk or formula) at the fourth week postpartum. Concurrently, fecal samples from preterm infants were collected for analysis of gut microbiota and metabolites. The highest mean concentrations were observed for two short-chain PFAS: PFBA and PFPeA. Eleven out of the 13 PFAS had detection rates exceeding 50 % and were included in subsequent analyses. Linear regression analysis indicated that daily intakes of PFBA, PFPeA, PFHxA, PFHpA, PFOA, PFNA, PFBS, and PFHxS were negatively associated with the ln-transformed PD_whole_tree index. Daily intakes of PFBA, PFBS, PFOA, and PFHxS were significantly linked with β diversity. The genus Veillonella was more abundant in the upper tertile groups of PFBA and PFBS. Moreover, daily intakes of PFHpA and PFOA were linked to predicted microbiome functions. Pathway analysis further revealed that PFAS daily intake was associated with synthesis or metabolism of multiple nutrients (including vitamins and amino acids). Notably, linear regression demonstrated that PFAS daily intake was negatively associated with levels of docosapentaenoic acid and docosahexaenoic acid. Our findings suggest that PFAS exposure through feeding may adversely affect the gut microbiota and normal development of preterm infants, potentially posing health risks.