ABSTRACT: Background: Exposure to persistent organic pollutants (POPs) and disruptions in the gastrointestinal microbiota have been positively correlated with a predisposition to factors such as obesity, metabolic syndrome, and type 2 diabetes; however, it is unclear how the microbiome contributes to this relationship.
Objective: This study aimed to explore the association between early-life exposure to a potent aryl hydrocarbon receptor (AHR) agonist and persistent disruptions in the microbiota, leading to impaired metabolic homeostasis later in life.
Methods: This study utilized metagenomics, NMR- and mass spectrometry-based metabolomics, and biochemical assays to analyze the gut microbiome composition and function, as well as the physiological and metabolic effects of early-life exposure to 2,3,7,8-tetrachlorodibenzofuran (TCDF) in conventional, germ-free (GF), and Ahr-null mice. The impact of TCDF on Akkermansia muciniphila (A. muciniphila) in vitro was assessed using optical density (OD 600), flow cytometry, transcriptomics, and mass spectrometry-based metabolomics.
Results: TCDF-exposed mice exhibited disruption in the gut microbiome community structure and function, characterized by lower abundances of A. muciniphila, lower levels of cecal short chain fatty acids (SCFAs) and indole-3-lactic acid (ILA), and a reduction in gut hormones GLP-1 and PYY. Importantly, microbial and metabolic phenotypes associated with early-life POP exposure were transferable to GF recipients in the absence of POP carry-over. In addition, AHR-independent interactions between POPs and the microbiota were observed, significantly affected the growth, physiology, gene expression, and metabolic activity of A. muciniphila, resulting in suppressed activity along the ILA pathway.
Conclusions: These data point to the complex effects of POPs on the host and microbiota, providing strong evidence that early-life, short-term, and self-limiting POP exposure can adversely impact the microbiome, persisting into later life with associated health implications.
Andrew D. Patterson 
