Exposure to 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine causes cecal microbiota dysbiosis in mice

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is a heterocyclic amine (HCA) that is formed during high-temperature meat cooking, especially grilling, and is classified as a carcinogenic food-borne compound that can impact multiple physiological systems. The aim of this study was to evaluate how exposure to PhIP affects the composition of the cecal microbiota in mice. A total of 32 mice were randomly divided into four groups: A negative control group, a positive control group, and two groups treated orally with either 10 or 20 mg/kg PhIP for 2 months. The V3-V4 regions of the bacterial 16S rRNA gene were sequenced to characterize the cecal microbial communities. Microbial richness and diversity decreased in the PhIP-treated mice compared to the negative control group. At the phylum level, the relative abundance of Bacillota and Actinomycetota decreased significantly after PhIP exposure, while the abundance of Campylobacterota and Bacteroidota increased. At the genus level, the abundance of Roseburia, Lactobacillus, and Bifidobacterium decreased, while the abundance of Blautia, Lachnospiraceae-NK4A136 group, Bacteroides, Alistipes, Helicobacter, and Escherichia–Shigella increased. The results highlight that bacterial community composition and its relative abundance in the cecum change with PhIP exposure and offer further evidence of microbiota dysbiosis that occurs with PhIP exposure.