Elevated Hair Cortisol Is Associated With a Distinct Gut Microbiome

Objectives: The objective of this analysis was to examine the association of chronic stress, measured using an objective biomarker, hair cortisol concentration, and the gut microbiome among racially diverse middle to older age adults from Chicago, IL. Methods: Fifty-six patients that completed a colonoscopy for colorectal cancer screening at two urban academic medical institutions were recruited between 2017 and early 2020. Stool, hair, anthropometrics, and survey data including diet and lifestyle was collected. Hair cortisol concentration was measured via immunoassay and elevated hair cortisol was defined as >4.1pg/mg based on a median split. Shotgun metagenomics was performed on stool samples. Microbial features, including alpha and beta diversity, differential abundances of bacteria at the genus level and KEGG orthologs and functional enrichment analysis were analyzed using R statistical packages. Results are corrected for false discovery rate. Results: Participants were 64% female, 49% Black race, and had a mean age of 60 (± 6.1) years. Individuals with elevated hair cortisol were significantly more likely to self-identify as Black race, have a body mass index ≥ 30 kg/m2, and reside in a community area of Chicago with high poverty and homicide rates. Diet quality (HEI-2015) was similar between groups. Community alpha and beta-diversity was similar between the low and high hair cortisol groups. The relative abundance of 70 microbial taxa including Fusobacterium, Parabacteroides and Sutterela was higher (p < 0.05) in those with hair cortisol >4.1pg/mg. 155 microbial gene features were differently abundant (p < 0.05) between the hair cortisol groups with 92 more abundant in those with hair cortisol >4.1pg/mg with several genes related to metal transport (e.g., Fe, Cu). Conclusions: Increased hair cortisol concentration is associated with an altered gut microbiome. Our data suggest that the impact of stress in the development of chronic conditions and health disparities may be partially mediated through the gut microbiome. Funding Sources: LTH, PG, EM, JR, HRH: R01CA204808, U54MD012523; MLO: T32CA057699.