An Empirical Dietary Pattern Associated With the Gut Microbial Features in Relation to Colorectal Cancer Risk.

Background & Aims: Epidemiologic evidence for dietary influence on colorectal cancer (CRC) risk through the gut microbiome remains limited.
Methods: Leveraging 307 men and 212 women with stool metagenomes and dietary data, we characterized and validated a sex-specific dietary pattern associated with the CRC-related gut microbial signature (CRC Microbial Dietary Score [CMDS]). We evaluated the associations of CMDS with CRC risk according to Fusobacterium nucleatum, pks ⁺ Escherichia coli, and enterotoxigenic Bacteroides fragilis status in tumor tissue using Cox proportional hazards regression in the Health Professionals Follow-Up Study (1986-2018), Nurses' Health Study (1984-2020), and Nurses' Health Study II (1991-2019).
Results: The CMDS was characterized by high industrially processed food and low unprocessed fiber-rich food intakes. In 259,200 participants, we documented 3854 incident CRC cases over 6,467,378 person-years of follow-up. CMDS was associated with a higher risk of CRC (P _trend < .001), with a multivariable hazard ratio (HR _{Q5 vs Q1} ) of 1.25 (95% CI, 1.13-1.39). The association remained after adjusting for previously established dietary patterns, for example, the Western and prudent diets. Notably, the association was stronger for tumoral F nucleatum-positive (HR _{Q5 vs Q1} , 2.51; 95% CI, 1.68-3.75; P _trend < .001; P _{heterogeneity}  = .03, positivity vs negativity), pks ⁺ E coli-positive (HR _{Q5 vs Q1} , 1.68; 95% CI, 0.84-3.38; P _trend  = .005; P _{heterogeneity}  = .01, positivity vs negativity), and enterotoxigenic Bacteroides fragilis-positive CRC (HR _{Q5 vs Q1} , 2.06; 95% CI, 1.10-3.88; P _trend  = .016; P _{heterogeneity}  = .06, positivity vs negativity), compared with their negative counterparts.
Conclusions: CMDS was associated with increased CRC risk, especially for tumors with detectable F nucleatum, pks ⁺ E coli, and enterotoxigenic Bacteroides fragilis in tissue. Our findings support a potential role of the gut microbiome underlying the dietary effects on CRC.
(Copyright © 2024 AGA Institute. Published by Elsevier Inc. All rights reserved.)