Intake of Fiber From Different Food Sources and Type 2 Diabetes Risk: An Integrated Analysis of Epidemiological and Multiomic Data

OBJECTIVE: To examine the association between fiber from various food sources and type 2 diabetes (T2D) risk, as well as the molecular profiles involved. RESEARCH DESIGN AND METHODS: Using data from three large prospective U.S. cohorts comprising 195,222 participants observed for up to 34 years, we evaluated the association between fiber from various food sources and T2D risk. We also assessed the association between fiber intake, plasma metabolic biomarkers, and a metabolomic profile indicative of T2D risk. Additionally, we examined gut microbial features related to fiber intake and the T2D metabolomic profile. RESULTS: During follow-up, we documented 18,369 incident T2D cases. Higher intakes of total fiber (hazard ratio [HR] comparing extreme quintiles 0.88; 95% CI 0.82, 0.94), cereal fiber (HR 0.77; 95% CI 0.73, 0.82), and fruit fiber (HR 0.82; 95% CI 0.78, 0.87) were each associated with a lower T2D risk. Greater intakes of total fiber, cereal fiber, and fruit fiber, but not vegetable fiber, were linked to more favorable plasma profiles of insulinemic, lipid, and inflammatory biomarkers and a metabolomic profile indicative of a lower T2D risk. We also identified multiple gut microbial species, such as Faecalibacterium prausnitzii, Ruminococcus lactaris, and Gemmiger formicilis, along with relevant butyric acid-producing enzymes, all of which were associated with higher fruit fiber intake and a metabolomic profile indicating a lower likelihood of T2D development. CONCLUSIONS: Higher intakes of total, cereal, and fruit fiber are associated with a lower risk of T2D and a more favorable metabolic profile, with the gut microbiome potentially contributing to the beneficial association of fruit fiber.