Global, distinctive, and personal changes in molecular and microbial profiles by specific fibers in humans

Dietary fibers act through the microbiome to improve cardiovascular health and prevent metabolic disorders and cancer. To understand the health benefits of dietary fiber supplementation, we investigated two popular purified fibers, arabinoxylan (AX) and long-chain inulin (LCI), and a mixture of five fibers. We present multiomic signatures of metabolomics, lipidomics, proteomics, metagenomics, a cytokine panel, and clinical measurements on healthy and insulin-resistant participants. Each fiber is associated with fiber-dependent biochemical and microbial responses. AX consumption associates with a significant reduction in LDL and an increase in bile acids, contributing to its observed cholesterol reduction. LCI is associated with an increase in Bifidobacterium. However, at the highest LCI dose, there is increased inflammation and elevation in the liver enzyme alanine aminotransferase. This study yields insights into the effects of fiber supplementation and the mechanisms behind fiber-induced cholesterol reduction, and it shows effects of individual, purified fibers on the microbiome.

Automated summary

Dietary fibers play a role in improving cardiovascular health, preventing metabolic disorders and cancer through their impact on the microbiome. This study examined the effects of different types of fibers on various markers, including metabolomics, lipidomics, proteomics, metagenomics, cytokine panel, and clinical measurements. Each fiber showed fiber-dependent biochemical and microbial responses. Arabinoxylan (AX) intake was associated with reduced LDL and increased bile acids, contributing to cholesterol reduction. Long-chain inulin (LCI) intake led to an increase in Bifidobacterium, but at high doses, it also caused inflammation and elevated liver enzyme levels. This study provides insights into the mechanisms of fiber-induced cholesterol reduction and the effects of individual fibers on the microbiome.