Fasting alters the gut microbiome reducing blood pressure and body weight in metabolic syndrome patients

Summary

This randomized controlled trial enrolled 71 adults with metabolic syndrome and randomized them to a five-day modified Buchinger-style fast followed by a modified DASH diet versus DASH diet alone. Investigators measured 16S rRNA gut microbiome composition, ambulatory blood pressure, antihypertensive medication requirements, and standard cardiometabolic biomarkers at baseline, immediately post-fast, and at three months follow-up. The fasting plus DASH arm showed greater reductions in systolic blood pressure, in the requirement for antihypertensive medications, and in body-mass index at three months than the DASH-only arm. Gut microbiome analysis identified specific bacterial taxa — including changes in genera linked to short-chain fatty acid production and to microbial pathways relevant to host metabolic regulation — that responded to the fast, with changes that partly persisted into the post-fast period. The paper is one of the few human RCTs to combine a multi-day fasting intervention with comprehensive microbiome characterization and clinically meaningful blood pressure endpoints.