The Gut-Liver Axis: Phytochemicals as Modulators of Cardiovascular Health

A recent synthesis shows dietary phytochemicals modulate the gut–liver axis in ways directly relevant to cardiovascular risk, targeting microbiota composition, intestinal barrier integrity, and bile acid regulation—mechanisms that may affect atherosclerosis development.

Gut microbes metabolize these compounds into transformed products that shift microbial composition and function. Microbial metabolites, including short-chain fatty acids and other bioactive molecules, change hepatic lipid handling and inflammatory signaling, creating a plausible diet-to-cardiovascular pathway.

Polyphenols, carotenoids, and saponins exert class-specific effects on the intestinal barrier and liver. Polyphenols are associated with increased tight-junction expression via antioxidant pathways; carotenoids correlate with reduced endotoxin translocation; saponins have been linked to modulation of hepatic steatosis in human and preclinical studies. Collectively, barrier protection lowers hepatic inflammatory load.

Phytochemicals also reduce systemic inflammation through antioxidant and anti-inflammatory mechanisms along the gut–liver axis. Microbiome-driven shifts alter bile-acid pools and downstream signaling through FXR and TGR5, with consequent effects on lipid metabolism and vascular inflammation—pathways integral to atherosclerosis.