Plain language summary
Endothelial dysfunction is an early warning sign for plaque formation in atherosclerosis. This study explores the Biﬁdobacterium animalis subsp. Lactis (Bifal) and arginine (Arg) on endothelial function in forty-four healthy subjects. The subjects were randomised to receive 100g daily of natural yoghurt containing Bifal and Arg, or a placebo, for a total of twelve weeks. In a precursor to this study, the authors found that Bifal and Arg increased the production of certain polyamines in the gut, essential to cell proliferation and inhibition of inflammation. They concluded that exogenous polyamines from foods may be of benefit to cardiovascular health. In this follow-up study they measured fecal, blood and urine samples to analyse polyamine concentration, bacterial DNA, serum polyamine, inflammatory cytokines, triglycerides and other biochemical parameters. The reactive hyperemia index (RHI), the primary outcome, was measured using endo-peripheral arterial tone (EndoPAT). The results showed that the participants who received the Bifal and Arg yoghurt saw their RHI increase from 1.50 to 1.81, suggesting that Bifal + Arg YG intake restored endothelial function to normal levels. The other biomarkers measured also suggested an improvement of vascular endothelial function with a reduction in serum platelet and triglyceride levels, two risk factors for atherosclerosis.