A single-center, double-blind, placebo-controlled randomized trial to test the effects of 14 days of beetroot juice supplementation on functional and biological outcomes in adults with long-COVID.
Participants were randomized 1:1 to receive either daily oral supplementation with 200 mL beetroot juice or placebo for 14 days. The primary endpoint was the change from baseline to day 14 in the fatigue resistance test. Secondary outcomes included the distance walked on the 6-min walk test, handgrip strength, and flow-mediated dilation. Secondary endpoints also included changes from baseline in circulating inflammatory mediators, metagenomic and fecal water metabolomic profiles. Partial least squares discriminant analysis (PLS-DA) models were built to evaluate the differences in biological variables associated with the interventions.
