This study investigated the effects of 7 days of 600 mg/day anthocyanin-rich blackcurrant extract intake on small intestinal permeability, enterocyte damage, microbial translocation and inflammation following exertional heat stress. Twelve recreationally active men (maximal aerobic capacity = 55.6 ± 6.0 mL.kg-1.min-1) ran (70% VO2max) for 60 minutes in an environmental chamber (34°C, 40% relative humidity) on two occasions (Placebo/Blackcurrant, randomized double-blind cross over). Permeability was assessed from a 4-hour urinary excretion of lactulose (L) and rhamnose (R) and expressed as a ratio of L/R. Venous blood samples were taken at rest and 20, 60 and 240 min after exercise to measure enterocyte damage (intestinal fatty acid binding protein, I-FABP), microbial translocation (sCD14; lipopolysaccharide binding protein, LBP), and interleukins 6 (IL-6), 10 (IL-10) and 1 receptor antagonist (IL-1RA). Exercise increased rectal temperature (by ~2.8 °C) and heart rate (by ~123 beats.min-1) in each condition. Blackcurrant supplementation led to a) ~12% reduction in L/R ratio (p<0.0034) and enterocyte damage (~40% reduction in I-FABP area under the curve, AUC; p<0.0001) relative to placebo. No between condition differences were observed immediately after exercise for LBP (+80%, +61 to +99%; mean, 95% confidence interval), sCD14 (+37%, +22 to +51%), IL-6 (+494%, +394 to +690%), IL-10 (+288%, +105 to +470%) or IL-1RA (+47%, +13 to +80; all time main effects). No between-condition differences for these markers were observed after 60 or 240 min of recovery. Blackcurrant extract preserves the GI barrier, however at sub-clinical levels this had no effect on microbial translocation and downstream inflammatory processes.