Anthocyanin-Rich Blackcurrant Extract Preserves Gastrointestinal Barrier Permeability and Reduces Enterocyte Damage but Has No Effect on Microbial Translocation and Inflammation After Exertional Heat Stress

Abstract

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 min in an environmental chamber (34 °C, 40% relative humidity) on two occasions (placebo/blackcurrant, randomized double-blind crossover). Permeability was assessed from a 4-hr urinary excretion of lactulose and rhamnose and expressed as a ratio of lactulose/rhamnose. Venous blood samples were taken at rest and 20, 60, and 240 min after exercise to measure enterocyte damage (intestinal fatty acid-binding protein); microbial translocation (soluble CD14, lipopolysaccharide-binding protein); and interleukins 6, interleukins 10, and interleukins 1 receptor antagonist. Exercise increased rectal temperature (by ∼2.8 °C) and heart rate (by ∼123 beats/min) in each condition. Blackcurrant supplementation led to a ∼12% reduction in lactulose/rhamnose ratio (p < .0034) and enterocyte damage (∼40% reduction in intestinal fatty acid-binding protein area under the curve; p < .0001) relative to placebo. No between-condition differences were observed immediately after exercise for lipopolysaccharide-binding protein (mean, 95% confidence interval [CI]; +80%, 95% CI [+61%, +99%]); soluble CD14 (+37%, 95% CI [+22%, +51%]); interleukins 6 (+494%, 95% CI [+394%, +690%]); interleukins 10 (+288%, 95% CI [+105%, +470%]); or interleukins 1 receptor antagonist (+47%, 95% CI [+13%, +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 subclinical levels, this had no effect on microbial translocation and downstream inflammatory processes.

Dysbiosis in gastrointestinal pathophysiology: Role of the gut microbiome in Gulf War Illness

“…In clinical situation, changes in the types of diet can be easy for some people patients but hard for others. The development of supplements that contain various phytochemicals with anti-inflammatory effects 77,80,85 or milk glycan that improves gut microbiota profile 74 may help reducing the symptoms and/or can ameliorate the impacts of high-fat diet. Many studies have been done on the potential pharmaceutical treatments for GWI.…”

“…Studies using animal models showing the causation of the symptoms of GWI are also accumulating (Figure 2, Table 2). The new studies showing promising results to improve the GWI symptoms can be the new directions in treating GWI: the intestine EVs, 57 utilization of the phytochemicals with anti-inflammatory effects 77,80,85,91 and reducing the intake of highfat diet. 90 All of these have shown positive results in animal model studies as shown above.…”

Exertional heat stroke: nutritional considerations

“…May ↓ intestinal permeability and microbial translocation, but findings are inconsistent (Ashton et al., 2003 ; Kuennen et al., 2011 ; Lee et al., 2022 ; Szymanski et al., 2018 )…”

“…For example, 3 weeks of quercetin (1 g day −1 ) had no influence on plasma cytokine responses to 3 h of moderate‐intensity cycling, but a single 2 g dose blunted intestinal permeability, microbial translocation and plasma TNF‐α following 40 min of exertional‐heat stress (Kuennen et al., 2011 ; Nieman et al., 2007 ). One recent human study reported that 7 days’ supplementation with anthocyanin‐rich blackcurrant extract, another flavonoid antioxidant, protected intestinal permeability in response to exertional‐heat stress; however, these benefits did not extend to blunted microbial translocation or systemic inflammation (Lee et al., 2022 ).…”

“…• ↓ Intestinal permeability and epithelial injury(Davison et al, 2016;March et al, 2019) • Less effective with greater exertional-heat stress(McKenna et al, 2017;Morrison et al, 2014) • May ↓ intestinal permeability and microbial translocation, but findings are inconsistent(Ashton et al, 2003;Kuennen et al, 2011;Lee et al, 2022;Szymanski et al, 2018) • More evidence is requiredProbiotics• No beneficial effects in humans(Mooren et al, 2020;Pugh et al, 2019Pugh et al, , 2020Shing et al, 2014) • May ↑ endotoxaemia and cytokinaemia(Gill et al, 2016) • More evidence is required Arginine • No beneficial effects in humans (Buchman et al, 1999) • More evidence is required GI, gastrointestinal; HSP, heat-shock protein. [Correction made on 28 June 2022, after first online publication: Incorrect references were cited in Table 1; the correct references have been cited in this version.]…”