Intestinal fatty acid-binding protein and gut permeability responses to exercise

Abstract

PurposeIntestinal cell damage due to physiological stressors (e.g. heat, oxidative, hypoperfusion/ischaemic) may contribute to increased intestinal permeability. The aim of this study was to assess changes in plasma intestinal fatty acid-binding protein (I-FABP) in response to exercise (with bovine colostrum supplementation, Col, positive control) and compare this to intestinal barrier integrity/permeability (5 h urinary lactulose/rhamnose ratio, L/R).MethodsIn a double-blind, placebo-controlled, crossover design, 18 males completed two experimental arms (14 days of 20 g/day supplementation with Col or placebo, Plac). For each arm participants performed two baseline (resting) intestinal permeability assessments (L/R) pre-supplementation and one post-exercise following supplementation. Blood samples were collected pre- and post-exercise to determine I-FABP concentration.ResultsTwo-way repeated measures ANOVA revealed an arm × time interaction for L/R and I-FABP (P < 0.001). Post hoc analyses showed urinary L/R increased post-exercise in Plac (273% of pre, P < 0.001) and Col (148% of pre, P < 0.001) with post-exercise values significantly lower with Col (P < 0.001). Plasma I-FABP increased post-exercise in Plac (191% of pre-exercise, P = 0.002) but not in the Col arm (107%, P = 0.862) with post-exercise values significantly lower with Col (P = 0.013). Correlations between the increase in I-FABP and L/R were evident for visit one (P = 0.044) but not visit two (P = 0.200) although overall plots/patterns do appear similar for each.ConclusionThese findings suggest that exercise-induced intestinal cellular damage/injury is partly implicated in changes in permeability but other factors must also contribute.

Reliability of gastrointestinal barrier integrity and microbial translocation biomarkers at rest and following exertional heat stress

“…Following both EHSTs, I‐FABP increased by approximately 50% or 0.800 ng ml −1 . This response is comparable to numerous similar duration/intensity exercise protocols, such as: 45‐to‐60 min of ~70% watt max normothermic cycling (van Wijck et al, , [61%, Δ 0.306 ng ml −1 ] 2012, [61%; Δ 0.179 ng ml −1 ] and 20–30 min of ~80% VO 2max running (Barberio et al, [46%, Δ 0.297 ng ml −1 ]; March et al, [72%; Δ 0.350 ng ml −1 ]). In comparison, far greater elevations in I‐FABP have been shown following 90–120 min of moderate‐intensity running performed in the heat (30°C; Morrison, Cheung, & Cotter, [663%; Δ 0.203–0.806 ng ml −1 ]; Snipe et al, [288%, Δ 0.897 ng ml −1 ]; 2018 [432%, Δ 1.230 ng ml −1 ].…”

“…Given general logistical constraints of the urine/serum DSAT, the majority of relevant evidence has attempted to validate (correlate) this method against more practical GI barrier integrity biomarkers. These studies generally report significant, though weak correlations ( r = 0.4–0.6) between basal corrected (Δ) DSAT (urine 5 hr) and I‐FABP responses directly following moderate GI barrier integrity loss (March et al, ; van Wijck et al, , ). In this study, the DSAT did not correlate with any other GI integrity biomarker.…”

Intestinal damage following short-duration exercise at the same relative intensity is similar in temperate and hot environments

“…Indeed Morrison et al (2014) have reported an increase in I-FABP of 563% following 90 min of cycling and running in 30°C with an end core temperature of 38.75°C, while Barberio et al (2015) reported an increase of only 46% following 26 min of running in 40 degrees with an end core temperature of 39.0°C at a similar intensity. In support of the hypothesis that the magnitude of exercise induced intestinal damage is not related to environmental temperature we have combined the present group mean data with data from other studies that simultaneously report the post-exercise change in I-FABP in combination with end exercise core temperature, participants V O 2max (indicative of training status), and exercise duration and intensity (Morrison et al 2014;Barberio et al 2015;March et al 2017;McKenna et al 2017;Snipe et al 2018a). There was a significant correlation between environmental temperature (range 22°C to 40°C) and end exercise core temperature (range 38.2°C to 39.6°C) (r=0.79, p=0.011), however; there was no significant correlation between the magnitude of intestinal damage and core temperature (r=0.3, p=0.43), suggesting that other factors contribute to the extent of damage.…”

Irisin reverses intestinal epithelial barrier dysfunction during intestinal injury via binding to the integrin αVβ5 receptor

“…19 Previous studies have demonstrated that gut barrier dysfunction after gut IR is mainly caused by metabolic disorders and destruction of enterocytes, which can benefit from exercise. 30,31 However, the effects of irisin on the intestinal barrier have not been elucidated to date. In this study, F I G U R E 7 Genipin abolished the protective role of irisin in gut IR.…”