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

Purpose Intestinal 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). Methods In 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. Results Two-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. Conclusion These findings suggest that exercise-induced intestinal cellular damage/injury is partly implicated in changes in permeability but other factors must also contribute

The effect of bovine colostrum supplementation on intestinal injury and circulating intestinal bacterial DNA following exercise in the heat

Purpose Exercise-induced changes in intestinal permeability are exacerbated in the heat. The aim of this study was to determine the effect of 14 days of bovine colostrum (Col) supplementation on intestinal cell damage (plasma intestinal fatty acid-binding protein, I-FABP) and bacterial translocation (plasma bacterial DNA) following exercise in the heat. Methods In a double-blind, placebo-controlled, crossover design, 12 males completed two experimental arms (14 days of 20 g/day supplementation with Col or placebo, Plac) consisting of 60 min treadmill running at 70% maximal aerobic capacity (30 ??C, 60% relative humidity). Blood samples were collected pre-exercise (Pre-Ex), post-exercise (Post-Ex) and 1 h post-exercise (1 h Post-Ex) to determine plasma I-FABP concentration, and bacterial DNA (for an abundant gut species, Bacteroides). Results Two-way repeated measures ANOVA revealed an arm ?~ time interaction for I-FABP (P = 0.005, with greater Post- Ex increase in Plac than Col, P = 0.01: Plac 407 ?} 194% of Pre-Ex vs Col, 311 ?} 134%) and 1 h Post-Ex (P = 0.036: Plac 265 ?} 80% of Pre-Ex vs Col, 229 ?} 56%). There was no interaction (P = 0.904) but there was a main effect of arm (P = 0.046) for plasma Bacteroides/total bacterial DNA, with lower overall levels evident in Col. Conclusion This is the first investigation to demonstrate that Col can be effective at reducing intestinal injury following exercise in the heat, but exercise responses (temporal pattern) of bacterial DNA were not influenced by Col (although overall levels may be lower).publishersversionPeer reviewe

Oral Serum-Derived Bovine Immunoglobulin/Protein Isolate Has Immunomodulatory Effects on the Colon of Mice that Spontaneously Develop Colitis

Dietary immunoglobulin concentrates prepared from animal plasma can modulate the immune response of gut-associated lymphoid tissue (GALT). Previous studies have revealed that supplementation with serum-derived bovine immunoglobulin/protein isolate (SBI) ameliorates colonic barrier alterations in the mdr1a-/- genetic mouse model of IBD. Here, we examine the effects of SBI on mucosal inflammation in mdr1a-/- mice that spontaneously develop colitis. Wild type (WT) mice and mice lacking the mdr1a gene (KO) were fed diets supplemented with either SBI (2% w/w) or milk proteins (Control diet), from day 21 (weaning) until day 56. Leucocytes in mesenteric lymph nodes (MLN) and in lamina propria were determined, as was mucosal cytokine production. Neutrophil recruitment and activation in MLN and lamina propria of KO mice were increased, but were significantly reduced in both by SBI supplementation (p < 0.05). The increased neutrophil recruitment and activation observed in KO mice correlated with increased colon oxidative stress (p < 0.05) and SBI supplementation reduced this variable (p < 0.05). The Tact/Treg lymphocyte ratios in MLN and lamina propria were also increased in KO animals, but SBI prevented these changes (both p < 0.05). In the colon of KO mice, there was an increased production of mucosal proinflammatory cytokines such as IL-2 (2-fold), IL-6 (26-fold) and IL-17 (19-fold), and of chemokines MIP-1β (4.5-fold) and MCP-1 (7.2-fold). These effects were significantly prevented by SBI (p < 0.05). SBI also significantly increased TGF-β secretion in the colon mucosa, suggesting a role of this anti-inflammatory cytokine in the modulation of GALT and the reduction of the severity of the inflammatory response during the onset of colitis

Saccade-related BOLD activity.

<p>(<b>A</b>) Saccade execution was associated with robust activity in bilateral medial occipital cortex, putamen, pulvinar, and LGN as compared to cued fixation trials based on the standard HRF model (<i>6sec-model</i>). (<b>B</b>) The same contrast derived from the alternative <i>4.5sec-model</i> (i.e., optimized for the SC) revealed robust saccade-related activity within both the left and right SC. (<b>C</b>) The direct comparison between centrifugal and centripetal saccades revealed higher activity within the SC (<i>4.5sec-model</i>) as well as a stronger prefrontal deactivation for the former (<i>6sec-model</i>). Activations are displayed on the averaged T1-weighted image. Display cut off: T>2.5, extent threshold k>15.</p

ROI-based parameter estimates and FIR time courses.

<p>(<b>A</b>) The analysis of parameter estimates (beta values) revealed enhanced activity in the left SC during saccades into the right visual field and vice versa, as well as enhanced SC activity for centrifugal as compared to centripetal saccades. Data are collapsed across hemispheres displaying collicular activity contralateral (contra) and ipsilateral (ipsi) to the saccade direction. Leftward saccades are considered to be contralateral with respect to the right SC, and ipsilateral with respect to the left SC. Similarly, rightward saccades are considered contralateral and ipsilateral with respect to the left and right SC, respectively. (<b>B</b>) At the same time, centrifugal saccades were associated with a robust prefrontal deactivation that was significantly smaller during centripetal saccades. Data are collapsed across hemispheres and saccade direction. The corresponding ROI-based time courses closely match the differences in parameter estimates within SC (<b>C</b>) and mPFC (<b>D</b>). ROIs were defined orthogonally to condition-specific patterns, i.e. anatomically regarding the SC and on the basis of the contrast <i>‘all saccades versus fixation’</i> within mPFC. Representative ROI locations are displayed on a single-subject's T1-weighted image in the center. Error bars in panels A and B depict the standard error (SE) in each condition across subjects.</p