Effect Of Acute Exercise On Intestinal Mucosal Barrier Function And Immune Response In Athletes

BackgroundThe intestinal mucosal barrier is an important line of defense for the body against invasion by external pathogenic microorganisms.The homeostatic maintenance of the intestinal mucosal barrier is an important factor for athletes to maintain optimum athletic performance.This study explored the effects of acute exercise at different intensities on the intestinal mucosal barrier function of athletes using risk assessment of functional gastrointestinal illnesses and intestinal permeability tests.It also provided fresh methods for keeping track of how the digestive system’s physiological functions changed during exercise training.MethodsIn the first part of the study,97 non-athletes,112 endurance athletes,and 95non-endurance athletes were recruited using a questionnaire to assess the risk of functional gastrointestinal disease in the subjects using the Rome IV Diagnostic Questionnaire for Functional Gastrointestinal Disease in Adults.The second part of the study was a human trial in which six athletes were recruited in a randomized crossover own pre/post control design to explore the application of a non-invasive intestinal permeability assay in athletes and to observe the effect of acute moderate-intensity exercise on intestinal permeability.The acute moderate-intensity exercise protocol was an hour of cycling exercise at 60% maximal oxygen uptake.The intestinal permeability assay was performed by orally administering lactulose and mannitol,which were not absorbed by the body under normal physiological conditions,and measuring the concentration of these substances in urine after 4 hours and calculating the ratio.The third part of the study was a human trial in which 12 athletes in endurance events were recruited to explore the effects of acute high-intensity exercise on intestinal mucosal barrier function using a before-and-after control design of their own.The exercise protocol was an hour-long run at 80% maximal oxygen uptake.Lactulose and mannitol solution before exercise and urine collection 2 hours after exercise.Blood was collected before exercise,immediately after exercise,1 hour after exercise,2 hours after exercise and 24 hours after exercise to measure peripheral blood intestinal fatty acid binding protein(I-FABP),and zonulin.Immune function indicators included peripheral blood interleukin(IL-6),IL-10,immunoglobulin A(Ig A),C-reactive protein(CRP),and lymphocyte typing.ResultsThe first part of the study found that lower gastrointestinal symptoms were more prevalent in endurance event athletes.The frequency of recent abdominal flatulence,abdominal pain,pasty or watery stools,and urge to defecate was significantly higher in endurance event athletes than in both non-athletes and non-endurance event athletes(P<0.01).The second part of the study found no statistically significant differences in lactose/mannitol in the urine of athletes in the quiet state and after acute moderate to moderate intensity exercise.The third part of the study found a significant increase in lactulose/mannitol in the urine of athletes after acute high-intensity exercise compared to pre-exercise(P<0.05);a significant increase in peripheral blood I-FABP and zonulin immediately after exercise(P<0.01);a significant increase in peripheral blood IL-6 and IL-10 concentrations immediately,1 hour and 2 hours after exercise(P<0.01);and a significant increase in CRP concentrations increased significantly 24 hours after exercise(P<0.05).Ig A was significantly lower at all time points after acute high-intensity exercise than before exercise(P<0.05).Peripheral blood neutrophils were significantly increased(P<0.01)and total T lymphocytes,total B lymphocytes,helper T cells,cytotoxic T cells,and natural killer cell(NK)counts were significantly decreased(P<0.05)immediately after acute heavy exercise,and zonulin were significantly associated with IL-10(P=0.01,r=0.69)and IL-6(P= 0.01,r=0.83)positively,and I-FABP positively correlated with IL-10(P=0.04,r=0.58)and negatively with Ig A(P=0.02,r=-0.66).ConclusionThis study found that endurance athletes were at higher risk for functional gastrointestinal disease.Acute high-intensity exercise increased intestinal permeability in athletes,and acute moderate-intensity exercise had no significant effect on intestinal permeability.There was a correlation between changes in intestinal mucosal barrier function indicators and immune function indicators after acute high-intensity exercise.Therefore,functional gastrointestinal disease risk factor screening,intestinal mucosal barrier function testing and immune function assessment should be integrated in training monitoring to promote the occupational health of athletes in endurance events.