Effects Of Caffeine Supplementation On Exercise Performance In Mice From Changes In Gut Microbiota

Purpose: This study looked at the effects of caffeine supplementation on exercise performance in mice based on changes in gut microbiota.Methods: Select 5-week-old male ICR mice,a total of 24.The mice were divided into three groups according to body weight: blank control group(Vehicle),1 times caffeine group(CA-1X,6mg/kg/d),5 times caffeine group(CA-5X,30mg/kg/d).After one week of pre-breeding,the mice will be supplemented with caffeine for 2 weeks,and the mice will be gavaged once a day at regular intervals.During the supplementation period,the mice will be tested for a 15-minute swimming event on the 7th day,and the mice will run on the treadmill to exhaustion on the 10 th day Test,the gas energy metabolism experiment on the 11 th day,the grip test on the forelimbs of the mice on the 12 th day,and the magnetic resonance MRI imaging of the mice on the 13 th day.The body composition of the mice was measured at the beginning of the experiment and at the end of the experiment.On day14,the mice were sacrificed and the organs were dissected and weighed.Glycogen content and blood biochemical indicators were detected,and the cecum of the mice was subjected to 16 S rRNA sequencing to analyze the gut microbiota.Mathematical statistics were used for data analysis to evaluate the changes of caffeine on the intestinal flora and energy metabolism of mice,and to comprehensively analyze the impact on exercise performance.Results:1.Effects of caffeine supplementation on blood lactic acid(LAC),creatine kinase(CK),blood ammonia(AMM)and free fatty acid(Non-estesterified fatty acid,NEFA)in mice after 15 minutes of swimming training content were significantly different(p<0.0001,p=0.0057,p<0.0001,p<0.0001).There was no significant difference for blood urea(p=0.8587).These indexes all had dose-dependent effects(p<0.0001).2.Supplementing caffeine has a significant difference in prolonging the exhaustion time of mice running(p=0.0111),CA-1X group and CA-5X group compared with Vehicle group,the exhaustion time was significantly prolonged(p=0.0018,p=0.0064),and there was a significant dose-dependent effect(p=0.0061).Caffeine had no significant effect on forelimb grip in mice(p=0.9641).3.Caffeine supplementation collected gas from mice running on a treadmill for 15 minutes,and analyzed the metabolic conditions during exercise.There were significant differences in caffeine’s carbon dioxide generation(VCO2),respiratory quotient(RQ),and energy expenditure(EE)(p=0.0021,p=0.0016,p<0.0001),during exercise,Compared with the Vehicle group,the level of VO2 in the CA-5X group was significantly increased(p=0.0196),and there was a dose-dependent effect(p=0.0200,p=0.0010,p=0.0010,p<0.0001).4.At rest,there were significant differences in average oxygen intake(Avg＿VO2),average carbon dioxide production(Avg＿VCO2),and average energy expenditure(Avg＿EE)of caffeine(p<0.0001,p=0.0003,p<0.0001),and Trend analysis showed significance(p<0.0001,p<0.0001,p<0.0001).The average respiratory quotient(Avg＿RQ)was not significantly different(p=0.939).5.Caffeine had no significant effect on liver glycogen in mice(p=0.9033).Muscle glycogen content in mice was significantly increased(p=0.0002)and increased significantly with dose levels(p<0.0259).The fat-free mass(FFM)of the mice was significantly increased(p<0.0001),and the fat content(FM)was significantly different(p=0.0386).FM was significantly lower in the CA-5X group than in the Vehicle group(p=0.0386).Meanwhile,there was a dose-dependent effect(p<0.0001,p<0.0001).Caffeine had significant effects on the levels of LDH,TG,TC and LDL in mice(p<0.0001,p<0.0001,p=0.0005,p=0.0002),Trend analysis showed significance(p<0.0001,p <0.0001,p<0.0001,p<0.0001).6.Caffeine modulated the β-diversity of the gut microbiota,with a clear sepa ration trend in the PCOA and PCA plots.Venn diagram showed that caffeine alte red the species composition of the gut microbiota.At the level of species compos ition analysis,caffeine significantly increased the relative abundance of Desferriger ia(p<0.05).Using linear discriminant analysis,it was shown that CA was able to produce species differences in gut flora,Deferribacteres,Deferribacteres,Deferrib acterales,Deferribacteraceae,Myxobacteriaceae Relative abundance of Mucispirillu m.Conclusion: Two weeks of caffeine supplementation modulated the composition of the gut microbiota,increasing the relative abundance of species involved in regulating energy metabolism,thereby affecting energy metabolism.With increased oxygen intake during exercise,the respiratory quotient decreases and energy expenditure decreases.In the resting state,the oxygen uptake is also increased,and the energy consumption is increased,and the regulation of resting metabolism provides energy utilization.And produce anti-fatigue effect by reducing fatigue-related serum markers LAC,CK,and AMM.Increases muscle glycogen stores and prolongs running to failure.In terms of body composition,fat-free content is increased,fat content is reduced,LDH,TG,and TC are reduced,NEFA is increased,and lipid metabolism is improved.Overall,caffeine altered the gut microbiota and energy metabolism network in mice,reducing fatigue and improving exercise performance.