Background:Thephysiologicalandbiochemicaldemandsofintenseexerciseelicitbothmuscle-basedandsystemicresponses.Themainadaptationstoenduranceexerciseincludethecorrectionofelectrolyteimbalance,adecreaseinglycogenstorageandtheincreaseofoxidativestress,intestinalpermeability,muscledamage,andsystemicinflammatoryresponse.Adaptationstoexercisemightbeinfluencedbythegutmicrobiota,whichplaysanimportantroleintheproduction,storage,andexpenditureofenergyobtainedfromthedietaswellasininflammation,redoxreactions,andhydrationstatus.Methods:Asystematicandcomprehensivesearchofelectronicdatabases,includingMEDLINE,Scopus,ClinicalTrials.gov,ScienceDirect,SpringerLink,andEMBASEwasdone.Thesearchprocesswascompletedusingthekeywords:'endurance','exercise','immuneresponse','microbiota','nutrition',and'probiotics'.Results:Reviewedliteraturesupportsthehypothesisthatintestinalmicrobiotamightbeabletoprovideameasureable,effectivemarkerofanathlete'simmunefunctionandthatmicrobialcompositionanalysismightalsobesensitiveenoughtodetectexercise-inducedstressandmetabolicdisorders.Thereviewalsosupportsthehypothesisthatmodifyingthemicrobiotathroughtheuseofprobioticscouldbeanimportanttherapeutictooltoimproveathletes'overallgeneralhealth,performance,andenergyavailabilitywhilecontrollinginflammationandredoxlevels.Conclusion:Thepresentreviewprovidesacomprehensiveoverviewofhowgutmicrobiotamayhaveakeyroleincontrollingtheoxidativestressandinflammatoryresponsesaswellasimprovingmetabolismandenergyexpenditureduringintenseexercise.
