Gastrointestinal TractDigestive SystemDigestive System Physiological PhenomenaAdministration, OralUpper Gastrointestinal TractGastrointestinal NeoplasmsGastrointestinal DiseasesLower Gastrointestinal TractStomachIntestinal MucosaIntestinesUrinary Tract InfectionsIntestine, SmallColonCecumFecesUrinary TractIntestine, LargeTime FactorsInjections, IntravenousDuodenumIntestinal AbsorptionDrug Administration ScheduleDose-Response Relationship, DrugRats, Sprague-DawleyGastrointestinal MotilityGastric MucosaEnteric Nervous SystemGerm-Free LifeIleumRats, WistarGastrointestinal ContentsJejunumUnited States Food and Drug AdministrationLactobacillusDisease Models, AnimalRespiratory Tract InfectionsProbioticsBiological AvailabilityTissue DistributionLiverPyramidal TractsMice, Inbred C57BLGastrointestinal HemorrhageDrug Administration RoutesGastrointestinal TransitEndoscopy, GastrointestinalEsophagusImmunohistochemistryAdministration, IntranasalSwineMice, Inbred BALB CInjections, IntraperitonealDogsGastrointestinal Stromal TumorsDigestionRNA, MessengerIntubation, GastrointestinalAdministration, RectalInjections, SubcutaneousBifidobacteriumRats, Inbred StrainsTreatment OutcomeStomach DiseasesInflammatory Bowel DiseasesLactobacillus reuteriHalf-LifeGastric EmptyingAnimal FeedEnteroendocrine CellsAnti-Bacterial AgentsRandom AllocationMetagenomeBody WeightGastrointestinal HormonesIntestinal DiseasesColony Count, MicrobialEnteritisKidneyEatingArea Under CurveInfusions, IntravenousRectumMolecular Sequence DataForeign BodiesBacteriaAbsorptionStomach NeoplasmsDrug InteractionsDigestive System DiseasesAnti-Inflammatory Agents, Non-SteroidalBrainImmunity, MucosalBiliary TractRespiratory SystemDigestive System Surgical ProceduresIntestinal NeoplasmsDietColonic NeoplasmsLung