The Impact Of Exclusive Enteral Nutrition On Gut Microflora In Induction And Maintenance Therapy For Crohn's Disease

BackgroundCrohn's disease(CD)is a idiopathic,chronic,incurable inflammatory disorder.It's exact etiology is unknown,and both heredity and exposure to bacteria have been implicated.The relationship between gut microflora and host is being widely investigated.Exclusive enteral nutrition bring satisfactory clinical outcome in treatment of CD.EEN can effectively induce and maintain remission for CD,while the mechanism is unclear.Previous studies proved that EEN can change the microbial composition and improve function of gut microflora,while the further illumination is deficiency.PurposeThis study aim to compare the characteristic of gut microbiota between CD patients and healthy control.When applying EEN in inducing and maintaining therapy for CD,we investigated the impact of EEN on gut microflora dynamically and continuously and revealed the exact change of gut microflora after EEN therapy.Methods and resultsIn comparison of gut microflora between CD patients and healthy control,we collected stool sample from 10 healthy control and 14 treatment-naive CD patients,and analyzed microflora through sequencing the V4 region of 16sDNA.We found remarkable difference in flora composition,specific bacteria between CD patients and healthy control,and flora diversity of CD patients decrease strikingly.Combined with studies from western country,we found there is regional features of gut microflora of CD patients.When comparing the impact of EEN with corticosteroid on gut microflora in induction treatment of CD,we enrolled 10 CD patients for each group and 8 patients for each group achieved remission.Both corticosteroid and EEN achieved satisfactory clinical effect.The results suggested that both corticosteroid and EEN change the flora composition dramatically and improve the flora diversity.For certain flora group and specific specie,corticosteroid and EEN play opposite roles.In contrastive analysis with our last study,the composition and proportion of gut microflora had a tendency to be normalized like healthy control.We followed up 6 CD patients who received EEN maintenance treatment after EEN induction treatment,stool was sampled and clinical effect was evaluated at follow-up point punctually.After 3 month follow-up,we found EEN can maintain remission effectively.The disease activity was well controlled,and the inflammatory indicators decreased,and the nutritional status was improved.We found EEN have a tender effect on the change of gut microflora in maintenance therapy than in induction therapy.After EEN maintenance remission treatment,the composition and proportion of gut microflora tended to be normalized continuously,and the flora diversity increased gradually.ConclusionThe gut microflora of CD patients varies from healthy control dramatically in flora composition and proportion specific bacteria;the diversity significantly decrease.Both EEN and corticosteroid can induce active disease into remission effectively.Although both corticosteroid and EEN changed the gut microflora and improved the diversity,corticosteroid act stronger,and for certain flora group and specific specie,corticosteroid and EEN have opposite role.No matter EEN is applied for induction therapy or maintenance therapy,EEN can normalize the disorder composition and proportion of gut microflora continuously,and increase the flora diversity.This is maybe one of mechanism for EEN to induce and maintain CD remission.