A Comparative Study Of Intestinal Microbiota Alteration In Obesity Patients After LSG And LRYGB

Aims:To explore and compare the intestinal microbiota composition affected by the two most widely used procedures of bariatric surgery,Laparoscopic Sleeve Gastrectomy(LSG)and Laparoscopic Roux-en-Y Gastric Bypass(LRYGB),in obesity patients.Methods:We identified the obesity patients who underwent primary bariatric surgery,including LSG and LRYGB,from July 2016 to August 2017 in the First Affiliated Hospital of Jinan University.Stool samples were collected from obese patients before(n=80)and after surgery(n=44).The samples were divided into pre-LSG(n=53),pre-LRYGB(n=27),post-LSG(n=31)and post-LRYGB(n=13)groups.After DNA extraction,16S rDNA(V3+V4 regions)sequencing was completed on Illumina HiSeq 2500 sequencing platform.Sequencing data was clustered as OTUs(Operational Taxonomic Units)at 97%similarity level,annotated to Silva ribosomal RNA database,and microbiota analyses were conducted.Results:80 patients were included and 44(55.0%)of them completed the follow-up(8.18±4.13months).After bariatric surgery,Shannon Index significantly increased,indicating that bariatric surgery rose intestinal microbiota richness and evenness.Metastats analysis showed that 3 phyla and 17 genera altered after surgery in total.58.82%of those altered genera belonged to phylum Firmicutes.BMI decreased from 37.66±6.07 kg/m~2 to 26.43±4.45 kg/m2 after LSG and from46.24±15.30 kg/m~2 to 34.42±10.99 kg/m~2 after LRYGB.No statistical difference was observed on Shannon index between patients undergoing LSG or LRYGB.Both procedures increased intestinal microbiota richness and evenness in obesity patients.Metastats analysis showed that 14genera altered after LSG while 4 altered after LRYGB,in which the relative abundance of 2genera,Gemella and Streptococcus,were increased in both procedures.Conclusion:Both LSG and LRYGB altered the composition of intestinal microbiota in Chinese obesity patients,particularly increased the richness and evenness of microbiota.Genera belong to phylum Firmicutes were the most influenced by bariatric surgery.The procedure of LSG showed more pronounced alteration of the abundance in microbiota than that observed in LRYGB.