Analysis Of Changes Of Intestinal Microbiota After Gastric Bypass In Mice

Background:Along with the increasing of the rate of obesity and obesity-related metabolic diseases such as diabetes mellitus, the issue of how to prevent and treat these diseases had been a new hotspot. Bariatric surgery, represented by gastric bypass, had been proved to result in weight loss and improvement of glycaemia. However, the mechanism of weight loss and reduction of glycemic level after gastric bypass remains unknown. Intestinal microbiota had been proved to be associated with obesity.thus we study the dynamic changes of intestinal microbiota after gastric bypass to find new clues.Methods:Six groups of C57/BL6mice were grouped randomly as follows:2weeks (2W),1month (1M) and2months (2M) after duodenojejunal bypass (DJB) or Sham surgery. Body weight and food intake were measured daily in1month after surgery and oral glucose tolerance test (OGTT) was performed at2months after surgery. The stool specimens of mice were collect at the tome points.16S rRNA gene based real-time PCR and PCR-Denatured gradient gel electrophoresis (PCR-DGGE) were performed to assess the diversity of intestinal microbiotaResults:Compared with mice after sham surgery, mice after DJB surgery lost weight and their oral glucose absorption assessed by OGTT was significantly reduced. Real-time PCR showed that Faecalibacterium prausnitzii, Clostridium leptum subgroup and Bifidobacterium genus were significantly increased in DJB1M group and DJB2M group compared with Sham group and DJB2W group. The B/E ratio of mice after DJB was significantly increased compared with mice after Sham surgery, while the Shannon’s diversity index showed no significant difference. PCR-DGGE showed that there were significant differences in mice of2W,1M and2M after DJB, while the Sham group showed no apparent change.Conclusions:These results suggest that components of the dominant intestinal microbiota change significantly after DJB in mice, primarily the augment of Faecalibacterium prausnitzii, Clostridium leptum subgroup and Bifidobacterium genus. These changes may directly link to weight loss and reduction of glycemic level.