An altered composition of fecal microbiota, organic acids, and the effect of probiotics in the guinea pig model of postoperative ileus

Background: The aim of this study is to investigate the altered composition of fecal microbiota, organic acids, and the effect of probiotics in the guinea pig model of the postoperative ileus (POI). Methods: A laparotomy with cecal manipulation was performed to induce POI in guinea pigs. Fecal pellets were collected before the operation (the baseline) and 1, 3, and 5 days after the operation. The extracted fecal DNA was amplified and sequenced using the Illumina MiSeq sequencing system. The same POI procedures were performed after oral pretreatment of the probiotics for 7 days before operation. The effect of the probiotics on the selected taxa and fecal acetate were evaluated, as were the butyrate levels. The colonic transit was assessed by measurement of the fecal pellet output. Key Results: The communities of the baseline and POI groups indicated significantly distinct composition. The genera Bifidobacterium and Lactobacillus were more abundant in the baseline group compared with the POI groups, and Bacteroides and Blautia were more abundant in the POI groups. Decreased abundances of the species Bifidobacterium bifidum and Bifidobacterium longum after the POI procedure were significantly increased in the probiotics group. The decreased fecal butyrate level after the POI procedure was significantly increased, and colonic transit was significantly improved in the probiotics group. Conclusions and Inferences: POI induces gut bacterial dysbiosis. Moreover, pretreatment of probiotics before operation restores the beneficial bacterial species, butyrate production, and bowel movement. The modulation of gut microbiota may help the treatment and prevention of POI.