Differences in intestinal microbiota profiling after upper and lower gastrointestinal surgery

Abstract

We aimed to investigate the long-term effects of metabolic profiles and microbiota status in patients after upper gastrointestinal (GI) surgery and lower GI surgery and compared them to a control group. In this cross-sectional study, we analyzed the occurrence of metabolic syndrome (MS) in 10 patients who underwent curative total gastrectomy with Roux-en-Y esophagojejunostomy (RYEJ) anastomosis, 11 patients who underwent curative partial colectomy with right hemicolectomy (RH), and 33 age and sex-matched controls. Fecal samples were also analyzed by a next-generation sequencing method. Compared with the control group, the occurrence of MS was significantly lower among patients who underwent total gastrectomy with RYEJ than the controls over the long-term follow-up (> 8 years; p< 0.05). Patients who received RH only had a trend of higher serum fasting glucose (p= 0.10). The diversity of the gut microbiota significantly decreased after RH in comparison with the control group and RYEJ group respectively (p < 0.05). Principal component analysis revealed significant differences between the control, RYEJ, and RH groups (p< 0.001). At the genus level, the ratio of Prevotella to Bacteroides (P/B) was significantly higher in the RYEJ group than the control group, whereas the P/B ratio was significantly lower in the RH group than the control group (p< 0.05). Early gastric cancer patients who received total gastrectomy with RYEJ had a lower occurrence of MS than the controls, while early CRC patients who received RH were associated with a higher serum fasting glucose than the controls during long-term follow-up. In parallel with the metabolic differences, the P/B ratio was also significantly altered in patients after upper and lower GI surgery.