Association between the Blautia/Bacteroides Ratio and Altered Body Mass Index after Bariatric Surgery

Background@#Current evidence support that the gut microbiota plays a potential role in obesity. Bariatric surgery can reduce excess weight and decrease the risk of life-threatening weight-related health problems and may also influence gut microbiota. In this study, we aimed to investigate the changes in gut microbiota before and after bariatric surgery and evaluate the association of the gut microbial shift and altered body mass index (BMI) after bariatric surgery. @*Methods@#Between January 2019 and July 2020, stools from 58 patients scheduled for bariatric surgery were collected. Six months after bariatric surgery, stools from 22 of these patients were re-collected, and the changes in gut microbiota before and after bariatric surgery were evaluated. In addition, the differences in gut microbiota between patients with severe obesity (BMI >35 kg/m2, n=42) and healthy volunteers with normal BMI (18.8 to 22.8 kg/m2, n=41) were investigated. @*Results@#The gut microbiota of patients who underwent bariatric surgery showed increased α-diversity and differed β-diversity compared with those before surgery. Interestingly, Blautia was decreased and Bacteriodes was increased at the genus level after bariatric surgery. Further, the Blautia/Bacteroides ratio showed a positive correlation with BMI. To validate these results, we compared the gut microbiota from severely obese patients with high BMI with those from healthy volunteers and demonstrated that the Blautia/Bacteroides ratio correlated positively with BMI. @*Conclusion@#In the gut microbial analysis of patients who underwent bariatric surgery, we presented that the Blautia/Bacteroides ratio had changed after bariatric surgery and showed a positive correlation with BMI.

Short-term outcome of bariatric surgery on nonalcoholic fatty liver disease: a Korean perspective

Purpose@#Obesity is associated with nonalcoholic fatty liver disease, one of the most common causes of chronic liver disease.We aimed to demonstrate the effectiveness of bariatric surgery for hepatic steatosis and fibrosis in Korean patients. @*Methods@#A total of 32 consecutive patients were enrolled in this study. Hepatic steatosis and liver fibrosis were assessed before surgery and 6 months after surgery using transient elastography and serologic panels. @*Results@#Thirteen patients (40.6%) were male and 19 (59.4%) were female, with a mean age of 39.3 ± 11.3 years. The body mass index was significant at the 6th month: 39.1 ± 6.7 and 30.3 ± 4.7 kg/m2 (P < 0.001), respectively. The mean preoperative controlled attenuation parameter and liver stiffness measurement values were 325.4 ± 55.9 dB/m and 7.4 ± 4.8 kPa, respectively, before surgery, and they decreased to 267.1 ± 45.1 dB/m and 5.3 ± 2.3 kPa, respectively, 6 months postoperatively (P < 0.001, respectively). @*Conclusion@#These results suggest that bariatric surgery is associated with a significant improvement in liver steatosis and fibrosis. Bariatric surgery has a beneficial effect on nonalcoholic fatty liver disease in patients with morbid obesity in Korea.