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.

Antibiotic-resistant Cutibacterium acnes and dysbiosis of the skin microbiome are of increasing concern in acne treatment. Enterococcus faecalis, a widely used probiotic, has shown benefits for acne treatment by exerting antimicrobial activity against C. acnes. Therefore, this study aimed to investigate the efficacy and safety of an E. faecalis CBT SL-5-extract-containing lotion in patients with mild-to-moderate acne. Twenty patients were enrolled in this randomized, placebo-controlled, split-face comparative study. Patients were treated with E. faecalis lotion on one side of the face and a vehicle lotion on the other side for 4 weeks. The efficacy outcome measures included improvement in the investigators’ assessment of acne severity, patient satisfaction, changes in skin parameters and diversity of the skin microbiome. The investigators’ assessment score was significantly improved on the test side compared to the control side, after 2 weeks (p = 0.009) and 6 weeks (p < 0.0005). However, TEWL and skin hydration were not significantly different between the two groups. The phylogenetic diversity of the skin microbiota decreased over time in the skin samples of test side. In conclusion, E. faecalis CBT SL-5 extract can be a feasible and well-tolerated option for improving acne severity and skin microbiome dysbiosis in mild-to-moderate acne patients.