Gut mycobiome alterations in obesity in geographically different regions.

The gut fungi play important roles in human health and are involved in energy metabolism. This study aimed to examine gut mycobiome composition in obese subjects in two geographically different regions in China and to identify specific gut fungi associated with obesity. A total of 217 subjects from two regions with different urbanization levels [Hong Kong (HK): obese, n = 59; lean, n = 59; Kunming (KM): obese, n = 50; lean, n = 49. Mean body mass index (BMI) for obesity = 33.7] were recruited. We performed deep shotgun metagenomic sequencing on fecal samples to compare gut mycobiome composition and trophic functions in lean and obese subjects across these two regions. The gut mycobiome of obese subjects in both HK and KM were altered compared to those of lean subjects, characterized by a decrease in the relative abundance of Nakaseomyces, Schizosaccharomyces pombe, Candida dubliniensis and an increase in the abundance of Lanchanceathermotolerans, Saccharomyces paradox, Parastagonospora nodorum and Myceliophthorathermophila. Reduced fungal - bacterial and fungal - fungal correlations as well as increased negative fungal-bacterial correlations were observed in the gut of obese subjects. Furthermore, the anti-obesity effect of fungus S. pombe was further validated using a mouse model. Supplementing high-fat diet-induced obese mice with the fungus for 12 weeks led to a significant reduction in body weight gain (p < 0.001), and an improvement in lipid and glucose metabolism compared to mice without intervention. In conclusion, the gut mycobiome composition and functionalities of obese subjects were altered. These data shed light on the potential of utilizing fungus-based therapeutics for the treatment of obesity. S. pombe may serve as a potential fungal probiotic in the prevention of diet-induced obesity and future human trials are needed.

Accuracy of hiatal hernia diagnosis in bariatric patients: Preoperative endoscopy versus intraoperative reference.

BACKGROUND AND AIM: Obesity is becoming increasingly prevalent in Asia. Bariatric surgery in the region is growing in popularity to reflect increasing demand. Hiatal hernia (HH) is common among the obese population. There is a lack of evidence comparing preoperative endoscopy against intraoperative findings as a standard of reference for HH diagnosis. METHODS: This was a retrospective analysis of a bariatric procedure database from a single tertiary teaching hospital and high-volume endoscopy center. Electronic medical records were reviewed. Endoscopy results were compared to intraoperative findings, and subgroup analysis of >2 cm hernias was performed. Sensitivity, specificity, predictive values, likelihood ratios, and global diagnostic test accuracy were calculated. RESULTS: A total of 434 patients were eligible for this study, of which HH was detected in 37 patients (prevalence rate 8.55%). Mean age was 41.51 ± 11.07 years, and body mass index was 39.37 ± 5.67 kg/m2. Endoscopy sensitivity was 75.68% (95% confidence interval, 58.80-88.23%) and specificity 91.44% (88.24-94.00%). Positive likelihood ratio was 8.53 (6.11-12.79) and negative likelihood ratio 0.27 (0.15-0.47). Positive predictive value was 45.16% (36.27-54.38%) and negative predictive value 97.58% (95.80-98.62%). Accuracy of endoscopy for preoperative HH diagnosis was 90.09% (86.89-92.74%). CONCLUSION: Endoscopy can have a high diagnostic accuracy of preoperative HH diagnosis in obese Asian patients using intraoperative diagnosis as the reference standard.