Genetically Predicted Causal Effects of Gut Microbiota and Gut Metabolites on Digestive Tract Cancer: A Two-Sample Mendelian Randomization Analysis.

Background: Evidence from numerous observational studies and clinical trials has linked gut microbiota and metabolites to digestive tract cancer. However, the causal effect between these factors remains uncertain. Methods: Data for this study were obtained from the MiBioGen, TwinsUK Registry, and FinnGen (version R8). Two-sample Mendelian randomization analysis with inverse variance weighting method was primarily used, and the results were validated by heterogeneity analysis, pleiotropy test, and sensitivity analysis. Results: At P < 5 × 10-8, our analysis identified four gut microbiotas as risk factors for digestive tract cancer and six as risk factors for colorectal cancer. Conversely, one gut microbiota exhibited protection against bile duct cancer, and two showed protective effects against stomach cancer. At P < 1 × 10-5, our investigation revealed five, six, three, eight, eight, and eight gut microbiotas as risk factors for esophageal, stomach, bile duct, liver, pancreatic, and colorectal cancers, respectively. In contrast, four, two, eight, two, two, and five gut microbiotas exhibited protective effects against these cancers. Additionally, GABA, a metabolite of gut microbiota, displayed a significant protective effect against colorectal cancer. Conclusion: In conclusion, specific gut microbiota and metabolites play roles as risk factors or protective factors for digestive tract cancer, and a causal relationship between them has been established, offering novel insights into gut microbiota-mediated cancer development.

Detection of the common bile duct in difficult bile duct exploration using indocyanine green fluorescence imaging: A case report.

We describe two cases using indocyanine green (ICG) fluorescence imaging for visualization of the common bile duct (CBD) in patients with difficult Bile duct exploration (BDE) due to extensive dense adhesions around the hepatoduodenal ligament. The CBD was rapidly detected under fluorescence guidance without excessive dissection of extensive dense adhesions. It is illustrated that the use of ICG fluorescence imaging is effective and feasible for detecting the CBD and thus we highly recommend this method during difficult BDE.