Bile acids are critical components of the gastrointestinal tract that link the gut microbiota to hepatic and intestinal metabolism and therefore influence gastrointestinal motility, intestinal permeability, and carcinogenesis. The gut microbiota regulates bile acid production and signalling via the biotransformation of intestinal bile acids to unconjugated and secondary forms that readily activate bile acid receptors. Bile acids are also ligands for the G protein-coupled bile acid receptor 1 (TGR5) and for the nuclear hormone receptor farnesoid X receptor (FXR). The profiles of bile acids and gut microbiota influence each other; bile acids can modulate microbiota composition, which in turn regulates the size and composition of the bile acid pool. Disruption of bile acid–microbiota crosstalk promotes inflammation and a gastrointestinal disease phenotype, which can contribute to the development of gastrointestinal cancers, including colorectal cancer and hepatocellular carcinoma (HCC). This presentation will discuss our recent population and animal studies on the gut microbiome – bile acid crosstalk and its role in the development of HCC. We would also highlight that the modulation of gut microbiota and bile acid profiles holds promise as a novel therapeutic approach for the treatment of gastrointestinal cancers and represents the next frontier for gastrointestinal cancer research.

结直肠癌是一种重要的全球性癌症。元基因组学研究揭示了结直肠癌患者的微生物变化，功能性研究阐明了几种细菌在结直肠癌发生中的作用，包括核梭杆菌，某些大肠杆菌和脆弱拟杆菌。最近的研究也指出，肠道微生物群对于癌症治疗亦非常重要，尤其是在免疫疗法的功效。这些发现为利用这些微生物进行临床应用提供了新的机会。 在众多的临床应用中，生物标志物是其中最具潜力的一环，是诊断疾病存或其严重程度的指标。鉴于结直肠癌持续上升及早期癌症的可治疗性，发展一个精确的非侵入性测试有重大的公共卫生意义。肠道菌群为结直肠癌筛查和疾病预测提供了丰富的生物标志物来源。在这次分享中，我将回顾结肠直肠癌微生物群的最新文献，并讨论肠道微生物群在结肠直肠癌诊断和治疗中的临床应用。

It is well-established that biofilms are critical for the pathogenesis of many bacterial infections, such as urinary tract infections and dental caries. More recently, biofilms have also been implicated in intestinal diseases such as colorectal cancer and inflammatory bowel disease, where mucosal-associated polymicrobial communities harvested from diseased colon worsens disease in animal models. Despite these studies, the presence of biofilms in the intestinal tract has been controversial. In this talk, I will review current evidence for biofilm formation in intestinal diseases and discuss my current model for investigating determinants of bacterial biofilm formation.