Cheng Wenyue, Li Fan, Yang Rongcun
Translational Medicine Institute, Affiliated Tianjin Union Medical Center of Nankai University, Nankai University, Tianjin, China.
Department of Immunology, Nankai University School of Medicine, Nankai University, Tianjin, China.
Gastro Hep Adv. 2024 Jun 7;3(6):855-870. doi: 10.1016/j.gastha.2024.05.012. eCollection 2024.
Colorectal cancer (CRC) is one of the most common cancers worldwide. The occurrence and development of CRC are related to multiple risk factors such as gut microbiota. Indeed, gut microbiota plays an important role in the different phases of colorectal cancers (CRCs) from oncogenesis to metastasis. Some specific bacteria such as associated with CRCs have been found. However, recently identified bile acid and tryptophan metabolites as well as short chain fatty acids (SCFAs), which are derived from gut microbiota, can also exert effects on the CRCs such as that SCFAs directly inhibit CRC growth. Importantly these metabolites also modulate immune responses to affect CRCs. They not only act as tumor inhibiting factor(s) but also promotor(s) in the occurrence, development, and metastasis of CRCs. While gut microbiota metabolites (GMMs) inhibit immunity against CRCs, some of them also improve immune responses to CRCs. Notably, GMMs also potentially affect the shaping of immune-privileged metastatic niches through direct roles or immune cells such as macrophages and myeloid-derived suppressive cells. These findings offer new insights for clinical application of gut microbiota in precise and personalized treatments of CRCs. Here, we will mainly discuss direct and indirect (via immune cells) effects of GMMs, especially SCFAs, bile acid and tryptophan metabolites on the occurrence, development and metastasis of CRCs.
结直肠癌（CRC）是全球最常见的癌症之一。CRC的发生和发展与多种风险因素有关，如肠道微生物群。事实上，肠道微生物群在结直肠癌（CRCs）从肿瘤发生到转移的不同阶段都发挥着重要作用。已经发现了一些与CRCs相关的特定细菌。然而，最近发现的源自肠道微生物群的胆汁酸和色氨酸代谢产物以及短链脂肪酸（SCFAs），也可以对CRCs产生影响，例如SCFAs直接抑制CRC生长。重要的是，这些代谢产物还调节免疫反应以影响CRCs。它们不仅在CRC的发生、发展和转移中充当肿瘤抑制因子，也充当促进因子。虽然肠道微生物群代谢产物（GMMs）抑制针对CRCs的免疫，但其中一些也能改善对CRCs的免疫反应。值得注意的是，GMMs还可能通过直接作用或通过巨噬细胞和髓系来源的抑制细胞等免疫细胞影响免疫特权转移微环境的形成。这些发现为肠道微生物群在CRCs的精准和个性化治疗中的临床应用提供了新的见解。在此，我们将主要讨论GMMs，尤其是SCFAs、胆汁酸和色氨酸代谢产物对CRCs发生、发展和转移的直接和间接（通过免疫细胞）影响。
