Objective: The gut microbiome is thought to play an important role in the development of colorectal cancer (CRC). However, as the gut microbiome varies widely based on diet, we sought to investigate the gut microbiome changes in patients with CRC in a South Asian population. Design: The gut microbiome was assessed by 16s metagenomic sequencing targeting the V4 hypervariable region of the bacterial 16S rRNA in stool samples (n=112) and colonic tissue (n=36) in 112 individuals. Of these had CRC (n=24), premalignant lesions (n=10), healthy individuals (n=50) and in those with diabetes (n=28). Results: Overall, the relative abundances of genus Fusobacterium (p < 0.001), Acinetobacter (p < 0.001), Escherichia-Shigella (p < 0.05) were significantly higher in gut tissue, while Romboutsia (p < 0.01) and Prevotella (p < 0.05) were significantly higher in stool samples. Bacteroides and Fusobacterium, were the most abundant genera found in stool samples in patients with CRC. Patients with pre-malignant lesions had significantly high abundances of Christensenellaceae, Enterobacteriaceae, Mollicutes and Ruminococcaceae (p < 0.001) compared to patients with CRC, and healthy individuals. Romboutsia was significantly more abundant (p< 0.01) in stool samples in healthy individuals compared to those with CRC and diabetes. Conclusion: Despite marked differences in the Sri Lankan diet compared to the typical Western diet, Bacteroides and Fusobacterium species were the most abundant in those with CRC, with Prevotella species, being most abundant in many individuals. We believe these results pave the way for possible dietary interventions for prevention of CRC in the South Asian population.

中文翻译：

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南亚人群结直肠癌患者结肠组织和粪便微生物组的宏基因组分析

目的：肠道微生物群被认为在结直肠癌（CRC）的发生中发挥重要作用。然而，由于肠道微生物组因饮食而异，因此我们试图调查南亚人群中 CRC 患者的肠道微生物组变化。设计：通过针对 112 名个体粪便样本 (n=112) 和结肠组织 (n=36) 中细菌 16S rRNA V4 高变区的 16s 宏基因组测序来评估肠道微生物组。其中患有结直肠癌 (n=24)、癌前病变 (n=10)、健康个体 (n=50) 和糖尿病患者 (n=28)。结果：总体而言，肠道组织中梭杆菌属 (p < 0.001)、不动杆菌属 (p < 0.001)、埃希氏杆菌属 (p < 0.05) 的相对丰度显着较高，而伦布特氏菌属 (p < 0.01) 和普氏菌属 (p < 0.05) 的相对丰度显着较高。 0.05）在粪便样本中显着较高。拟杆菌属和梭杆菌属是结直肠癌患者粪便样本中发现的最丰富的属。与 CRC 患者和健康个体相比，癌前病变患者的 Christensenellaceae、Enterobacteriaceae、Mollicutes 和 Ruminococcaceae 丰度显着升高 (p < 0.001)。与 CRC 和糖尿病患者相比，健康个体粪便样本中的 Romboutsia 含量显着更高 (p< 0.01)。结论：尽管斯里兰卡饮食与典型西方饮食存在显着差异，但拟杆菌属和梭杆菌属在 CRC 患者中最为丰富，而普氏菌属在许多个体中最为丰富。我们相信这些结果为南亚人群预防结直肠癌的可能饮食干预措施铺平了道路。