A recent study (SH Wong et al. Gastroenterol 2017; 153: 1621-33) highlights the potential role of the microbiota and colorectal cancer (CRC).
In this study, the stool from either patients with CRC or control patients was gavaged into mice twice a week for 5 weeks. One group of mice had received azoxymethane (AOM) which induces neoplasia and the other group were germ-free mice. Extensive studies involving immunohistochemistry, expresssion microarray, quantitative polymerase chain reaction, immunoblot, and flow cytometry.
- Conventional, AOM-treated mice who received gavage from patients with CRC had significantly higher proportions of high-grade dysplasia (P<.05) and macroscopic polyps (P<.01)
- Among the germ-free mice fed with stool from patients with CRC, there was a higher proportion of proliferating Ki-67-positve cells
- These findings correlated with more dysbiosis in the mice who received stool from patients with CRC and with upregulation of genes involved in cell proliferation, stemness, apoptosis, angiogenesis, and invasiveness
“This study provides evidence that the fecal microbiota from patients with CRC can promote tumorigenesis in germ-free mice and mice given a carcinogen.”
My take: This study shows that microbiota clearly influence the risk of CRC. I infer from this study that this could explain the potential healthy roles of diets with more fruits and vegetables, that promote healthier microbiota as well as the potential detrimental role of diets with more processed meats.
Related study: L Liu et al. Association between Inflammatory Diet Pattern and Risk of Colorectal Carcinoma Subtypes Classified by Immune Responses to Tumor Gastroenterol 2017; 153 1517-30. Using two databases from 2 prospective cohorts with followup of 124,433 participants, inflammatory diets had a higher risk of a colorectal cancer subtype.
Related blog posts:
- Better Diet, Lower Mortality
- Colon Cancer at Younger Ages
- Diet, Meat and Colrectal Cancer
- For Increased Longevity: More Greens are Good