The human large bowel is home to complex and diverse communities of bacteria (microbiota) which play important roles in health and disease. Evidence from animal studies and studies in humans suggest that intestinal bacteria may contribute to the pathogenesis of colorectal cancer (CRC), a major leading cause of cancer mortality in the United States. Potential mechanisms linking the gut microbiota and CRC are through inflammation and diet. We propose a model whereby intestinal bacteria play a prominent role in the etiology of CRC through diet, metabolism of xenobiotics and inflammation. Colonic bacteria are important in the development of gut immunity, particularly those residing on the mucosa. The goal of this study is to evaluate the relationship between mucosa-associated (adherent) bacteria and risk of colorectal adenomas. We also assess the role of inflammation and diet in the bacteria-adenoma association.
- Characterize adherent bacteria communities in biopsies from subjects with and without adenomas.
- Determine whether the adherent bacteria communities differ between subjects with adenomas and those without adenomas.
- Evaluate the associations of adherent bacteria and local mucosal inflammation among subjects with and without adenomas.
- Assess the association between mucosal bacteria profiles and diet in relation to colorectal adenomas.
Our current findings indicate that alterations in the gut bacterial community composition are associated with colorectal adenomas. In addition, we observed that elevated levels of endotoxin in the systemic circulation could be a potential marker of adenoma risk. To date, our results provide important insights into the role of bacteria and bacterial products on the risk of colorectal adenomas. This study could help identify bacterial signatures for adenomas and also point to ways to manipulate the microbiota to prevent colorectal cancer as well as identify individuals at high risk.
Title Image Credit: http://www.secondgenome.com/wp-content/uploads/2012/04/PRinc_AJ477A-640×360.jpg
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