Article

Decreased dietary fiber intake and structural alteration of gut microbiota in patients with advanced colorectal adenoma

Division of Gastroenterology and Hepatology, Renji Hospital, Shanghai Jiao-Tong University School of Medicine, Shanghai Institution of Digestive Disease
American Journal of Clinical Nutrition (Impact Factor: 6.92). 04/2013; 97(5). DOI: 10.3945/ajcn.112.046607
Source: PubMed

ABSTRACT BACKGROUND: Accumulating evidence indicates that diet is one of the most important environmental factors involved in the progression from advanced colorectal adenoma (A-CRA) to colorectal cancer. OBJECTIVE: We evaluated the possible effects of dietary fiber on the fecal microbiota of patients with A-CRA. DESIGN: Patients with a diagnosis of A-CRA by pathological examination were enrolled in the A-CRA group. Patients with no obvious abnormalities or histopathological changes were enrolled in the healthy control (HC) group. Dietary fiber intake was assessed in all patients. Short-chain fatty acids (SCFAs) in feces were detected by gas chromatography. The fecal microbiota community was analyzed by 454 pyrosequencing based on 16S ribosomal RNA. RESULTS: Lower dietary fiber patterns and consistently lower SCFA production were observed in the A-CRA group (n = 344). Principal component analysis showed distinct differences in the fecal microbiota communities of the 2 groups. Clostridium, Roseburia, and Eubacterium spp. were significantly more prevalent in the A-CRA group (n = 47) than in the HC group (n = 47), whereas Enterococcus and Streptococcus spp. were more prevalent in the A-CRA group (n = 47) (all P < 0.05). Butyrate and butyrate-producing bacteria were more prevalent in a subgroup of HC subjects with a high fiber intake than in those in both the low-fiber HC subgroup and the high-fiber A-CRA subgroup (all P < 0.05). CONCLUSION: A high-fiber dietary pattern and subsequent consistent production of SCFAs and healthy gut microbiota are associated with a reduced risk of A-CRA. This trial was registered at www.chictr.org as ChiCTR-TRC-00000123.

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