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: 6.77). 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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    • "Of potential functional interest, we noted that CRA was associated with significantly higher abundance of fecal Proteobacteria, the phylum that includes established gut pathogens — Pseudomonas, Escherichia, Shigella, Salmonella, Serratia, Klebsiella,andHelicobacter.Ourfindings corroborate those from a prior study in Shanghai, in which fecal microbial communities differed between 47 CRA patients and 47 normal-colonoscopy patients (Chen et al., 2013). In that latter study, the abundance of Proteobacteria taxa was modestly higher with CRA (mean = 3.7% vs 3.0%), but most of the compositional difference was attributed to other bacterial taxa (Chen et al., 2013). CRA cases also had higher abundance of Proteobacteria in feces in a small study in Spain (Mira-Pascual et al., 2014) and in biopsies of unaffected rectal mucosa (Mira-Pascual et al., 2014; Shen et al., 2010). "
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    ABSTRACT: Screening for colorectal cancer (CRC) and precancerous colorectal adenoma (CRA) can detect curable disease. However, participation in colonoscopy and sensitivity of fecal heme for CRA are low. Microbiota metrics were determined by Illumina sequencing of 16S rRNA genes amplified from DNA extracted from feces self-collected in RNAlater. Among fecal immunochemical test-positive (FIT +) participants, colonoscopically-defined normal versus CRA patients were compared by regression, permutation, and random forest plus leave-one-out methods. Of 95 FIT + participants, 61 had successful fecal microbiota profiling and colonoscopy, identifying 24 completely normal patients, 20 CRA patients, 2 CRC patients, and 15 with other conditions. Phylum-level fecal community composition differed significantly between CRA and normal patients (permutation P = 0.02). Rank phylum-level abundance distinguished CRA from normal patients (area under the curve = 0.767, permutation P = 0.006). CRA prevalence was 59% in phylum-level cluster B versus 20% in cluster A (exact P = 0.01). Most of the difference reflected 3-fold higher median relative abundance of Proteobacteria taxa (Wilcoxon signed-rank P = 0.03, positive predictive value = 67%). Antibiotic exposure and other potential confounders did not affect the associations. If confirmed in larger, more diverse populations, fecal microbiota analysis might be employed to improve screening for CRA and ultimately to reduce mortality from CRC.
    Full-text · Article · Apr 2015 · EBioMedicine
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    • "Ahn et al. 2013 (1) Feces CRC Reduced bacterial diversity in CRC cases. Chen et al. 2013 (26) Feces CRC Distinct differences in fecal microbiota communities, Clostridium, Roseburia, and Eubacterium significantly less prevalent, whereas Enterococcus and Streptococcus more prevalent in the CRA group compared with healthy controls. Geng et al. 2013 (46b) Tumor/matching normal tissue of Chinese CRC patients CRC Overabundance of Fusobacterium spp., Roseburia in tumor tissues, and overrepresentation of Microbacterium, Anoxybacillus bacteria away from tumor site. "
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    ABSTRACT: The human gut is home to a complex and diverse microbiota that contributes to the overall homeostasis of the host. Increasingly, the intestinal microbiota is recognized as an important player in human illness such as colorectal cancer (CRC), inflammatory bowel diseases, and obesity. CRC in itself is one of the major causes of cancer mortality in the Western World. The mechanisms by which bacteria contribute to CRC are complex and not fully understood, but increasing evidence suggests a link between the intestinal microbiota and CRC as well as diet and inflammation which are believed to play a role in carcinogenesis.. It is thought that the gut microbiota interact with dietary factors to promote chronic inflammation and CRC through direct influence on host cell physiology, cellular homeostasis, energy regulation, and/or metabolism of xenobiotics. This review provides an overview on the role of commensal gut microbiota in the development of human colorectal cancer and explores its association with diet and inflammation. Copyright © 2012, American Journal of Physiology- Gastrointestinal and Liver Physiology.
    Full-text · Article · Mar 2015 · AJP Gastrointestinal and Liver Physiology
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    • "Ahn et al. 2013 (1) Feces CRC Reduced bacterial diversity in CRC cases. Chen et al. 2013 (26) Feces CRC Distinct differences in fecal microbiota communities, Clostridium, Roseburia, and Eubacterium significantly less prevalent, whereas Enterococcus and Streptococcus more prevalent in the CRA group compared with healthy controls. Geng et al. 2013 (46b) Tumor/matching normal tissue of Chinese CRC patients CRC Overabundance of Fusobacterium spp., Roseburia in tumor tissues, and overrepresentation of Microbacterium, Anoxybacillus bacteria away from tumor site. "
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    ABSTRACT: The human gut is home to a complex and diverse microbiota that contributes to the overall homeostasis of the host. Increasingly, the intestinal microbiota is recognized as an important player in human illness such as colorectal cancer (CRC), inflammatory bowel diseases, and obesity. CRC in itself is one of the major causes of cancer mortality in the Western World. The mechanisms by which bacteria contribute to CRC are complex and not fully understood, but increasing evidence suggests a link between the intestinal microbiota and CRC as well as diet and inflammation which are believed to play a role in carcinogenesis.. It is thought that the gut microbiota interact with dietary factors to promote chronic inflammation and CRC through direct influence on host cell physiology, cellular homeostasis, energy regulation, and/or metabolism of xenobiotics. This review provides an overview on the role of commensal gut microbiota in the development of human colorectal cancer and explores its association with diet and inflammation. Copyright © 2012, American Journal of Physiology- Gastrointestinal and Liver Physiology.
    Full-text · Article · Dec 2014 · AJP Gastrointestinal and Liver Physiology
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