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

From BugSigDB
Needs review Marked as Needs review by Fatima on 2022/07/3
PMID PubMed identifier for scientific articles.
DOI Digital object identifier for electronic documents.
URI Uniform resource identifier for web resources.
Chen HM, Fang JY, Liu F, Yang L, Yu YN, Wang JL, Lin YW, Kong X, Yang CQ, Liu ZJ, Yuan YZ, Wu JX, Zhong L, Fang DC, Zou W, Fang JY
The American journal of clinical nutrition
First page:
colorectal cancer, colorectal adenoma, dietary fiber, short-chain fatty acids
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 less 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 as ChiCTR-TRC-00000123.

Experiment 1

Needs review

Curated date: 2022/05/31

Curator: Jeshudy

Revision editor(s): WikiWorks, Jeshudy


Location of subjects
Host species Species from which microbiome was sampled (if applicable)
Homo sapiens
Body site Anatomical site where microbial samples were extracted from according to the Uber Anatomy Ontology
Digestive system , Digestive tract , Lower digestive tract Alimentary system,Alimentary tract,Gastrointestinal system,Gut,Digestive system,Alimentary canal,Digestive canal,Digestive tube,Enteric tract,Gut tube,Digestive tract,Lower gastrointestinal tract,Lower GI tract,Lower digestive tract
Condition The experimental condition / phenotype studied according to the Experimental Factor Ontology
dietary fiber intakedietary fiber intake

Group 0 name Corresponds to the control (unexposed) group for case-control studies
Healthy control group (HC)
Group 1 name Corresponds to the case (exposed) group for case-control studies
Advanced colorectal adenoma group (A-CRA)
Group 1 definition Diagnostic criteria applied to define the specific condition / phenotype represented in the case (exposed) group
Patients with a diagnosis of A-CRA by pathological examination were enrolled in the A-CRA group.
Group 0 sample size Number of subjects in the control (unexposed) group
Group 1 sample size Number of subjects in the case (exposed) group
Antibiotics exclusion Number of days without antibiotics usage (if applicable) and other antibiotics-related criteria used to exclude participants (if any)
6 months

None of the patients had received systemic or oral topical corticosteroids, antibiotics, aspirin, other nonsteroidal antiinflammatory drugs (16), or health products that regulate intestinal microbiota within 6 mo before enrollment

Lab analysis

Sequencing type
16S variable region One or more hypervariable region(s) of the bacterial 16S gene
Sequencing platform Manufacturer and experimental platform used for quantifying microbial abundance

Statistical Analysis

Statistical test
Mann-Whitney (Wilcoxon)
Significance threshold p-value or FDR threshold used for differential abundance testing (if any)
Matched on Factors on which subjects have been matched on in a case-control study
age, sex

Alpha Diversity

Shannon Estimator of species richness and species evenness: more weight on species richness
Chao1 Abundance-based estimator of species richness

Signature 1

Reviewed Marked as Reviewed by Rimsha on 2022/05/4

Curated date: 2022/05/31

Curator: Jeshudy

Revision editor(s): WikiWorks, Jeshudy

Source: Table 4

Description: Significant differences in some genera identified between the HC (n = 47) and A-CRA (n = 47) groups

Abundance in Group 1: increased abundance in Advanced colorectal adenoma group (A-CRA)

NCBI Links

Revision editor(s): WikiWorks, Jeshudy