Table 1.
Summary of 16rRNA pyrosequencing studies involving colorectal cancer (CRC) and control specimens addressing microbial community structure.
| Authors (year) | Study subjects (N) | Type of specimens | 16S rRNA region | Beta diversity | Alpha diversity | Overrepresentation | Underrepresentation |
|---|---|---|---|---|---|---|---|
| Sobhani et al (2011)8 | CRC (60), colonoscopy control (119) | Stool | V3–V4 | PCA | – | Bacteroides/Prevotella | |
| Ahn et al (2013)13 | CRC (47), surgical control (94) | Stool | V3–V4 | – | Shannon index down in CRC | Fusobacterium, Porphyromonas | Clostridia |
| Wang et al (2012)9 | CRC (46), healthy volunteers (56) | Stool | V3 | PCA | No difference in diversity and evenness | Porphyromonas, Escherichia/Shigella, Enterococcus, Streptococcus, Peptostreptococcus | Bacteroides, Roseburia, Alistipes, Eubacterium, Parasutterella |
| Wu et al (2013)10, 65 | CRC (19), healthy volunteers (20) | Stool | V3 | PCoA | No difference in diversity and richness | Bacteroides species Fusobacterium Campylobacter species | Faecalibacterium, Roseburia |
| Weir et al (2013)15 | CRC (11), healthy volunteers (10) | Stool | V4 | – | No difference in diversity and richness | Akkermansia muciniphila | Bacteroides, Prevotella, Ruminococcus |
| Chen et al (2012)14 | CRC (46), healthy volunteers (56) | Stool, rectal swab, cancer tissue, adjacent (2–5 cm and 10–20 cm apart) normal mucosa | V1–V3 | – | Shannon index down in CRC tissue vs paired mucosa 10–20 cm apart | Lactobacillales (tumor), Erysipelotrichaceae, Prevotellaceae, Coriobacteriaceae (stool) | Faecalibacterium (tumor) |
| Mira-Pascual et al (2015)7 | CRC (7), adenoma (11), healthy volunteer (10) | Tissue (tumor or rectal mucosa), stool | V1–V3 | PCoA (tissue) | Richness up in cancer tissue | Enterobacteriaceae (cancer tissue) | |
| Geng et al (2013)11 | CRC (8) | Paired tissue (cancer, normal) | V1–V2 | PCoA | Richness up in cancer | Roseburia | Microbacterium, Anoxybacillus |
| Geng et al (2014)12 | CRC (8), adenoma (10), healthy volunteer (10) | Normal and tumor tissue | V1–V2 | PLS-DA | – | Streptococcus, Porphyromonas, Veillonella (cancer vs control) | |
| Kostic et al (2012)16 | CRC (95) | Paired tissue (cancer, normal) | V3–V5 | – | No difference in richness | Fusobacterium | Bacteroides, Clostridia, Faecalibacterium |
PCA: Principal component analysis; PCoA: Principal coordinate analysis; PLS-DA; Partial least square discriminant analysis.