Table 1.

Summary of epidemiologic studies examining the association of the fecal microbiome with colorectal cancer

Author, Year	Country	Study Design	Sample Size	Main Findings Comparing Cases to Controls
Scanlan, 20083	Belgium	Case-control	20 cancers / 20 polyps / 20 controls	↑ diversity of the Clostridium leptum and C. coccoides subgroups
Sobhani, 20114	France	Case-control	60 cancers / 119 controls	↑ Bacteroides/Prevotella
Wang, 20125	China	Case-control	46 cancers / 56 controls	↑ Bacteroides fragilis and opportunistic pathogens; ↓ butyrate-producing bacteria
Ahn, 20136	USA	Case-control	47 cancers / 94 controls	↓ diversity; ↓ Clostridia; ↑ Fusobacterium, Porphyromonas;
Zackular, 20147	USA	Case-control	30 cancers / 30 adenomas / 30 controls	↑ Bacteroides fragilis, Fusobacterium, Porphyromonas; ↓ butyrate-producing bacteria
Zeller, 20148	France	Case-control	91 cancers / 42 adenomas / 358 controls	↑ Bacteroidetes, Fusobacteria and Proteobacteria; ↓ Actinobacteria and Firmicutes
Feng, 20159	Austria	Case-control	41 cancers / 42 adenomas / 55 controls	↑ B. dorei, B. vulgatus, E. coli, Fusobacterium; ↓ Lactobacillus and Bifidobacterium
Vogtmann, 201610	USA, France	Case-control	52 cancers / 52 controls	↑ Fusobacterium, Porphyromonas, Clostridia
Yu, 201711	Denmark, France, Austria	Case-control	74 cancers / 54 controls	↑ Peptostreptococcus stomatis, F. nucleatum, Parvimonas micra, Solobacterium moorei
Shah, 201712	Multiple countries	Pooled analysis of case-control studies	195 cancers / 79 adenomas / 235 controls	↑ Parvimonas micra ATCC 33270,Streptococcus anginosus, yet-to-becultured members of Proteobacteria
Liang, 201713	China	Case-control	203 cancers / 236 controls	↑ F. nucleatum, Clostridium hathewayi; ↓ B. clarus
Flemer, 201714	Ireland	Case-control	43 cancers / 37 controls	↓ Lachnospiraceae incertae sedis and Coprococcus