Meta-analysis reveals microbiome signatures for colorectal cancer that are universal across age groups and sequencing methods

Numerous studies have linked gut microbiome alterations to colorectal cancer (CRC), but limited sample sizes and study heterogeneity have hampered cross-study comparisons and subgroup analyses. Here, we present a comprehensive single-disease gut microbiome meta-analysis based on consistently re-computed and re-analyzed shotgun and amplicon sequencing profiles (n = 6,779 samples, 27 studies). Association and machine-learning analyses delineate CRC microbiome signatures, which are robustly generalizable across studies and sequencing approaches and nearly identical between early- and late-onset cases. Meta-analysis of the tumor-resident microbiome reveals characteristic tumor-enriched microbes in concordance with fecal signatures that are clearly detectable in early-stage tumors, although their detection in feces becomes moderately higher in late-stage and distal tumors, possibly due to dilution effects in stool. The unified fecal CRC signature inversely associates with dietary fiber intake and is modifiable by dietary interventions. Finally, genome-resolved functional analysis reveals variation in virulence factor carriage and geographic enrichment across Fusobacterium subspecies.