This approach allowed them to identify broad, population-level patterns of this important tumor disease that would not be identifiable in individual studies.
From this global dataset, they identified a microbiome signature that distinguishes colorectal cancer patients from cancer-free control populations. Thanks to the meta-analysis approach, they observed that this signature is universal across age groups and geographic regions, meaning that cancer patients tend to have similar bacterial genera in their gut. At a finer taxonomic resolution, however, they found that Fusobacterium subspecies display notable geographic variation, suggesting that pathogen strain pools are shaped by local environmental factors.
Being interested in diet as a potential influence on the gut microbiome, they found that in general higher fiber intake is negatively correlated with cancer-associated microbiome profiles, and that fiber supplementation could be useful to steer the gut microbiome away from cancer-associated towards a healthy state.
The lead author of the study, Georg Zeller, summarized: “As the largest single disease meta-analysis in the microbiome field at this point in time, this paper shows the power of open science; the insights we gained would not be easy to glean from single studies.”
The article can be found here.