Chinese Academy of Sciences Jun 26 2026 Reviewed Over the past two decades, high‑throughput sequencing has dramatically expanded our understanding of the gut microbiome's composition. However, most studies have simply listed which bacteria are present in colorectal cancer (CRC) patients, without explaining how they actually function. The field now faces major analytical hurdles: microbiome data are compositional (a change in one microbe forces apparent changes in all others), extremely sparse (