Mind the Gap: Bridging the Divide from Sequencing Data to Empiric Phenotypes in the Human Gut Microbiota

The gut microbiome exerts a powerful influence on human health and disease. Elucidating the underlying mechanisms of the microbiota's influence is hindered by the immense complexity of the gut microbial community and the glycans they forage. Despite a wealth of genomic and metagenomic sequencing information, there remains a lack of informative phenotypic measurements. Pudlo NA, Urs K, Crawford R, Pirani A, et al. (mSystems 7: e00947-21, 2022, https://doi.org/10.1128/msystems.00947-21) decode this complexity by introducing a scalable assay to measure specific carbohydrate utilization in the dominant microbiota phylum Bacteroidetes. The results reveal a mosaic structure of glycan utilization, both genetic and functional, underpinning niche construction in the human gastrointestinal tract. This Commentary highlights the significance of their findings in connection to the field's growing appreciation for competition, cooperation, and horizontal gene transfer in shaping the highly complex microbial community.