Illuminating gene functions in the human gut microbiome – SPP2474

Bacteria are ubiquitous and have shaped the earth’s history for billions of years – impacting every ecosystem on this planet. Yet it is only through sequencing efforts in the last couple of decades that we have begun to appreciate the tremendous diversity of bacterial species that colonise every corner of this planet. Most of these species are terra incognita – they are full of new genetic material and look nothing like the model species microbiologists have been using for decades.

This knowledge gap also applies to microbial ecosystems that are part of the human body and are intimately linked to our health, such as the human gut microbiome. It is currently estimated that approximately 4,500 different bacterial species can colonise the human gut (with 250–500 species found in each individual), 70% of which have not been cultured in isolated form. Up to 50% of their genomic material is of unknown function. Although we are aware of the importance of these gut bacteria for human health, we know little about their biology.

Understanding the unexplored functions of genes in human gut bacteria and their organisation into pathways is vital if we want to go beyond descriptive associations of the gut microbiota with human health and map the causal mechanisms, thereby unlocking its potential for therapeutic applications.