Functional Divergence in Gut Clostridia from Hadza Hunter-Gatherers Reveals Diet-Adapted Metabolic Machinery That Shapes Gut Ecology

The study of gut microbiomes from traditional populations, like the Hadza hunter-gatherers of Tanzania, sheds light on the changes that occur in industrialized microbiomes. Even though these populations have distinct lifestyles, many commensal gut species are common to both industrialized and non-industrialized groups. This leads to the question of whether these shared species, despite living in different environments, have differences in their functional abilities.

By combining metagenomics, culturomics, and in vivo models, researchers have identified divergences within prevalent gut species shared between Hadza and industrialized populations. Specifically, they examined Clostridia, a class of bacteria, and one of its members, Dorea longicatena, which is found across different human populations regardless of lifestyle.

Through studying strains of D. longicatena from both Hadza and industrialized individuals, scientists found metabolic pathways in Hadza strains that are specifically beneficial for utilizing plant-derived pectic polysaccharides. They also discovered that introducing this Hadza-specific polysaccharide-utilization machinery into a model of an industrialized microbiota can alter the overall metabolite profile of the gut.

Overall, the research highlights significant functional differences within gut bacteria that are shared across different lifestyles. This discovery not only provides a way to identify strains and pathways that are responsive to diet but also helps to fill in the gaps of ecological and metabolic functions that are often underrepresented in industrialized microbiotas.