Species sorting and community-level functionality in a natural microbial community - Experiments using a traditional fermented dairy ecosystem model from Zambia

Natural microbial communities occupy diverse environments and perform essential functions, including supporting soil health, contributing beneficial compounds to food, and promoting human gut health. These communities, however, are frequently exposed to environmental change, resulting in an unpredictable shifts in both composition and function. We tested this idea using a self-assembled microbial community derived from a traditional fermented milk produced in a low-income setting in Zambia. Specifically, we examined how a shared starting community responded to different environments, represented by substrate variation, under natural conditions at differing period, and how these changes related to community function. Additionally, we assessed how variation in the geographical location of traditional milk processors influenced microbial community outcomes and associated functions. Collectively, our findings provided insights into how environmental change shapes microbial community structure–function relationships and demonstrated the potential of traditional fermented milk as a resource for diversifying fermented milk types, including applications relevant to infant nutrition and the management of malnutrition in low-income settings.