Cataloging the resident microbes and their metabolic potential in the large intestine of cattle

Cattle rely on the bacteria in their rumen and intestine to digest their plant based diet. However, that microbial community also produces the greenhouse gas methane and can contain pathogens. Despite their important roles, good and bad, much of the research into these microbes has been fragmentary. and studies on the intestine have mainly focused on the microbes' identities, rather than their metabolic capabilities. To close this gap, researchers recently examined this community using metagenome assembled genomes (MAGs) from fecal samples. MAGs are sequenced fragments of microbial DNA assembled into likely genomes by a computer. Using this data, the researchers found that bacterial families had distinct metabolic profiles compared to one another. Also, changes in the cows’ diet impacted the microbial community composition, diversity, and even potential virulence. However, the predicted metabolic enzymes remained consistent between diets; they were just produced by different microbes, meaning that the community metabolism is maintained by switching between individual microbes like replaceable cogs. While fecal MAGs are only a proxy for the dynamic microbial community in the large intestine, this study generated a broad microbial catalog that provides insight into the familial relationships and metabolic potential within this microbial community.