Illustration by Benjamin Arthur for NPR

The mammalian gut is host to a wide variety of microbiota that are key to healthy metabolism. Beginning from early periods in mammalian life, these protozoa, archaea, eukaryotes, viruses, and bacteria colonize the mammalian gut, forming a symbiotic relationship that lasts through the organism’s life cycle.

With the advent of genetic tools, computational power, and sequencing technologies, researchers have been able to dive deeper into…