In the moist, dark microbial rainforest of the intestine, hundreds of species of microorganisms interact with each other and with the cells of the host animal to get the resources they need to survive and thrive.
Though there's a lot of competition in this vibrant ecosystem, collaboration is valued too. A new study on the crosstalk between microbes and cells lining the gut of mice shows just how cooperative this environment can be.
One of the main ways that hosts manage their interactions with microbes is by carefully controlling the genes that their cells use. Duke University researchers, with colleagues from UNC-Chapel Hill and Stanford, have found that the host genes in the intestine are poised to respond to microbes, and that microbes signal to the host to determine which genes respond.
"The intestine has a tough assignment – it has to allow for digestion and absorption of dietary nutrients while also carefully harboring and managing the teeming microbial community within," said John Rawls, PhD, associate professor of medicine (Gastroenterology) and molecular genetics and microbiology in the Duke School of Medicine.
"These physiologic responsibilities and microbial interactions vary at different places along the gut." Molecules produced on demand by the host's genes have lots of different jobs that might help or hurt the bugs: immune responses, digestive enzymes, physiological "climate control" and metabolism, among others. In some cases, the microbes might even be calling in immune system attacks on their competitors, Rawls said. "Good fences make good neighbors."
The study appears Aug. 7 in the journal Genome Research. Read more about the study.