It’s mucus season—the time of year this sticky goo makes an appearance in the form of runny noses and phlegmy coughs. While most people are only aware of mucus when they are sick, their organs are blanketed with the stuff year-round. And, when it comes to the microbes living in our bodies, mucus is incredibly important. It provides a spatial and nutritional niche for diverse organisms to thrive, while also preventing them from getting too close to host tissues. Mucus also regulates microbial growth, metabolism and virulence, ultimately controlling the composition of microbial communities throughout the body. As such, scientists are looking at how to exploit mucus-microbe interactions to foster human health.
Mucus is found in creatures spanning the tree of life, from corals to people. In humans and other mammals, the slick goop coats epithelial tissues, including those in the mouth, lungs, gut and urogenital tract. In these regions, mucus protects cells from physical and enzymatic stress, heals wounds and selectively filters particles that can pass through to underlying tissues.








