We have a mutualistic but complicated relationship with the collection of microbes in our gut known as the intestinal microbiome. This complex community of bacteria breaks down different food components, and releases nutrients such as vitamins and a plethora of other factors that control functions in tissues way beyond the intestinal tract. However, the sheer numbers of microbes also present a threat as they can trigger inflammation, which is thought to be at the root of many intestinal diseases, including inflammatory bowel disease, radiation-induced intestinal injury, and some cancers.

To allow the uptake of beneficial substances from the gut lumen, and at the same time prevent gut microbes from contacting the intestinal epithelial tissue surface, specialized cells called goblet cells continuously produce mucus, the slimy goo-like substance that coats the entire intestinal surface. Mucus thus far has been notoriously difficult to study: its structure quickly disintegrates in surgically removed sections of the gut, the system most often used to study mucus, and no in vitro culture system has been able to reconstitute an in vivo-like mucus layer with the natural structure seen in living intestine outside the human body. Adding to these difficulties, mucus also differs between humans and other species, different sections of the intestinal tract, and even different individuals… Continue reading.