Ever wonder why we make snot? Mucus lines our respiratory and gastrointestinal tracts, acting as a sticky glue that traps unwanted substances before they can get into the body. However, research from Jeremy Barr’s lab in Melbourne, Australia has shown that there might be a lot more to the story of snot. Barr and his team have found that mucus contains a far higher concentration of bacteriophages – bacteria-killing viruses – than the surrounding tissue. These bacteriophages might be protecting the underlying human cells from invasion and infection by harmful bacteria, playing underappreciated roles as disease-fighters.

Traditionally, it was thought that these bacteria-killing viruses really only interact with bacteria, and not human cells. However, Barr’s latest research suggests that it may be possible for bacteriophages to be transported in mucus to our inner organs and subsequently absorbed by the human cells that line our gut, lungs, and even our brains. In the lab, researchers could spot bacteriophages encased inside these different human cell types, though they do not yet understand how the bacteriophages were able to get there in the first place.

This research raises the possibility that there might be an entire army of bacteriophages within us – an entire “phageome” – quietly fighting disease. There are many diseases that are associated with an imbalance of bacterial communities within our bodies, ranging from irritable bowel disease to diabetes. If scientists can understand how to recruit this phageome army to fight these bad bacteria, they might be able to treat many human diseases.

Popular news article: Do bacteriophage guests protect human health? – Science 

Original science article: Bacteriophage Transcytosis Provides a Mechanism To Cross Epithelial Cell Layers – mBio

Managing correspondent: Radhika Agarwal