Distinct communities of bacteria living in and on many parts of our bodies play a role in human health, but what about noses? Bioengineer Sarah Lebeer of the University of Antwerp became interested in the question when her mother underwent surgery to relieve lifelong problems with chronic rhinosinusitis, inflammation of the membranes that line the sinuses that can cause headaches, a stuffy nose, and other symptoms. Lebeer has previous experience studying gut and vaginal probiotics but realized no one really knew about the nose. Lebeer’s team compared the nose-dwelling bacteria of 100 healthy individuals and 225 people with chronic rhinosinusitis and found that healthy people had up to 10 times as many Lactobacilli in some parts of the nose compared with the rhinosinusitis patients (Cell Rep. 2020, DOI: 10.1016/j.celrep.2020.107674). Lactobacilli are well-known beneficial bacteria, but they generally don’t like high levels of oxygen. The researchers took a closer look and discovered a specific strain they say is well adapted to survive in the nose. The bug has genes to cope with higher oxidative stress levels and bristles with flexible, hairlike tubes called fimbriae, which allow it to stick to cells in the nose. The team also made a nasal spray containing this bacterium and showed they could deliver it to patients. Lebeer says the team is continuing to study how nose Lactobacilli interact with the immune system and how this interaction might reduce inflammation.