A recent study showed that R. mucilaginosa acts as an anti-inflammatory bacterium in the respiratory tract of patients with chronic lung disease [28]; the study demonstrated that R. mucilaginosa inhibits pathogen-associated pro-inflammatory responses in a mouse model, and the abundance of Rothia species was negatively correlated with pro-inflammatory markers such as interleukin-8, IL-1β, and matrix metalloproteinase in the sputum of bronchiectasis patients. Here, CXCL8 is linked to chronic lung disease.