Researchers have revealed that blooms of the gut bacterium Ruminococcus blautia gnavus may be associated with lupus flares, according to a report published by Azzouz et al in the Annals of the Rheumatic Diseases. Previous studies have demonstrated that R gnavus may be capable of weakening the gut wall barrier, which can increase the risk of bacterial leakages and inflammatory symptoms. In the observational study, researchers conducted taxonomic analyses to examine alterations in the gut microbiota of patients with lupus and individuals without lupus. The researchers detected significant temporal community-wide ecologic microbiota instability with transient intestinal growth spikes for several bacteria among the patients who had lupus. During lupus flares and 50% of lupus nephritis flares, patients had elevated levels of R gnavus. Additionally, the researchers identified 34 genes linked to the growth of R gnavus in patients with inflammatory diseases. Most notably, however, the researchers discovered that the expression of a type of cell membrane–associated lipoglycan with conserved structural features and highly immunogenic repetitive antigenic determinants was present in R gnavus during lupus nephritis flares. In a companion press release from New York University Langone Health, the study authors concluded: “Our findings provide the strongest evidence to date that silent growths of [R] gnavus are tied to active serious renal disease in [patients with] lupus.” They hope their discovery can potentially lead to the development of novel lupus therapeutics.
July 14, 2023