Dysbiosis of palatine tonsil microbiota associated with altered immune responses in rheumatoid arthritis. human nasopharyngeal metagenome

The palatine tonsil provides a first defendant line against various microorganisms and has been implicated as a potential site for autoimmunity generation in rheumatoid arthritis (RA), while the underlying mechanism remain largely unknown. Here, we characterized the tonsilar microbiota in RA by utilizing next-generation sequencing. Compared to healthy controls, the tonsilar microbial community in RA patients showed decreased species diversity and shifted taxonomic profiles. Particularly, Lactobacillus salivarius and Capnocytophaga ochracea were overabundant in RA patients and positively associated with disease activity and anti-cyclic citrullinated peptide (anti-CCP) antibody, respectively. Peptostreptococcus anaerobius was under-represented in RA patients and inversely correlated with the numbers of CD8+T lymphocytes. Moreover, RA-associated tonsilar bacteria were partially shared by other microbial community, implying certain covariations of different microbial communities during RA development. Taken together, our work presents the first evidence that the dysbiosis of tonsilar microbiota associates with altered immune responses in RA.