<i>Eggerthella lenta</i> augments preclinical autoantibody production and metabolic shift mimicking senescence in arthritis.

Abstract

Although the etiology of rheumatoid arthritis (RA) is unknown, a strong genetic predisposition and the presence of preclinical antibodies before the onset of symptoms is documented. An expansion of <i>Eggerthella lenta</i> is associated with severe disease in RA. Here, using a humanized mouse model of collagen-induced arthritis, we determined the impact of <i>E. lenta</i> abundance on RA severity. Naïve mice gavaged with <i>E. lenta</i> produce preclinical rheumatoid factor and, when induced for arthritis, develop severe disease. The augmented antibody response was much higher in female mice, and among patients with RA, women had higher average load of <i>E. lenta</i>. Expansion of <i>E. lenta</i> increased CXCL5 and CD4 T cells, and both interleukin-17- and interferon-γ-producing B cells. Further, <i>E. lenta</i> gavage caused gut dysbiosis and decline in amino acids and nicotinamide adenine dinucleotide with an increase in microbe-dependent bile acids and succinyl carnitine causing systemic senescent-like inflammation.