Microorganisms in Pathogenesis and Management of Rheumatoid Arthritis

Interactions between genetic and environmental factors are implicated in the onset of rheumatoid arthritis (RA). There is an increasing appreciation for the association between intestinal microbiome and RA susceptibility. Alterations in intestinal microbiome in untreated patients and patients with established RA on treatment when compared to healthy individuals suggest that intestinal microbiota can be used as a predictor for risk as well as for treatment response. Intestinal microbial composition is strongly influenced by many factors including diet and infections. There is limited information on the use of diet and probiotics to manipulate microbiome and manage RA. Current treatments for RA produce variable response, and responders rarely achieve sustained remission requiring ongoing therapies. Biomarkers that can predict prognosis and therapeutic responses are lacking. Deciphering the use of endogenous commensals with probiotic-like properties and designing probiotics with targeted proteins would help manage RA without the side effects of immunosuppressive treatments. This chapter presents the key concepts of microbial interactions with the host immune system in pathogenicity of rheumatoid arthritis. Also discussed are treatment opportunities using novel treatment strategies such as the use of endogenous commensals and deliberated possible next-generation microbial therapeutics.