Impact of Gut Microbiota and Probiotics on Rheumatoid Arthritis: A Potential Treatment Challenge.

Over the past few decades, there has been a surge in global study on the relationship between gut microbiota and human health. Numerous human illnesses have been linked to dysbiosis. Gram-positive firmicutes and Gram-negative bacteroidetes are the two leading bacterial phyla that make up 90% of the gut microbiome. Many symbionts in the gut environment establish intricate relationships with host defense to stop both local and non-native dangerous bacteria from colonizing and invading. Dysbiosis alters the paracellular route and damages the epithelium, enabling them to penetrate the epithelium and come into contact with the immune cells. Impaired intestinal barrier function, immune regulation mediated by metabolites derived from the gut microbiota, posttranslational modification of host proteins such as increased citrullination, regulation of the gut microbiota's effect on immune cells, intestinal epithelial cell autophagy, interaction between the microbiome and human leukocyte antigen alleles, and interaction with microRNAs are some of the mechanisms involved in rheumatoid arthritis (RA). The gut microbiota, Prevotella copri, and Collinsella spp. were shown to be higher in the early/preclinical phases of RA, while Bacteroidetes, Bifidobacteria, and Eubacterium rectale were found to be lower. Probiotic-based early dietary intervention may reduce inflammation and slow the rate of joint deterioration, and such intervention can also aid in the restoration of gut microbiota equilibrium. This review article describes the gut microbial dysbiosis and role of probiotics in RA.