Subsequent experiments in a mouse mannequin of rheumatoid arthritis (RA) demonstrated that the bacterium attenuated joint irritation by regulating butyrate and immune cells and re-establishing immune tolerance.
“This discovery offers a brand new clear goal for probiotic immunotherapy of RA, doubtlessly enhancing remedy effectiveness and enhancing affected person prognosis,” wrote researchers from The Second Hospital of Shanxi Medical College and different establishments in China and the US.
The gut-joint axis
The gut-joint axis is an rising mechanism that scientists are learning within the context of ailments that have an effect on the joints, reminiscent of RA, osteoarthritis and spondyloarthritis.
The intestine microbiome performs a key position in regulating the immune system, and research have linked dysbiosis to irritation within the joints. Nevertheless, “whether or not a purposeful gut-joint axis exists has but to be established,” famous a 2025 paper published in Science.
Animal studies counsel that the event of RA is related to intestine irritation, intestinal permeability and elevated ranges of zonulin, the protein that regulates tight junctions within the intestine barrier. Dysbiosis and altered intestinal permeability might induce persistent activation of immune cells that recirculate to joints, resulting in irritation.
Subsequently, manipulating the intestinal microbiome might present an efficient technique to alleviate joint problems and autoimmune ailments reminiscent of RA.
The researchers on the present research famous that microbes reminiscent of Clostridium butyricum and Bacteroides fragilis have beforehand been recognized as being concerned in RA and have been utilized in medical remedies. Nonetheless, there could also be many different micro organism that might be helpful.
E. rectale is a bacterium that produces the short-chain fatty acid butyrate, which is important for preserving intestinal well being. The bacterium has obtained consideration resulting from its hyperlinks with autoimmune ailments, together with psoriasis, inflammatory bowel illness, a number of sclerosis and psoriatic arthritis.
Research particulars
The researchers used RNA sequencing to evaluate how intestinal flora from fecal samples differed between 38 contributors newly identified with RA recruited from Shanxi Medical College’s Second Hospital and 22 wholesome controls (HC).
They discovered vital variations between the 2 teams. They recognized Eubacterium rectale as a key bacterium exhibiting a protecting impact on RA. Then, they used E. rectale to deal with arthritis mannequin mice and evaluated their joint irritation and immune profile earlier than and after the intervention utilizing metabolomics to evaluate modifications in serum and fecal metabolites.
The outcomes confirmed enhancements in joint irritation, bone well being and immune cells. The intervention reversed the modifications in metabolites reminiscent of butyric acid that have been seen with induced arthritis.
“When the variety of E. rectale decreases, it results in enhance in proinflammatory cytokines (reminiscent of IL-6 and TNF-α),” the researchers wrote.
“As well as, the shortage of butyrate weakens the intestinal barrier’s integrity, which can make it straightforward for the antigenic substances within the gut to set off systemic autoimmune reactions”, they added, recommending additional research to validate their findings.
Supply: Frontier in Immunology. Quantity 16 – 2025. doi: 10.3389/fimmu.2025.1607804. “ From intestine to joint: the protecting impression of Eubacterium rectale on rheumatoid arthritis”. Authors: X. Liu et al.
