Researchers concluded that probiotics could play a role in prevention or treat RA after reviewing current studies on the role of gut microbiota on the development of the disease. However, they encourage further research to determine effective treatment strategies and to promote industry growth in this field.
An important feature of probiotics is their ability to stabilise gut microbiota homeostasis and regulate immune responses, which has led to an increase in their application among patients worldwide, wrote the researchers in Frontiers in Immunology.
Imbalance in the gut microbiota has adverse effects on the host immune system, resulting in susceptibility to various diseases, including RA.
“The manipulability of the gut microbiota makes it possible to locally or systematically manipulate the abundance of specific gut microbiota associated with diseases through interventions, potentially changing the treatment landscape for patients with RA,” said the researchers.
RA is a chronic autoimmune disease that can lead to symptoms such as joint swelling, joint pain, joint deformities, osteoporosis, and even disability. It is commonly mistaken as osteoarthritis (OA), in which joint inflammation is caused by wear and tear that is common among the elderly.
The primary objective in treating RA is to decrease joint inflammation, hinder the progression of lesions and irreversible bone damage, and safeguard the functionality of joints and muscles. The ultimate goal is to attain complete remission of the disease.
Studies on the intestinal microbiota and probiotics have reported their potential in RA prevention and control. Therefore, the researchers wanted to provide direction for the research and application of probiotics in this area.
Researchers conducted a review of recent literature and summarised their findings about the role of gut microbiome in RA.
Compared to healthy individuals, RA patients have a significantly different composition of gut microbiota, which negatively affects their immune defence.
“With continuous research, it has been found that perturbations of gut microbiota have been observed at different stages of RA, such as pre-clinical RA and established RA. In addition, these perturbations of gut microbiota are able to affect the host`s immune response,” said the researchers.
However, when gut microbiota is colonised in the intestines, the immune system can be rebuilt.
Probiotics have been studied in animal and human trials to assess their potential positive effects on the prevention and treatment of RA. Probiotics such as Lactobacillus and Bifidobacterium have been widely investigated.
In a randomised and double-blind clinical trial, 46 RA patients were provided a daily capsule of L. casei 01 for 8 weeks. The serum level of pro-inflammatory cytokines was significantly decreased. The serum regulatory cytokine was increased. The disease activity and inflammatory status of these participants were significantly decreased by L. casei 01 supplementation.
“The results demonstrated that different types of Lactobacillus exerted varying effects on RA. L. reuteri, L. casei, L. rhamnosus, and L. fermentum were found to alleviate RA by inhibiting species-specific pro-inflammatory cytokine and anti-CII antibody signalling pathways and regulating the balance of microflora and metabolites (e.g., short-chain fatty acids) through species-dependent immune regulation in the gut,” wrote the researchers.
The underlying mechanisms through which probiotics work are not yet fully understood. However, it has been observed that probiotics can lead to a reduction in RA disease activity.
“Overall, these mechanisms contribute to the restoration of the balance of intestinal microbiomes and a reduction in systemic inflammation, ultimately leading to a decrease in RA disease activity,” wrote the researchers.
Thus, administering the appropriate probiotic treatment could help prevent or treat RA.
“Probiotics are a potential adjuvant to restore their original intestinal balance and behaviour, and to modulate both innate and adaptive immunity in the host. The use of probiotics prevents or ameliorates the early stage of disease, and may be an effective therapy for chronic inflammatory diseases,” said the researchers.
However, the researchers also highlighted the challenges and difficulties in the application of probiotics in RA.
For example, the cause of RA remains unknown, making the search for effective treatment methods and preventive measures an ongoing area of exploration.
Additionally, while previous studies show that probiotic treatment can alleviate symptoms of RA, the underlying mechanism remains unclear.
The researchers also highlighted that the benefits of probiotics are contingent upon the specific strain, and the reasons for variations between strains remains limited.
Animal and clinical trials have demonstrated the efficacy of probiotics supplementation in alleviating RA symptoms. Therefore, researchers encourage further research to address the challenges of implementing probiotics treatment for RA patients.
“Despite the various challenges that remain in probiotic research, such as determining targets, pathways, and mechanisms, the numerous benefits they offer to the human body continue to drive researchers in their quest for further exploration,” said the researchers.
Source: Frontiers in Immunology
DOI: 10.3389/fimmu.2024.1331486
“Rheumatoid arthritis and the intestinal microbiome: probiotics as a potential therapy”
Authors: Yang Yang, Qing Hong et al.
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