https://orcid.org/0000-0002-4086-0465
Abstract
Background
Rheumatoid arthritis (RA) is a common autoimmune disease with the main symptoms being joint swelling and pain. In severe cases, joint deformity or even complete loss of function occurs. Technetium methylene diphosphonate (99Tc-MDP) is widely used for RA treatment in China, but there are no studies on the effects of 99Tc-MDP on intestinal flora.
Objective
To explore the effects of 99Tc-MDP treatment on the composition and function of the intestinal flora and to provide new information on the mechanism of 99Tc-MDP in RA treatment.
Methods
Stool samples from RA patients before and after 99Tc-MDP treatment were collected to form two groups (Before and After). Total genomic DNA of the samples was extracted for 16S rRNA gene sequencing. The altered composition of the intestinal flora, the key target bacteria regulated by 99Tc-MDP, and the pathways of action of 99 Tc-MDP were analyzed by bioinformatics.
Results
A total of 64 fresh stool samples were collected from 32 RA patients. Compared to the Before group, the After group showed increased Bacteroidetes abundance and decreased Firmicutes abundance. At the genus level, Prevotella increased whereas Escherichia decreased. Both α and β diversity analyses showed that 99Tc-MDP treatment did not affect gut microbial diversity in RA patients. LEfSe analyses and random forest analyses showed Bacteroidetes, Prevotella, Enterococcus, Escherichia and Ruminococcaceae were the main 99Tc-MDP regulating bacteria. Functional enrichment analysis revealed that the functional differences in gut flora of the two groups centered on Metabolism and Genetic Information Processing.
Conclusion
This study revealed differences in the composition of the gut microbiota in RA patients before and after 99Tc-MDP treatment. The therapeutic effect of 99Tc MDP is mainly achieved through Bacteroidetes, Prevotella, and Enterococcus. Regulating metabolism and genetic information processing of gut flora may be the mechanism of 99Tc-MDP in treating RA.
Data Sharing Statement
The raw sequencing data are deposited into the NCBI BioProject (http://www.ncbi.nlm.nih.gov/bioproject/871753) under accession number: PRJNA871753. The study protocol and the datasets generated during analysis during the current study will be available from the corresponding author on reasonable request.
Ethical Statement
The study was approved by the Ethics Committee of the Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine (GK2019004), and all participants signed an informed consent form. All study procedures involving human participants were in accordance with the 1964 Declaration of Helsinki and its subsequent revisions.
Acknowledgments
This research was supported by the Laboratory Department of the Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine. The author is very grateful to the serum analysts in the laboratory. The authors would like to thank all the nurses who assisted in collecting stool samples.
Disclosure
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.