Microbes, helminths, and rheumatic diseases

Harnessing the Microbiome: A Comprehensive Review on Advancing Therapeutic Strategies for Rheumatic Diseases

Rheumatic diseases are a group of disorders that affect the joints, muscles, and bones. These diseases, such as rheumatoid arthritis, lupus, and psoriatic arthritis, can cause pain, stiffness, and swelling, leading to reduced mobility and disability. Recent studies have identified the microbiome, the diverse community of microorganisms that live in and on the human body, as a potential factor in the development and progression of rheumatic diseases. Harnessing the microbiome offers a promising new avenue for developing therapeutic strategies for these debilitating conditions. There is growing interest in the role of oral and gut microbiomes in the management of rheumatoid arthritis and other autoimmune disease. Microbial metabolites have immunomodulatory properties that could be exploited for rheumatic disorders. A wide range of microorganisms are present in the oral cavity and are found to be vulnerable to the effects of the environment. The physiology and ecology of the microbiota become intimately connected with those of the host, and they critically influence the promotion of health or progression toward disease. This article aims to provide a comprehensive overview of the current state of knowledge on oral and gut microbiome and its potential future role in the management of rheumatic diseases. This article will also discuss newer treatment strategies such as bioinformatic analyses and fecal transplantation.

Th17 cells in primary Sjögren’s syndrome negatively correlate with increased Roseburia and Coprococcus

Background

Dysbiosis of the gut microbiota is closely related to chronic systemic inflammation and autoimmunity, playing an essential role in the pathogenesis of primary Sjögren’s syndrome (pSS). Abnormalities in the proportions of blood T lymphocyte subtype, that is Th17/Treg, were detected in pSS patients. We aimed to determine the associations between gut microbiota and Th17/Treg in pSS.

Method

98 pSS patients and 105 healthy controls (NC) were enrolled between Dec 1, 2018, and Aug 31, 2019. The baseline information and clinical parameters on pSS patients and healthy controls were collected. 16S rRNA sequencing was performed to characterize the gut microbiome and identify gut microbes that are differentially abundant between patients and healthy controls. Lastly, associations between relative abundances of specific bacterial taxa in the gut and clinical outcome parameters were evaluated.

Results

Patients with pSS show decreased gut microbial diversity and richness, decreased abundance of butyrate producing bacteria, such as Roseburia and Coprococcus, and increased abundance of other taxa, such as Eubacterium rectale and Roseburia inulinivorans. These bacteria are enriched with functions related to glycolytic and lipogenic, energy, substance, galactose, pentose metabolism pathways and glucuronate interconversions, decreased with functions related to peptidoglycan biosynthesis, pyrimidine metabolism pathways. An integrative analysis identified pSS-related specific bacterial taxa in the gut, for which the abundance of Eubacterium rectale is negatively correlated with Th17/Treg. Furthermore, the pathways of biosynthesis of secondary metabolites, biosynthesis of amino acids, peptidoglycan biosynthesis and pyrimidine, galactose, pentose, microbial metabolism in diverse environments, glyoxylate and dicarboxylate metabolism are associated with Treg or Th17/Treg.

Conclusions

Primary Sjögren’s syndrome could lead to decreased gut microbial diversity and richness of intestinal flora in patients. The proportions of Th17 and Treg cells induced by microbiota were predictive pSS manifestations and accounted for the pSS severity.

Traditional Tibetan Medicine Twenty-Five Wei’er Tea Pills Ameliorate Rheumatoid Arthritis Based on Chemical Crosstalk Between Gut Microbiota and the Host

Twenty-Five Wei’er Tea Pills (TFP), a traditional Tibetan medicine, has shown to have a promising therapeutic effect in patients with Rheumatoid arthritis (RA), as well as being safe. Nonetheless, there have been limited pharmacological studies that have explored this therapeutic option. As gut microbiota has been proven to have a critical role in the pathogenesis of RA, this study aims to explore and reveal relevant ways by which TFP interacts with the chemical crosstalk between the gut microbiome and its host. 16S rRNA sequencing, combined with un-targeted metabolomics, were conducted on collagen-induced arthritis (CIA) rats. CIA model rats treated with TFP showed significant improvement in weight gain, pathological phenomena in joints, as well as decreased serum levels of TNF-α, IL-6 and increased level of IL-4 and IL-10. Significant dysfunction in the gut microbiome and alteration in serum metabolites were observed in CIA model rats, which were restored by TFP treatment. Coherence analysis indicated that TFP modulated the pathways of histidine metabolism, phenylalanine metabolism, alanine, aspartate, glutamate metabolism, amino sugar and nucleotide sugar metabolism owing to the abundances of Lactobacillus, Bacteroides, Prevotellaceae_UCG-001 and Christensenellaceae_R-7_group in the gut microflora. The corresponding metabolites involved L-histidine, histamine, phenylethylamine, asparagine, L-aspartic acid, D-fructose 1-phosphate, D-Mannose 6-phosphate, D-Glucose 6-phosphate, and Glucose 1-phosphate. In conclusion, this study reveals the ameliorative effects of TFP on RA through the chemical crosstalk that exists between the gut microbiota and its host, and also further enriches our understandings of the pathogenesis of RA.

Analysis of Intestinal Microflora and Metabolites From Mice With DSS-Induced IBD Treated With Schistosoma Soluble Egg Antigen

Objective: This study aimed to analyze the changes in intestinal flora and metabolites in the intestinal contents of mice with inflammatory bowel disease (IBD) to preliminarily clarify the mechanism of action of Schistosoma soluble egg antigen (SEA) on IBD, thus, laying a research foundation for the subsequent treatment of IBD. Methods: A total of 40 Institute of Cancer Research (ICR) mice were divided into four groups: control, SEA 50 μg, dextran sulfate sodium salt (DSS), and SEA 50 μg + DSS. The overall state of the animals was observed continuously during modeling. The colonic length was measured after 10 days of modeling. The degree of colonic inflammation was observed by hematoxylin and eosin staining. 16srRNA and liquid chromatography-mass spectrometry sequencing techniques were used to determine the abundance of bacteria and metabolites in the intestinal contents of mice in the DSS and SEA 50 μg + DSS groups, and the differences were further analyzed. Results: After SEA intervention, the disease activity index score of mice with IBD decreased and the colon shortening was reduced. Microscopically, the lymphocyte aggregation, glandular atrophy, goblet cell disappearance, and colonic inflammation were less in the SEA 50 μg + DSS group than in the DSS group (p < 0.0001). After SEA intervention, the abundance of beneficial bacteria prevotellaceae_UCG-001 was upregulated, while the abundance of the harmful bacteria Helicobacter, Lachnoclostridium, and Enterococcus was downregulated in the intestinal tract of mice with IBD. The intestinal metabolite analysis showed that SEA intervention decreased the intestinal contents of glycerophospholipids (lysophosphatidylcholine, lysophosphatidylethanolamine, phatidylcholine, and phatidylethanolamine) and carboxylic acids (L-alloisoleucine and L-glutamate), whereas increased bile acids and their derivatives (3B,7A,12a-trihydroxy-5A-cholanoic acid and 3A,4B, 12a-trihydroxy-5b-cholanoic acid). Combined microbiota-metabolite analysis revealed a correlation between these differential microbiota and differential metabolites. At the same time, the changes in the contents of metabolites and differential metabolites in the two groups also correlated with the abundance of the gut microbiome. Conclusions: The study showed that SEA reduced DSS-induced inflammation in IBD and improved the symptoms of IBD in mice through the combined regulation of intestinal flora and intestinal metabolism. It suggested a potential possibility for the use of SEA in treating and regulating intestinal flora and metabolism in patients with IBD.

Hypoxia: The "Invisible Pusher" of Gut Microbiota

Oxygen is important to the human body. Cell survival and operations depend on oxygen. When the body becomes hypoxic, it affects the organs, tissues and cells and can cause irreversible damage. Hypoxia can occur under various conditions, including external environmental hypoxia and internal hypoxia. The gut microbiota plays different roles under hypoxic conditions, and its products and metabolites interact with susceptible tissues. This review was conducted to elucidate the complex relationship between hypoxia and the gut microbiota under different conditions. We describe the changes of intestinal microbiota under different hypoxic conditions: external environment and internal environment. For external environment, altitude was the mayor cause induced hypoxia. With the increase of altitude, hypoxia will become more serious, and meanwhile gut microbiota also changed obviously. Body internal environment also became hypoxia because of some diseases (such as cancer, neonatal necrotizing enterocolitis, even COVID-19). In addition to the disease itself, this hypoxia can also lead to changes of gut microbiota. The relationship between hypoxia and the gut microbiota are discussed under these conditions.