Altered gut fungi in systemic lupus erythematosus - A pilot study

The potential pathogenic role of gut microbiota in rheumatic diseases: a human-centred narrative review

A growing amount of evidence suggests that gut microbiota plays an important role in human health, including a possible role in the pathogenesis of rheumatic and musculoskeletal diseases (RMD). We analysed the current evidence about the role of microbiota in rheumatoid arthritis (RA), spondyloarthritis (SpA), systemic lupus erythematosus (SLE) and systemic sclerosis (SSc). In RA, we found a general consensus regarding a reduction of diversity and a specific bacterial signature, with consistent changes according to the different ethnic and geographical areas. The major pathogenetic role in RA is recognised for P. copri, L. salivarius and Collinsella, even if findings become more heterogeneous when considering established disease. In SpA, we found a relative gut abundance of Akkermansia, Coprococcus, Ruminoccocus and a relative reduction in Bacterioides and Firmicutes spp. Human and preclinical data suggest loss of mucosal barrier, increased permeability and Th1- and Th17-mediated inflammation. Additionally, HLA-B27 seems to play a role in shaping the intestinal microbiota and the consequent inflammation. In SLE, the typical gut microbiota signature was characterised by a reduction in the Firmicutes/Bacteroidetes ratio and by enrichment of Rhodococcus, Eggerthella, Klebsiella, Prevotella, Eubacterium and Flavonifractor, even if their real pathogenic impact remains unclear. In SSc, gastrointestinal dysbiosis is well documented with an increase of pro-inflammatory species (Fusobacterium, Prevotella, Ruminococcus, Akkermansia, γ-Proteobacteria, Erwinia, Trabsulsiella, Bifidobacterium, Lactobacillus, Firmicutes and Actinobacteria) and a reduction of species as Faecalibacterium, Clostridium, Bacteroidetes and Rikenella. In conclusion, seems possible to recognise a distinct gut microbiota profile for each RMD, even if significant differences in bacterial species do exist between different studies and there is a high risk of bias due to the cross-sectional nature of such studies. Therefore longitudinal studies are needed, especially on patients with preclinical and early disease, to investigate the real role of gut microbiota in the pathogenesis of RMD.

Alterations of the gut microbiota in the lupus nephritis: a systematic review

BACKGROUND

Emerging evidence suggests that gut microbiota dysbiosis may play a critical role in the development of lupus nephritis (LN). However, the specific characteristics of the gut microbiota in individuals with LN have not been fully clarified.

METHODS

The PubMed, Web of Science, and Embase databases were systematically searched for clinical and animal studies related to the relationship between LN and gut microbiota from inception until October 1, 2023. A semiquantitative analysis was used to assess the changes in gut microbial profiles.

RESULTS

A total of 15 clinical studies were selected for analysis, which included 138 LN patients, 441 systemic lupus erythematosus patients, and 1526 healthy controls (HCs). Five different types of LN mouse models were included in 5 animal studies. The alpha diversity was decreased in LN patients compared to HCs. A significant decrease in the Firmicutes/Bacteroidetes (F/B) ratio is considered a hallmark of pathological conditions. Specifically, alterations in the abundance of the phylum Proteobacteria, genera Streptococcus and Lactobacillus, and species Ruminococcus gnavus and Lactobacillus reuteri may play a critical role in the pathogenesis of LN. Remarkably, the gut taxonomic chain Bacteroidetes-Bacteroides-Bacteroides thetaiotaomicron was enriched in LN patients, which could be a crucial characteristic of LN patients. The increased level of interleukin-6, imbalance of regulatory T cells and T helper 17 cells, and decreased level of the intestinal tight junction proteins zonula occludens-1 and claudin-1 also might be related to the pathogenesis of LN.

CONCLUSIONS

Specific changes in the abundance of gut microbiota such as decreased F/B ratio, and the level of inflammatory indicators, and markers of intestinal barrier dysfunction may play a crucial role in the pathogenesis of LN. These factors could be effective diagnostic and potential therapeutic targets for LN.

Advances in psoriasis and gut microorganisms with co-metabolites

This review summarizes the potential role of gut microbes and their metabolites as novel mediators of psoriasis, including their composition and function in disease pathogenesis, progression, and management. Gut microbiota network analysis, colony construction, and in vivo large-scale interaction experiments showed that different degrees of damage and repair in psoriasis, both in animals and humans, involve cross-border homeostasis of the microbial community. Which gut microbiota interactions are present in psoriasis and how they collaborate with immune cells and influence psoriasis development via the gut-skin axis remain incompletely elucidated. In this article, we review the latest information on the unique patterns of gut microbiota and co-metabolites involved in the pathogenesis of psoriasis and attempt to explore microbial-based therapeutic targets derived from mono-and polymicrobial probiotics, fecal microbiota transplantation, pharmacomicrobiomics, and dietary interventions as diagnostic or therapeutic approaches promising to provide new options and long-term management for psoriasis.

Exploring the Complex Relationship Between Microbiota and Systemic Lupus Erythematosus

PURPOSE OF REVIEW

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by various autoantibodies and multi-organ. Microbiota dysbiosis in the gut, skin, oral, and other surfaces has a significant impact on SLE development. This article summarizes relevant research and provides new microbiome-related strategies for exploring the mechanisms and treating patients with SLE.

RECENT FINDINGS

SLE patients have disruptions in multiple microbiomes, with the gut microbiota (bacteria, viruses, and fungi) and their metabolites being the most thoroughly researched. This dysbiosis can promote SLE progression through mechanisms such as the leaky gut, molecular mimicry, and epigenetic regulation. Notwithstanding study constraints on the relationship between microbiota and SLE, specific interventions targeting the gut microbiota, such as probiotics, dietary management, and fecal microbiota transplantation, have emerged as promising SLE therapeutics.