Table 1.
Up-to-date Human analysis of gut microbiota in rheumatoid arthritis (RA).
| Author/Year/Ref. | Cases | Controls | Method | Results |
|---|---|---|---|---|
| Scher et al., 2013 [48] | New onset RA patients (n = 44) | Chronic RA patients (n = 26); Healthy controls (n = 28); Psoriatic arthritis (n = 16) | 16S sequencing; Shotgun sequencing on a subset of 44 samples; Antibiotic treated mice model. | Specific P. copri increase in NORA. P. copri mice colonization increased sensitivity to chemically induced colitis. |
| Zhang et al., 2015 [52] | RA patients: Naïve Treatment (n = 94); DMARD Treatment (n = 21) | Healthy controls (n = 97) | Shotgun sequencing (fecal, dental, and salivary samples). | Concordance between gut and oral microbiomes. Haemophilus spp. depleted in RA, at all three sites, and negatively correlated with serum auto-antibodies. Lactobacillus salivarius over-represented in RA. No significant difference in P. copri. |
| Maeda et al., 2016 [47] | RA patients (n = 17) | Healthy controls (n = 14) | 16S sequencing; SKG germ-free mice model | 1/3 of RA microbiota dominated by Prevotella species (80% P. copri). “Prevotella-dominated” RA microbiota increased arthritis severity in mice. |
| Chen et al., 2016 [53] | Treated RA patients (n = 40) | Asymptomatic FDRs (n = 15); Healthy controls (n = 17) | 16S sequencing; Human epithelial cell line and humanized mouse model of CIA | Decreased gut microbial diversity in RA. Eggerthella and Collinsella genus associated with RA; decrease of Faecalibacterium. No association between RA and Prevotella copri. Collinsella aerofaciens increased incidence and severity of mice arthritis, as well as intestinal permeability. |
| Alpizar-Rodriguez et al., 2019 [8] | Seropositive or symptomatic FDRs (n = 83) | Asymptomatic FDRs (n = 50) | 16S sequencing. | Enrichment Prevotella copri in the ’pre-RA’ group. Decreased Oxalobacteraceae. No difference in alpha or beta diversity. |
| Jeong et al., 2019 [49] | Pre-clinical and untreated NORA (n = 29) | Healthy controls (n = 25) | 16S sequencing. | Prevotella genus slightly enriched in RA and pre-RA subjects. Collinsella decreased in RA. |
| Kishikawa et al., 2020 [50] | RA (71% untreated)(n = 85) | Healthy controls (n = 42) | Shotgun sequencing. | Enrichment of Prevotella species in the RA. No difference in overall diversity. |
| Mena-Vazquez et al., 2020 [54] | Stable RA patients (n = 40) | Healthy controls (n = 40) | 16S sequencing. | No difference in diversity. Enterococcus, Sedimentibacter, and Collinsella significantly more frequent in RA. Decrease in Sarcina and Porphyromonas. Collinsella aerofaciens increased in RA patients. |
| Y. Tong et al., 2020 (abstract) [51] | High-risk pre-Ra ACPA positive (n = 42); RA patients (n = 31) | Healthy controls (n = 38) | 16S sequencing. CIA mice model. | Bacteroidaceae abundance decreases in pre-RA and RA. Mice CIA more severe after FMT with stool from pre-RA. Associates with reduced gut barrier function and intestinal epithelial damage. |
RA—Rheumatoid Arthritis. NORA—New-Onset Rheumatoid arthritis. DMARD—Disease Modifying Anti-Rheumatic Drugs. FDRs: First-Degree Relatives of RA patients. CIA—Collagen-Induced Arthritis. FMT—Fecal Microbiota Transplantation.