Comparison of Intestinal Microbes in Noninfectious Anterior Scleritis Patients With and Without Rheumatoid Arthritis

Abstract

We compared intestinal microbes in anterior noninfectious scleritis patients with and without rheumatoid arthritis. Active noninfectious anterior scleritis patients without other immune diseases (G group, 16 patients) or with active rheumatoid arthritis (GY group, seven patients) were included in this study. Eight age- and sex-matched healthy subjects served as controls (N group). DNA was extracted from fecal samples. The V3-V4 16S rDNA region was amplified and sequenced by high-throughput 16S rDNA analysis, and microbial contents were determined. A significant decrease in species richness in the GY group was revealed by α- and β-diversity analyses (p = 0.02 and p = 0.004, respectively). At the genus level, 14 enriched and 10 decreased microbes in the G group and 13 enriched and 18 decreased microbes in the GY group were identified. Among them, four microbes were enriched in both the G and GY groups, including Turicibacter, Romboutsia, Atopobium, and Coprobacillus. Although two microbes (Lachnospiraceae_ND3007_group and Eggerthella) exhibited similar tendencies in the G and GY groups, changes in these microbes were more significant in the GY group (p < 0.05). Interaction analysis showed that Intestinibacter, Romboutsia, and Turicibacter, which were enriched in both the G and GY groups, correlated positively with each other. In addition, nine microbes were decreased in the GY group, which demonstrates a potential protective role for these microbes in the pathogenesis of scleritis via interactions with each other.

Keywords: Atopobium; Coprobacillus; Romboutsia; Turicibacter; intestinal microbes; noninfectious anterior scleritis; rheumatoid arthritis; scleritis.

Figure 1

(A) α-Diversity using the Chao1, observed OTUs, PD_whole_tree, and Shannon measures for patients with active noninfectious anterior scleritis, patients with active noninfectious anterior scleritis combined with active rheumatoid arthritis, and healthy controls. (B) β-Diversity was assessed by analysis of molecular variance (ANOVA) in patients with active noninfectious anterior scleritis, patients with active noninfectious anterior scleritis combined with active rheumatoid arthritis, and healthy controls. (C) Rarefaction curves of the gut microbes from 16 patients with active noninfectious anterior scleritis, seven patients with active noninfectious anterior scleritis combined with active rheumatoid arthritis, and 11 healthy controls.

Figure 2

(A) Relative abundance of microbes in 16 patients with active noninfectious anterior scleritis (G) and 11 healthy controls (N); (B) Linear discrimination analysis (LDA) effect size (LEfSe) analysis results comparing active noninfectious anterior scleritis patients (G) and 11 healthy controls (N); (C) Relative abundance of microbes in seven patients with active noninfectious anterior scleritis combined with active rheumatoid arthritis (GY) and 11 healthy controls (N); (D) LDA LEfSe analysis results comparing patients with active noninfectious anterior scleritis combined with active rheumatoid arthritis (GY) and 11 healthy controls (N). The content of microbes (A,C) was increased by 10⁶-fold; the logarithm was taken, and the base number was 10. LDA scores (B,D) (log10) > 2 are listed.

Figure 3

Relative abundance of microbes from 16 patients with active noninfectious anterior scleritis (G), seven patients with active noninfectious anterior scleritis combined with active rheumatoid arthritis (GY), and 11 healthy controls (N). The content of microbes is presented based on the row scale.

Figure 4

Interaction network diagram of microbes related to Group G (A) and Group GY (B). Red represents a positive correlation. The thicker the line is, the stronger the correlation is. The group with a larger sector area has a higher content of this microbe.

Figure 5

Changes in the gut microbiome in the G and GY groups and patients with rheumatoid arthritis. Underlined intestinal microbes exhibited increased abundances, and microbes without underlining exhibited decreased abundances.