[Characteristics of intestinal flora in patients with primary Sjögren syndrome].

OBJECTIVE

To investigate changes in intestinal flora in patients with primary Sj?gren syndrome (pSS) and explore the relationship between pSS disease activity and intestinal flora structure.

METHODS

Fecal samples were collected from 18 female pSS patients, including 9 patients with active disease (group A) and 9 with disease inactivity or low activity (group B), with 10 healthy subjects as the control group. The total bacterial DNA was extracted from the fecal samples for PCR amplification, and Illumina Hiseq 2500 high-throughput sequencing was performed for the v3-v4 region of 16Sr DNA gene to obtain the biological information of the intestinal flora. The intergroup OTU analysis, structural diversity analysis, significant difference analysis and LEFSE analysis were performed with information mining of the literature think tanks.

RESULTS

The dilution curves generated based on the OTUshannon index for analysis of sample complexity showed that the measured data were relatively complete and could reflect the diversity of the microorganisms in the subjects. Analysis of the Alpha diversity index showed that the Shannon index differed significantly between group A and group B, and the Simpson index differed significantly between group A and group B and between group A and the control group ( < 0.05). Sequence analysis the 3 groups all consisted mainly of 4 phylum (, , , showed that the intestinal flora in and ) and 4 genera (, , , and ), all showing no significant differences among the 3 groups ( > 0.05) with the exception of genus, which differed significantly among the 3 groups ( < 0.05). The 16S v3-v4 region in the genus , , , , , , , , , , -, and differed significantly among the 3 groups ( < 0.05). The high-dimensional biometrics and genomic characteristics of the intestinal microorganisms differed significantly among the 3 groups ( < 0.05). According to the size of LDA SCORE (effect size), the core flora in group A included the genera , , -, , -, , , , and , as compared with the genera , , , , , -, , - and in the control group.

CONCLUSIONS

Patients with pSS have significant changes in the diversity of intestinal flora, especially in some specific bacteria in genus and in 16S v3-v4 region of the bacteria. The differences in the core bacteria in the intestinal flora of pSS patients suggest the role of flora structure changes in the pathogenesis of pSS.