Fecal microbiota in patients with ankylosing spondylitis: Correlation with dietary factors and disease activity

Background: We investigated the characterization of the gut microbiome in Chinese patients with ankylosing spondylitis (AS) and healthy controls (HCs) and to explore the association of bacteria communities with dietary factors and disease activity. Methods: 16S ribosomal RNA gene sequencing was performed on fecal DNA isolated from stool samples in consecutive cross-sectional cohorts. Alpha and beta diversities were assessed using QIIME, and comparisons were performed using one-way ANOVA, Student's t-test, and SKN multiple range comparisons to examine differences between groups and a correlation network analysis was performed. Results: We investigated 207 samples from 103 AS patients and 104 HCs. Alpha diversity was not significant difference in AS compared with HCs. For the community structure, Bacteroidetes was the most represented class. Megamonas, Dorea, and Blautia were significantly greater in AS than in HCs, whereas the abundance of Lachnospira, Ruminococcus, and Clostridium_XlVb was significantly lower in AS than in HCs. In addition, Specific gut microbiome was significantly correlated with disease activity and dietary factors. Conclusions: Our results suggest that the human gut microbiome of AS patients was clearly different from that of HCs and bacteria communities are associated with dietary factors and disease activity.