Objective To compare the intestinal flora metagenomics between osteoarthritis (OA) patients and healthy people in Guangdong province, and to preliminarily analyze the difference and specialty of both groups. Methods Fecal samples were collected from 29 healthy people and 66 patients with knee OA from June 2017 to December 2017 in the Hospital of TCM in Guangdong province. Among them, 17 patients with knee OA were classified into mild OA group and 49 patients were classified into severe OA group, according to K-L classification. Baseline comparison was performed prior to the test. After DNA extraction, Simpson diversity index was used to analyze the community diversity and LEfSe analysis was used to screen key species in the community. GO analysis and Pathway analysis were used to predict the metabolic function of the different flora. Results There was no significant difference in height, age, and weight among the three groups (P>0.05). Simpson diversity index analysis showed that there was no significant difference in intestinal microbial diversity between patients with mild OA and healthy people, while intestinal microbial diversity of patients with severe OA was significantly lower than that of healthy people. LEfSe results showed that 18 species of bacteria, such as Stenotrphomonas and Xanthomonadacease, were significantly abundant in patients with knee OA, while 6 species of bacteria, including Lachnospiraceae and Ruminococcus, were significantly abundant in patients with knee OA. Stenotrphomonas and Xanthomonadacease significantly distinguished patients with mild or heavy knee OA. The GO analysis of the differential species showed that the bacterial flora of Stenotrphomonas and Xanthomonadacease increased significantly, indicating an increasing tendency of the incidence of metabolic diseases, infectious diseases, cardiovascular diseases, and immune diseases. Conclusion There are significant differences in the abundance of intestinal microflora and some microflora between the patients with knee OA and healthy people in Guangdong province. Stenotrphomonas and Xanthomonadacease can be used to obviously predict or diagnosis mild and severe knee OA. |