Effects of rhizome of Atractylodes koreana (Nakai) Kitam on intestinal flora and metabolites in rats with rheumatoid arthritis

Atractylodis rhizoma in Chinese Pharmacopoeia are Atractylodes lancea (Thunb.) DC and Atractylodes chinensis (DC.) Koidz. Atractylodes koreana (Nakai) Kitam has not been included in Chinese Pharmacopoeia, however, in the 'dictionary of traditional Chinese medicine', Atractylodes koreana (Nakai) Kitam is often used as Atractylodis rhizoma in the north of China. According to 'Chinese traditional medicine resources', Atractylodes koreana (Nakai) Kitam has the function of drying dampness and strengthening the spleen, dispelling wind and eliminating dampness.The study was to explore the effect and mechanism of Atractylodes koreana (Nakai) Kitam on rheumatoid arthritis(RA) through intestinal flora and its metabolites(short chain fatty acids).36 male SD rats were randomly divided into 6 groups. The Freund's complete adjuvant method was used to reproduce RA model. The contents of inflammatory factors in the plasma of rats were monitored by ELISA method. The pathological changes of synovium were observed. 16SrDNA high-throughput sequence method was used to study the composition and structure of intestinal microflora in each group of rats. Gas Chromatography and Mass Spectrum(GC-MS) method was used to determine the content of short chain fatty acids(SCFAs) in colon of rats of each group.After oral administration of Atractylodes koreana (Nakai) Kitam, the synovial infiltration and vascular proliferation in RA rats were alleviated, the level of TNF - α, IL-1, IL-1 β, IL-2, IL-6, hs-CRP in the plasma of RA rats were declined. RA could cause the disturbance of intestinal flora and SCFAs, Atractylodes koreana (Nakai) Kitam could regulate 8 genera of intestinal flora and improve the disorder of SCFAs.Atractylodes koreana (Nakai) Kitam has a therapeutic effect on RA, the therapeutic mechanism may be related to down-regulating inflammatory factors and improving the imbalance of intestinal flora and SCFAs.