LB975 The role of gut flora metabolite butyrate in inhibiting mast cell activation via deacetylase in chronic spontaneous urticaria

Chronic spontaneous urticaria (CSU) is an immune-related skin disease characterized by abnormal activation of mast cells (MCs). With the advanced research on gut flora in diseases, it suggested that dysbiosis may contribute to pathogenesis CSU, but mechanisms involved are unknown. Butyrate, a metabolite flora, variety cellular physiological processes as histone deacetylase inhibitor (HDACi) and exerts beneficial effects intestinal tract other organs. It not clear whether can be CSU affecting cell activity through its butyrate. In present study, we detected patients healthy individuals 16s rRNA massive sequencing. The differential analysis microbiota composition showed relative abundance Firmicutes was significant decreased patients. A bacteria Firmicutes, such Clostridium Streptococcus, major producers And decrease these results lower levels butyrate body. vitro experiments, used DNP-Bull serum albumin (BSA) induce anaphylactic reactions degranulation We found pretreatment MCs significantly inhibited Fc epsilon RΙ (FcεRΙ) -mediated activation, including release cytokines. Our provide evidence leads reduced patients, inhibits IgE-mediated activation. hypothesize acting HDACi affect expression signaling pathway proteins, which will confirmed further experiments. This study help reveal mechanism involvement basis for search new treatment strategies future.