Liubao tea extract ameliorates ovalbumin-induced allergic asthma by regulating gut microbiota in mice

Asthma, a chronic airway inflammatory disease, has a complicated pathogenesis and limited therapeutic treatment. Evidence shows that the intestinal microbiota exhibits crucial functional interaction with asthma syndrome. Liubao tea (LBT), a type of postfermented tea in China, positively modulates gut microbiota. However, the potential benefits of LBT extract (LBTE) for allergic asthma are still not understood. Herein, the anti-inflammatory effects of LBTE and its modulation of the gut microbiota of asthmatic mice induced by ovalbumin were explored. The results demonstrate that LBTE significantly inhibited airway hyper-responsiveness and restrained the proliferation of proinflammatory cytokines and inflammatory cells associated with allergic asthma. Additionally, LBTE suppressed inflammatory infiltration, mucus secretion, and excessive goblet cell production by downregulating the gene expression of inflammatory indicators. Interestingly, fecal microbiota transplantation results further implied that the modulation of LBTE on gut microbiota played an essential role in alleviating airway inflammatory symptoms of allergic asthma.