The Synergistic Effect Of Glycyrrhizic Acid And Lactobacillus Acidophilus On The Gut Microbiota Of Health Mouse

Glycyrrhizic Acid(GA)is a main active element of licorice root,which can be used to inhibit inflammation response and virus infection,and also can protect liver as protective drug.Probiotics are regarded as a group of live bacteria benefical to human health.Lactobacillus acidophilus(L.aci)is one of normally used probiotic,which can enhance host immunity and also inhibit inflammation response and virus infection.In our previous work,we found that oral administration of L.aci can function as a DNA vaccine adjuvant to enhance the specific immunity agasint virus infection.In short,GA and L.aci both not only can be used against inflammation,but also as an immune modulator.However,the synergistic effect of GA and L.aci have not been investigated up to now.In this study,Balb/c mouse was used as experimental models,the synergistic effect of GA and L.aci was firstly investigated by using immune,cell,molecular technology,real time PCR and specifically the next generation sequencing method.The main experiments were including as following:1)the effect of GA on L.aci growth was detected by an in vitro co-culture experiment.2)the synergistic effect of GA and L.aci on the percentage of T regular cell,the levels of cytokines and the structure of gut microbiota of mouse was studied.3)finally,the synergistic antiviral effect of GA and L.aci was measured on CCC-HIE-2 and Caco-2 cell line infected with rotavirus,a human intestinal virus.From the above study,we got the following experimental results:1)GA shown a potential increased effect on L.aci growth in an in vitro co-culture system.However,the final effect and the associated mechanism need to be further investigated in the future.2)By oral administration,utilizaiton of GA in combination with L.aci enhanced the percentage of T regular cells in the blood of mouse,but the level of cytokines such as TNF-a,INF-y,IL-17A and IL-10 in serum and MCP-1,IL-1,iNOs,IL-6 and IL-10 in mouse intestinal tissue were not changed after oral intake of GA,L.aci or the both.In comparison with control group,oral administration of GA significantly increased the divesity of the mouse gut microbiota.L.aci or L.aci plus GA did not change the structure of the gut microbiota.Importantly,oral intake of GA decreased significantly the percentage of the phylum of synergistes compared to administration of L.aci.In addition,we found that utilization of GA in combination with L.aci shown a synergistic anti-virus effect on the model of Caco-2 cell lines infected by rotavirus,but this effect was not observed on CCC-HIE-2 cell line.In conclusion,a promosing synergistic effect of GA and L.aci was improved to enhance host immunity with the increasing percentage of T regular cells,and can inhibit virus infection and inflammation respose.Therefore,our study has provided a theoretic evident and primary experimental data for clinical utilization of GA in combination of L.aci.