Effects Of Bulgaria Inquinans On Murine Immune Functions And Gut Microbiota

Bulgaria inquinans,known as "pig mouth mushroom,wood conch,and wood sea cucumber",belongs to the order Lepidoptera,the rubber gyroscope family,and the rubber gyroscope genus.Bulgaria inquinans mostly grow in the Changbai Mountain Area of Jilin Province and are common on the fallen trees and stumps of broad-leaved trees such as birch and oak in summer and autumn.Bulgaria inquinans is similar to most edible fungi,and riched in nutrients required by the human body.Bulgaria inquinans has antibacterial,antitumor,photosensitive and antipruritic pharmacological activities,Moreover,its polysaccharide extract promotes the proliferation of spleen cells and the phagocytosis of macrophages(M ?).Previous studies on some edible fungi have found that edible fungi are closely related to the action or proliferation of immune cells.It has been confirmed that some edible fungi can enhance NK activity,Ig A production and promote DC cell maturation..In addition,edible fungi also showed a significant regulatory impact on the production of cytokines.These studies suggest that rubber gyroscope may have some immunomodulatory activity.There is still no report on eating intact rubber gyroscope on immune cell function.In addition to the above functions,the extract of Bulgaria inquinans can inhibit harmful bacteria,but this effect is heterogeneous.Different extracts have different effects on different flora,and many edible fungus extracts have adjuvant effects.As for the effect of ingesting the whole rubber gyroscope on the intestinal flora,it is worth studying whether it can be used as an "adjuvant" of the vaccine.Purpose:This study explores the effects of Bulgaria inquinans on immune function and intestinal flora of mice and the adjuvant effect of Bulgaria inquinans on mice immunized with Salmonella.Methods:Divide C57BL/6 female mice into three groups and feed them with feed containing 0%(control group),1%(low-dose group),and 2%(high-dose group)of Bulgaria inquinans.At the same time,the weight change of the mice was recorded.The mice were sacrificed after feeding for 4 weeks.Plasma was collected to detect the levels of alanine aminotransferase,aspartate aminotransferase,;the spleen and mesenteric lymph nodes were collected for restimulation to study the effect of Bulgaria inquinans on peripheral immune cells and local immune cells;feces were collected to examine the impact of Bulgaria inquinans on the intestinal flora.In addition,mice were infected with Salmonella attenuated strain SL1479 to explore whether Bulgaria inquinans could have an adjuvant effect.Results:(1)There was no significant difference in body weight of mice fed with different doses(0%,1%,and 2%)of Bulgaria inquinans.There was no significant difference in the plasma contents of alanine aminotransferase,aspartate aminotransferase,and blood urea nitrogen;(2)The effect of different doses of Bulgaria inquinans on the immune response from splenocytes;(1)Dietary Bulgaria inquinans did not significantly affect the number of T cells and NK cells;2% colloidal gyroscope significantly reduced the number of M ? in splenocytes(P<0.05);(2)Compared with the control group,the ability of splenocytes in 1% and 2% Bulgaria inquinans groups to stimulate T cell proliferation was significantly increased(P<0.05);(3)Compared with the control group,T cells in splenocytes of mice treated with 2% Bulgaria inquinans group significantly increased the secretion of IL-2(P<0.05).(3)The effect of different doses of Bulgaria inquinans on the immune cell function of mesenteric lymph nodes;(1)Dietary intervention with different doses(0%,1%,and 2%)Bulgaria inquinans did not significantly affect the proportion of T cells,M? and NK cells in mesenteric lymph nodes;(2)The proliferation of T cells in mesenteric lymph nodes of mice treated with 1% and 2% Bulgaria inquinans decreased significantly(P < 0.05),and there was no significant difference between the two treatment groups;(3)IL-2,IL-4,IFN-γ,and IL-10 secretion showed a significant downward trend in mesenteric lymph nodes of mice treated with 2% Bulgaria inquinans.(4)2% Bulgaria inquinans compared with the control group,the abundance and diversity of intestinal flora decreased and the dominant flora increased significantly;(5)There is a positive or negative correlation between intestinal flora and cytokines secreted by T cells in mesenteric lymph nodes;(6)Different doses(0%,1% and 2%)of Bulgaria inquinans did not significantly affect the weight and survival rate of mice infected with SL1479.Compared with the control group,the number of colonies in the spleen of mice in the 2% Bulgaria inquinans group increased significantly,but there was no significant difference in the number of colonies in the liver;the proportion of T cells in spleen cells of mice treated with 2% Bulgaria inquinans increased significantly,but the proportion of T cells in mesenteric lymphocytes had no statistical differences.Conclusion:Intake of high-dose(2%)Bulgaria inquinans for 4 weeks can enhance the proliferation of T cells and the production of IL-2 in the peripheral immune organs of mice and reduce the proportion of macrophages while suppressing the T cells in the mesenteric lymph nodes of the local immune organs.At the same time,Bulgaria inquinans can inhibit the proliferation of T cells and the production of cytokines related to T cell function in m LN.After intake of Bulgaria inquinans,the intestinal flora of mice changed.We speculate that the effect of Bulgaria inquinans on the immune function of mice is partly achieved by affecting the intestinal flora.In addition,the intake of Bulgaria inquinans significantly increased the percentage of T cells in the spleen of SL1479 immunized mice and the number of splenic bacteria.We speculated that dietary Bulgaria inquinans intervention might not have the ability to eliminate Salmonella infection,and thus it might not be suitable as a vaccine adjuvant of SL1479.