Structure and immunomodulatory activity of Lentinus edodes polysaccharides modified by probiotic fermentation

Plant-based fermentations provide an untapped source for novel biotechnological applications.In this study,a probiotic named Lactobacillus fermentum 21828 was introduced to ferment Lentinus edodes.Polysaccharides were extracted from fermented and non-fermented L.edodes and purified via DEAE-52 and Sephadex G-100.The components designated F-LEP-2a and NF-LEP-2a were analyzed by FT-IR,HPGPC,HPAEC,SEM,GC-MS and NMR.The results revealed that probiotic fermentation increased the molecular weight from 1.16×10^(4) Da to 1.87×10^(4) Da and altered the proportions of glucose,galactose and mannose,in which glucose increased from 45.94%to 48.16%.Methylation analysis and NMR spectra indicated that F-LEP-2a and NF-LEP-2a had similar linkage patterns.Furthermore,their immunomodulatory activities were evaluated with immunosuppressive mice.NF-LEP and F-LEP improved immune organ indices,immunoglobulin(Ig G and Ig M)and cytokines concentrations;restored the antioxidation capacity of liver;and maintained the balance of gut microbiota.F-LEP displayed better moderating effects on the spleen index,immunoglobulin,cytokines and the diversity of gut microbiota than NF-LEP(200,400 mg/kg).Our study provides an efficient and environment-friendly way for the structural modification of polysaccharides,which helps to enhance their biological activity and promote their wide application in food,medicine and other fields.

Seabuckthorn juice alleviates allergic symptoms in shrimp-induced food allergy mice

Tropomyosin(TM)in shrimp is one of the predominant causes of food allergy around the world.In the present study,the effect of seabuckthorn juice against TM-induced shrimp allergy was investigated in BALB/c mice.Allergic symptoms,spleen index,intestinal section and diarrhea were measured in shrimp allergy mice.As the results,seabuckthorn juice suppressed the lesions in jejunum tissue,diarrhea and allergic symptoms in shrimp allergy mice.Seabuckthorn juice also reduced serum concentrations of tumor necrosis factor-a(TNF-α)as well as immunoglobulin E(IgE)and stimulated the secretion of interleukin-10(IL-10)in mice with shrimp allergy.Taken together,our findings suggest that increased IL-10 by seabuckthorn juice inhibits Th2 cytokine production to suppress shrimp allergic symptoms.Furthermore,seabuckthorn juice also regulates shrimp allergy by reducing jejunum lesions,inhibiting levels of TNF-αand IgE.