运用“肺病治肠”理论探讨屏障菌群改善肺部炎性反应的研究进展

肺炎是呼吸系统最常见的一类疾病,是全世界传染病、发病率和死亡率的主要原因。细菌性肺炎是最常见的肺炎,影响着所有年龄段人群的肺部疾病,其中儿童、老年和久病卧床者是肺炎的易感人群,临床表现为发热,咳嗽、咯痰等,且预后性较差[1]。

Fermentation Production of Ganoderma lucidum by Bacillus subtilis Ameliorated Ceftriaxone-induced Intestinal Dysbiosis and Improved Intestinal Mucosal Barrier Function in Mice

Objective This study aimed to develop a type of Ganoderma lucidum(G.lucidum)-probiotic fermentation broth that can effectively improve the intestinal mucosal barrier function of mice with ceftriaxone-induced intestinal dysbiosis.Methods By means of absorbance of optical density(OD)value and phenol-concentrated sulfuric acid measurement of polysaccharide content,the probiotic species can grow on the medium of G.lucidum were screened out,and the concentration of the medium of G.lucidum was determined,and the fermentation broth was prepared for subsequent experiments.Thirty-two SPF grade male BALB/c mice were randomly divided into four groups(eight mice in each group),namely control group(CON),intestinal mucosal barrier damage model group(CS),fermentation broth intervention group(FT)and G.lucidum medium intervention group(GL),respectively.The intestinal dysregulation model was induced by intra-gastric administration of 0.2 mL ceftriaxone sodium(twice a day for seven consecutive days).From day 8,the FT group and GL group were gavage with 0.2 mL fermentation broth and G.lucidum medium,respectively.On day 15,all mice were sacrificed.To draw the weight curve and measure the cecal index;pathological examination of colon tissues with HE staining;serum levels of LPS,IL-10,TNF and IL-6 were detected by ELISA.Flow cytometry was used to analyze the changes of CD3+T cells,CD4+T cells,CD8+T cells and macrophages in spleen.16S rRNA sequencing was performed to detect the intestinal microbiota structure of mice.Results Bacillus subtilis can decompose and utilize G.lucidum fruiting body medium,and the suitable concentration of G.lucidum fruiting body medium is 33.2 mg/mL.The effect of Bacillus subtilis-G.lucidum fermentation broth on the damage of intestinal mucosal barrier caused by ceftriaxone sodium was reduced,the body weight of mice recovered and colon swelling improved,colon histopathological injury was alleviated,inflammatory cell infiltration was alleviated,serum IL-10 increased significantly,LPS、TNF-αand IL-6 decreased significantly compared with model group,and the proportion of T cells and intestinal dysbiosis was improved.Conclusions The experimental results suggest that Bacillus subtilis-G.lucidum fermentation broth can effectively improve the intestinal barrier function damage,immune dysfunction and intestinal dysbiosis caused by antibiotic overdose,and has a certain regulatory effect on intestinal mucosal barrier function.

Oral administration of Lactobacillus rhamnosus GG to newborn piglets augments gut barrier function in pre-weaning piglets

To understand the effects of Lactobacillus rhamnosus GG(ATCC 53103)on intestinal barrier function in pre-weaning piglets under normal conditions,twenty-four newborn littermate piglets were randomly divided into two groups.Piglets in the control group were orally administered with 2 mL 0.1 g/mL sterilized skim milk while the treatment group was administered the same volume of sterilized skim milk with the addition of viable L.rhamnosus at the 1st,3rd,and 5th days after birth.The feeding trial was conducted for 25 d.Results showed that piglets in the L.rhamnosus group exhibited increased weaning weight and average daily weight gain,whereas diarrhea incidence was decreased.The bacterial abundance and composition of cecal contents,especially Firmicutes,Bacteroidetes,and Fusobacteria,were altered by probiotic treatment.In addition,L.rhamnosus increased the jejunal permeability and promoted the immunologic barrier through regulating antimicrobial peptides,cytokines,and chemokines via Toll-like receptors.Our findings indicate that oral administration of L.rhamnosus GG to newborn piglets is beneficial for intestinal health of pre-weaning piglets by improving the biological,physical,and immunologic barriers of intestinal mucosa.