The intervention effects of Lactobacillus casei LC2W on Escherichia coli O157:H7-induced mouse colitis

This study investigated the intervention effects of Lactobacillus casei LC2W in murine(SPF C57BL/c)challenge infection models induced by Escherichia coli O157:H7.Mice were fed streptomycin with water for 3 days prior to intragastric gavage by E.coli O157:H7(Control)or L.casei LC2W together with E.coli O157:H7(Intervention)to explore the role of L.casei LC2W by biochemical indicators,histological evaluation,expression of colonic pro-inflammatory and intestinal barrier factors related to enteritis.Results showed that the administration of L.casei LC2W was able to alleviate the symptoms of colitis induced by E.coli O157:H7,exhibiting lower weight loss as well as more intact colon tissue.Furthermore,L.casei LC2W could down-regulate the expression of pro-inflammatory cytokines(TNF-α,IL-6,and IL-1β)and protect the intestinal barrier function by improving the level of MUC2,ZO-1 and E-cadherin 1 compared to the control group.These results demonstrate that L.casei LC2W can reduce the severity of E.coli O157:H7 infection,and suggest L.casei LC2W may maintain the immune balance and intestinal barrier to reduce colitis.In addition,we found the effect of intervention is similar to that of prevention,which is better than that of treatment.

Expression of Human Chorionic Gonadotropin β(hCGβ) in Lactobacillus Casei

Objective To construct a recombinant lactobacillus (Lb.) strain excreting the human chorionic gonadotropin beta-subunit (hCGβ) Methods The hCGβ cDNA was ligated to the signal peptide sequence of S-layer protein from Lb. brevis and then cloned into down-stream of lactose-inducible promoter of an integrative plasmid, pIlac. After electroporation into Lb. casei CECT5276, PCR using the genomic DNA of the recombinant lactobacillus as template was performed to confirm whether the hCGβ gene had been integrated into the genome. Radioimmunoassay (RIA) was used to determine the level of hCGβ in the supernatant and the cell lysate. Results The hCGβ was integrated into the genome of Lb. casei CECT5276. The highest concentration of hCGβ in the culture supernatant amounted to 440 mIU/mL 21 h after lactose induction. About 2/3 of the abstract Objective proteins were excreted into the supernatant. Conclusion We have obtained stable and efficient hCGβ excretion in Lb. casei, which was inducible by lactose.

No Additional Cholesterol-Lowering Effect Observed in the Combined Treatment of Red Yeast Rice and Lactobacillus Casei in Hyperlipidemic Patients：A Double-Blind Randomized Controlled Clinical Trial

Objective：To observe the effect of combining red yeast rice and Lactobacillus casei（L.casei）in lowering cholesterol in patients with primary hyperlipidemia,the later has also been shown to remove cholesterol in in vitro studies.Methods：A double-blind clinical trial was conducted to evaluate the cholesterol-lowering effect of the combination of red yeast rice and L.casei.Sixty patients with primary hyperlipidemia were recruited and randomized equal y to either the treatment group（red yeast rice＋L.casei）or the control group（red yeast rice＋placebo）.One red yeast rice capsule and two L.casei capsules were taken twice a day.The treatment lasted for 8 weeks,with an extended follow-up period of 4 weeks.The primary endpoint was a difference of serum low-density lipoprotein cholesterol（LDL-C）level at week 8.Results：At week 8,the LDL-C serum level in both groups was lower than that at baseline,with a decrease of 33.85±26.66 mg/dL in the treatment group and 38.11±30.90 mg/dL in the control group;however,there was no statistical difference between the two groups（P〉0.05）.The total cholesterol was also lower than the baseline in both groups,yet without a statistical difference between the two groups.The only statistical y significant difference between the two groups was the average diastolic pressure at week 12,which dropped by 2.67 mm Hg in the treatment group and increased by 4.43 mm Hg in the placebo group（P〈0.05）.The antihypertensive activity may be associated with L.casei.Red yeast rice can significantly reduce LDL-C,total cholesterol and triglyceride.Conclusion：The combination of red yeast rice and L.casei did not have an additional effect on lipid profiles.

Fermented soy whey induced changes on intestinal microbiota and metabolic influence in mice

Soy whey(SW)is generated as process waste while preparing soy protein isolates(SPI),and causing severe environmental pollution.Therefore,its value-added utilization is of prime importance for transforming and upgrading traditional industry.This study aims to utilize SW as a substrate for the growth of probiotics and produce a SW based synbiotics.By a series of trials,the effect of the dietary supplementation with this fermented SW(FSW)was analyzed on ICR mice's body weight,metabolites,and intestinal microbiota in 4 weeks.The results showed that,when SW was concentrated 15 times,the count of viable Lactobacillus casei reached 3.4×10^(9) CFU/mL by liquid fermentation method,which was the highest viable cell count among all test strains.In this FSW,the protein,amino acid,total dietary fibre,soluble dietary fibre,and oligosaccharide were 2.10%,1.63%,0.52%,0.51% and 0.79%,respectively.Compared to two control group,the total yields of the short chain fatty acids(SCFAs)were significantly improved(75%-125% at average),while the SCFAs structure was also significantly changed(especially acetic acid and butyrate)in the faeces of mice fed FSW.Meanwhile,FSW dietary addition was associated with the diversity and richness of the intestinal microbiota.Obviously,with mice's body weight loss,Firmicutes/Bacteroides ratio reduced accordingly(<1.21),and the abundance of Akkermansia muciniphila was significantly increased(the maximum amount was about 0.013%).In summary,our results indicated that the dietary supplementation of FSW affected mice's intestinal microbiota and metabolism and improved their health profile.