Amelioration of dextran sodium sulphate-induced colitis in mice by treatment with Lactobacillus rhamnosus and Lactobacillus reuteri:intraspecific and interspecific patterns

Lactobacillus rhamnosus(Rh)and Lactobacillus reuteri(Re)are well-known probiotic species in inflammatory bowel disease(IBD)research.The variations between these species’efficacy against colitis,and their model of action in this regard,are intriguing and enable treatment to be individually tailored to patients.In this study,four strains each of Rh and Re were isolated from fecal samples and their draft genomes were sequenced.The anti-colitis activities of both strains involved various aspects of intestinal immune,physical,chemical,and biological barrier function.Strikingly,the tested strains exhibited considerable interspecies and intraspecies specificity in colitis amelioration.Rh strains significantly outperformed Re strains in terms of short-chain fatty acid synthesis.Nevertheless,Re strains were more effective than Rh strains in inhibiting production of inflammatory factors;promoting production of intestinal mucus,antimicrobial peptides,and tight junction proteins;and supporting the stem cell compartment.This accounts for the anti-colitis outcomes of Re strains being superior to those of Rh strains.In addition,the effective Rh and Re strains were found to express high concentrations of specific carbohydrate metabolism-and prophage-related genes,respectively.Taken together,the results of this study could assist researchers in developing effective therapies for IBD.

Effect of fructooligosaccharides on the colonization of Lactobacillus rhamnosus AS 1.2466^(T) in the gut of mice

Lactobacillus rhamnosus and fructooligosaccharides(FOS)have been widely studied so far.However,the effects of L.rhamnosus on the intestinal microecological environment at the species level and the effect of different proportions of FOS on L.rhamnosus colonization in different parts of mice intestine are still unclear.The study results indicated that the specific bands of enterobacterial repetitive intergenic consensus polymerase chain reaction(ERIC-PCR)in the L.rhamnosus(LR)group significantly increased at 7 days.Although the number of bands was similar to the natural recovery(NR)group,the brightness of few bands significantly enhanced in the later stage of recovery.Besides,Southern-blot maps showed strong signals,indicating that the ERIC-PCR fingerprint could accurately reflect the changes in the mouse gut microbiota diversity.Further,the high-throughput results confirmed that the Lactobacillus and Akkermansia had different changes at different periods,but all of them showed an upward trend,while the Klebsiella were inhibited,thereby maintaining the intestinal microecology balance.Moreover,FOS exerted a positive effect on L.rhamnosus colonization in the gut.

Lactobacillus rhamnosus GR-1 attenuates foodborne Bacillus cereus-induced NLRP3 inflammasome activity in bovine mammary epithelial cells by protecting intercellular tight junctions

Background:Bacillus cereus is an important pathogen that causes human food poisoning,specifically diarrhea and vomiting.B.cereus can also induce mastitis in dairy cows and has a strong survival ability in milk,as it cannot be inactivated by high-temperature short-time pasteurization.Therefore,B.cereus can enter the market through pasteurized milk and other dairy products,imposing enormous hidden dangers on food safety and human health.Results:In this study,B.cereus 2101(BC)was isolated from milk samples of cows with mastitis.BC grew rapidly with strong hemolysis,making it difficult to prevent mastitis and ensure food security.MAC-T cells were treated with BC and/or Lactobacillus rhamnosus GR-1(LGR-1).Pretreatment with LGR-1 protected the integrity of tight junctions and the expression of zonula occludens-1(ZO-1)and occludin destroyed by BC.Furthermore,LGR-1 pretreatment reduced the expression of NOD-like receptor family member pyrin domain-containing protein 3(NLRP3),caspase recruitment and activation domain(ASC),Caspase-1 p20,gasdermin D(GSDMD)p30,inflammatory factors(interleukin(IL)-1βand IL-18),and cell death induced by BC.Moreover,LGR-1 pretreatment reduced NLRP3 inflammasome activity and increased expressions of ZO-1 and occludin induced by lipopolysaccharides(LPS)+ATP stimulation.MAC-T cells were transfected with NLRP3 si RNA or MCC950 and/or treated with BC and/or LGR-1.NLRP3-si RNA transfection and MCC950 attenuated BC-induced NLRP3 inflammasome activity.Expression of inflammatory cytokines and cell death suggested that the inflammatory pathway might play an important role in the induction of the NLRP3 inflammasome by BC and the protection of LGR-1.Conclusions:These results suggest that LGR-1 might be a probiotic alternative to antibiotics and could be administered to prevent mastitis in dairy cows,thus ensuring food security.

Exopolysaccharides of Lactobacillus rhamnosus GG ameliorate Salmonella typhimurium-induced intestinal inflammation via the TLR4/NF-κB/MAPK pathway

Background Salmonella typhimurium(S.T),as an important foodborne bacterial pathogen,can cause diarrhea and gastroenteritis in humans and animals.Numerous studies have confirmed that exopolysaccharides(EPSs)have various biological functions,but the mechanism through which EPSs improve the immunity of animals against the invasion of pathogenic bacteria is unclear.Here,we explored the protective effect of EPSs of Lactobacillus rhamnosus GG(LGG)on the S.T-infected intestine.Methods Mice received adequate food and drinking water for one week before the start of the experiment.After 7 d of prefeeding,2×108 CFU/mL S.T solution and an equivalent volume of saline(control group)were given orally for 1 d.On the fourth day,the mice were treated with 0.5 mg/mL EPSs,1.0 mg/mL EPSs,2.0 mg/mL EPSs,or 2.0 mg/mL penicillin for 7 d.Finally,the body and relative organ weight,histological staining,and the levels of antioxidant enzyme activity and inflammatory cytokines were determined.Results The S.T-infected mice exhibited symptoms of decreased appetite,somnolence,diarrhea and flagging spirit.Treatment with EPSs and penicillin improved the weight loss of the mice,and the high dose of EPSs showed the best therapeutic effect.EPSs significantly ameliorated S.T-induced ileal injury in mice.High-dose EPSs were more effective than penicillin for alleviating ileal oxidative damage induced by S.T.The mRNA levels of inflammatory cytokines in the ileum of mice showed that the regulatory effects of EPSs on inflammatory cytokines were better than those of penicillin.EPSs could inhibit the expression and activation of key proteins of the TLR4/NF-κB/MAPK pathway and thereby suppress the level of S.T-induced ileal inflammation.Conclusions EPSs attenuate S.T-induced immune responses by inhibiting the expression of key proteins in the TLR4/NF-κB/MAPK signaling pathway.Moreover,EPSs could promote bacterial aggregation into clusters,which may be a potential strategy for reducing the bacterial invasion of intestinal epithelial cells.

氮源与维生素对鼠李糖乳杆菌(Lactobacillus rhamnosus)高效生产L-乳酸影响的研究

在L-乳酸发酵生产中，用廉价的黄豆粉补充微量维生素液，替代培养基中昂贵的酵母粉，L-乳酸的产物浓度和得率与使用酵母粉相比相差不大。氮源经优化后，使用3．5％～4．5％的黄豆粉并添加最优剂量的8种维生素混合液，摇瓶实验，120g／L葡萄糖转化得到104g／L的L-乳酸，得率为86．7％；5L发酵罐实验，3.5％的黄豆粉补充维生素混合液，初始葡萄糖浓度150g／L，L-乳酸浓度为128g／L，得率达到85．3％，基本达到了以酵母粉做氮源和生长因子的发酵指标。

高糖和氮源对鼠李糖乳杆菌(Lactobacillus rhamnosus)L-乳酸发酵的影响

鼠李糖乳杆菌经实验室耐高糖高酸选育,能够在高糖浓度下高效高产L-乳酸。以酵母粉为氮源和生长因子,葡萄糖初始浓度分别为120 g/L和146 g/L,摇瓶培养120h,L-乳酸产量分别为104g/L和117.5g/L,L-乳酸得率分别为86.7%和80.5%。高葡萄糖浓度对菌的生长和乳酸发酵有一定的抑制。增加接种量,在高糖浓度发酵条件下,可以缩短发酵时间,但对增加乳酸产量效果不明显。乳酸浓度对鼠李糖乳杆菌生长和产酸有显著的影响。初始乳酸浓度到达70g/L以上时,鼠李糖乳杆菌基本不生长和产酸,葡萄糖消耗也被抑制。酵母粉是鼠李糖乳杆菌的优良氮源,使用其它被测试的氮源菌体生长和产酸都有一定程度的下降。用廉价的黄豆粉并补充微量维生素液,替代培养基中的酵母粉,可以使产酸浓度和碳源得率得以基本维持。

鼠李糖乳酸杆菌Lactobacillus rhamnosus GG胞外多糖合成与提取优化研究

试验旨在对鼠李糖乳杆菌(Lactobacillus rhamnosus GG,LGG)胞外多糖的提取工艺和合成条件进行优化。采用单因素试验分别研究三氯乙酸浓度、乙醇添加量和乙醇沉淀时间对胞外多糖提取量的影响,利用单因素结合正交试验对碳源、葡萄糖浓度、培养基初始pH值、接种量、培养温度、培养时间等影响胞外多糖合成的条件进行优化。结果表明,胞外多糖合成的最佳条件为:培养基中添加20 g/l的葡萄糖,调节其pH值为6.5,在30℃培养20 h,在此条件下,胞外多糖的产量为230.2 mg/l。胞外多糖最佳提取条件为:用11%的三氯乙酸除蛋白,4倍体积95%的乙醇沉淀24 h,胞外多糖提取效果较佳。

Ehealth:Low FODMAP diet vs Lactobacillus rhamnosus GG in irritable bowel syndrome

AIM: To investigate the effects of a low fermentable, oligosaccharides, disaccharides, monosaccharides and polyols diet (LFD) and the probiotic Lactobacillus rhamnosus GG (LGG) in irritable bowel syndrome (IBS).

Lactobacillus rhamnosus GG ameliorates DON-induced intestinal damage depending on the enrichment of beneficial bacteria in weaned piglets

Background: Deoxynivalenol(DON) is one of the most common environmental pollutants that induces intestinal inflammation and microbiota dysbiosis. Lactobacillus rhamnosus GG(LGG) is a probiotic that not only has anti-inflammatory effects, but also shows protective effect on the intestinal barrier. However, it is still unknown whether LGG exerts beneficial effects against DON-induced intestinal damage in piglets. In this work, a total of 36 weaned piglets were randomized to one of four treatment groups for 21 d. The treatment groups were CON(basal diet);LGG(basal diet supplemented with 1.77 × 10^(11)CFU/kg LGG);DON(DON-contaminated diet) and LGG + DON(DON-contaminated diet supplemented with 1.77 × 10^(11)CFU/kg LGG).Result: Supplementation of LGG can enhance growth performance of piglets exposed to DON by improving intestinal barrier function. LGG has a mitigating effect on intestinal inflammation induced by DON exposure, largely through repression of the TLR4/NF-κB signaling pathway. Furthermore, supplementation of LGG increased the relative abundances of beneficial bacteria(e.g., Collinsella, Lactobacillus, Ruminococcus_torques_group and Anaerofustis), and decreased the relative abundances of harmful bacteria(e.g., Parabacteroides and Ruminiclostridium_6), and also promoted the production of SCFAs.Conclusions: LGG ameliorates DON-induced intestinal damage, which may provide theoretical support for the application of LGG to alleviate the adverse effects induced by DON exposure.

Effects of the viability of Lactobacillus rhamnosus GG on rotavirus infection in neonatal rats

AIM:To study the effects of live and dead Lactobacillus rhamnosus GG(GG) on rotavirus infection in a neonatal rat model.METHODS:At the age of 2 d,suckling Lewis rat pups were supplemented with either live or dead GG and the treatment was continued daily throughout the experi-ment.At the age of 5 and 6 d the pups received oral rotavirus(RV) SA-11 strain.The pups were sacrificed at the age of 7 or 8 d by decapitation.The gastrointestinal tract was removed and macroscopic observations were done.The consistency of feces in the colon was classified using a four-tier system.RV was detected from the plasma,small intestine,colon and feces by real-time quantitative polymerase chain reaction(PCR).RESULTS:In this neonatal rat model,RV induced a mild-to-moderate diarrhea in all except one pup of the RV-inoculated rats.RV moderately reduced body weight development from day 6 onwards.On day 7,after 2 d of RV infection,live and dead GG groups gained significantly more weight than the RV group without probiotics [36%(P = 0.001) and 28%(P = 0.031),respectively].In addition,when compared with the RV control group,both live and dead GG reduced the weight ratio of colon/animal body weight to the same level as in the healthy control group,with reductions of 22%(P = 0.002) and 28%(P < 0.001),respectively.Diarrhea increased moderately in both GG groups.However,the diarrhea incidence and severity in the GG groups were not statistically significantly different as compared with the RV control group.Moreover,observed diarrhea did not provoke weight loss or death.The RV control group had the largest amount of RV PCR-positive samples among the RV-infected groups,and the live GG group had the smallest amount.Rats receiving live GG had significantly less RV in the colon(P = 0.027) when compared with the RV control group.Live GG was also more effective over dead GG in reducing the quantity of RV from plasma(P = 0.047).CONCLUSION:Both live and dead GG have beneficial effects in RV infection.GG may increase RV clearance from the body and reduce colon swelling.

Lactic Acid Fermentation from Coffee Ground Waste Hydrolysate by Lactobacillus rhamnosus

Lactic acid is an important organic acid that is widely used in the food,pharmaceutical,and cosmetic industries.Lactic acid was produced from coffee ground waste which contains fermentable sugars and is increasingly generated from our daily dietary life.Among 114 strains of Lactobacillus species,Lactobacillus rhamnosus ATCC 10863 was selected for the production of lactic acid from coffee ground waste.Through alkali pretreatment and saccharification,cellulose and hemicellulose in coffee ground waste were converted into fermentable sugars.Pretreatment experiments were conducted at various alkali solution,concentrations,and times.Alkali pretreatment with 35 g/L of KOH at 121oC for 60 min,the highest concentration of fermentable sugars was produced.The optimum concentration of Viscozyme L was 2%when saccharification was proceeded at 55oC for 7 days.The productivity of lactic acid fermentation was the highest(0.59 g/L/h)at 100 g of coffee ground waste(1x concentration),whereas the lactic acid concentration was the highest at 600 g of coffee ground waste(6x concentration).As the concentration of coffee ground increased,the lactic acid concentration was also increased,however,the amount was not proportional to the coffee ground waste used.In this study,it was found that coffee ground waste could be used as a culture medium for Lactobacillus rhamnosus ATCC 10863 through pretreatment and saccharification for the production of lactic acid.

Fermentation Characteristics of Silage of Sugar Cane Treated with Calcium Oxide,Lactobacillus buchneri and Their Associations

We evaluated the fermentation products, the gaseous and effluent losses of sugarcane silages without calcium oxide (CaO) or with CaO addition, at the levels of zero, 0.8%, 1.6% and 2.4%, in association with the microbial additive Lactobacillus buchneri inoculated at the levels of zero, 50.000, 100.000 e 150.000 ufc/g of sugarcane, wet bases. The variety RB855536, harvested after 12 months of first growth was used. The experiment design was the completely randomized design, in a 4 × 4 factorial arrangement. They were evaluated in the silages, the contents of volatile fatty acids, lactic acid, ethanol, and the pH, as well as the gaseous and effluent losses. In the analysis of the data, the SAS system was utilized. It was observed on interaction effect of the chemical and microbial additive over the contents of lactic acid, acetic acid, propionic acid, butyric acid, ethanol and over the gaseous and effluents losses. However, there was no interaction effect regarding to pH. When it was observed on interaction effect of additives, the effects of the levels of one additive were evaluated by regression analysis in each level of each other, and vice-versa. The level 1.6% of CaO associated to the level 50,000 ufc/g of natural matter of Lactobacillus buchneri provided adequate levels of lactic acid (superior to 4.5%), and of acetic acid (around 1%), moderate content of propionic acid (0.55%), low content of butyric acid (0.05%) and controlled the production of ethanol and the gaseous and effluent losses. The pH of the silages were influenced by CaO addition, but were not affected consistently by microbial inoculation.

Effect of probiotic Lactobacillus rhamnosus GG intervention on global serum lipidomic profiles in healthy adults

AIM: To investigate the effect of three weeks’ intervention with a probiotic Lactobacillus rhamnosus GG (LGG) bacteria on global serum lipidomic profiles and evaluate whether the changes in inflammatory variables (CRP, TNF-α and IL-6) are reflected in the global lipidomic profiles of healthy adults. METHODS: We performed UPLC/MS-based global lipidomic platform analysis of serum samples (n = 26) in a substudy of a randomised, double-blind, placebo- controlled 3-wk clinical intervention trial investigating the immunomodulatory effects of probiotics in healthy adults. RESULTS: A total of 407 lipids were identified, corresponding to 13 different lipid classes. Serum samples showed decreases in the levels of lysophosphatidylcholines (LysoGPCho), sphingomyelins (SM) and several glycerophosphatidylcholines (GPCho), while triacylglycerols (TAG) were mainly increased in the probiotic LGG group during the intervention. Among the inflammatory variables, IL-6 was moderatelyassociated by changes in global lipidomic profiles, with the top-ranked lipid associated with IL-6 being the proinflammatory LysoGPCho (20:4). There was a weak association between the lipidomic profiles and the two other inflammatory markers, TNF-α and CRP. CONCLUSION: This was the first study to investigate the effects of probiotic intervention on global lipidomic profiles in humans. There are indications that probiotic LGG intervention may lead to changes in serum global lipid profiles, as reflected in decreased GPCho, LysoGPCho and SM as well as mainly increased TAG.

Soothing Efficacy and Tolerability of a Skin Care Product Containing Live Lactobacillus rhamnosus Bacteria and Berry Seed Oils on Atopic Dermatitis Lesions

Background: Atopic dermatitis (AD) is a chronic pruritic inflammatory skin disease characterized by a reduced microbiome diversity which favours the skin colonization with pathogenic bacteria, mainly with Staphylococcus aureus. A novel approach to the management of several skin diseases, including AD, involves the use of specific beneficial probiotic bacteria aimed at restoring the skin microbiome balance and decreasing the skin colonization with pathogens. Objective: This study assessed the soothing efficacy and tolerability of a new probiotic-based skin care product combining two live Lactobacillus rhamnosus strains and berry seed oils on eczematous lesions in subjects with atopic skin. Patients and Methods: Twenty-five adults with atopic skin and presenting at least one inflammatory lesion applied the product on the defined lesion for 28 days, once to twice daily. Severity of eczema signs (EASI score) and intensity of pruritus (VAS) were assessed, and digital images were captured following treatment. Cutaneous tolerability and subject satisfaction were also investigated. Results: A statistically significant decrease in mean EASI score was observed after 28 days (-27%, p = 0.011). A visible improvement in skin aspect was observed in 67% of the subjects on week 4. On average, the intensity of pruritus decreased by 57% as compared to baseline (p = 0.011). This effect was observed in 86% of the subjects. No relevant adverse reactions were observed following treatment with the skin care product and the majority of the subjects appreciated the product for its general characteristics, properties, and efficacy. Conclusion: The results suggest that this skin care product containing two live Lactobacillus rhamnosus strains and berry seed oils could be used for the treatment of eczematous lesions in subjects with atopic skin.

Interaction between Dairy Yeasts and Lactobacillus rhamnosus GG in Milk

The presence of Geotrichum candidum in fresh cheese is considered to be a contaminant and may lead to the product spoilage. The oxidative yeast Candida maltosa firstly isolated from the spoiled fruit yoghurt surface in Slovakia belongs to the yeast contaminants of fermented dairy products. The effect of the cultivation temperature and the presence of Lactobacillus rhamnosus GG on the growth of dairy spoilage yeasts in ultrapasteurized milk was studied. Addition of Lb. rhamnosus GG in milk caused partial inhibition of the yeast growth dynamics in milk. The water activity transformation of Gibson model after the temperature modification （Tw） was applied to model growth dynamics of G. candidum in pure and mixed culture, respectively： In μ_Gc=-5.0376＋2.7281 Tw-0.4217Tw^2, lnμ_CC_LGG=-6.0033＋3.2996Tw-0.5553Tw^2. The effect of different Lb. rhamnosus GG addition and the incubation temperature on the C. maltosa growth dynamics was analyzed by linear regression methodology and described by using following equations： lnGr1=-5.3674＋0.2341T＋0.2599N0-0.0032T^2-0.0492N0^2-0.0068TN0 and lnGr11=-9.5457-0.249T＋2.3823N0 ＋0.0099T^2-0.2324N0^2＋0.0098TN0 Based on the principles of predictive microbiology, the mutual microbial interactions and potential application of the lactobacillus strains in food protection are discussed.

Lactobacillus buchneri IMAU80233高密度发酵工艺优化

以工业化生产为出发点,对具有潜在益生特性Lactobacillus buchneri IMAU80233高密度培养工艺进行优化。采用Bioscreen C读值系统,在MRS培养基的基础上,对适合L.buchneri IMAU80233生长增殖培养基成分进行快速筛选优化。优化后最适培养基为果糖80 g/L,大豆蛋白胨23.90 g/L,酵母粉11.90 g/L,柠檬酸1.59 g/L,柠檬酸钠20.06 g/L,MnSO4·5H2O 0.09 g/L,MgSO4·7H2O 0.60 g/L,精氨酸0.50 g/L,吐温-801.00 g/L。采用5 L×3联发酵罐进行小试,确定初始pH值为6.5,37℃恒定pH 5.9培养20 h,发酵初期通入氮气,优化后发酵液活菌数达3.81×10^9 CFU/mL。

Efficacy of Lactobacillus rhamnosus GG in treatment of acute pediatric diarrhea: A systematic review with meta-analysis

BACKGROUND Diarrhea is a major infectious cause of childhood morbidity and mortality worldwide.In clinical trials,Lactobacillus rhamnosus GG ATCC 53013(LGG)has been used to treat diarrhea.However,recent randomized controlled trials(RCTs)found no evidence of a beneficial effect of LGG treatment.AIM To evaluate the efficacy of LGG in treating acute diarrhea in children.METHODS The EMBASE,MEDLINE,PubMed,Web of Science databases,and the Cochrane Central Register of Controlled Trials were searched up to April 2019 for metaanalyses and RCTs.The Cochrane Review Manager was used to analyze the relevant data.RESULTS Nineteen RCTs met the inclusion criteria and showed that compared with the control group,LGG administration notably reduced the diarrhea duration[mean difference(MD)-24.02 h,95%confidence interval(CI)(-36.58,-11.45)].More effective results were detected at a high dose≥1010 CFU per day[MD-22.56 h,95%CI(-36.41,-8.72)]vs a lower dose.A similar reduction was found in Asian and European patients[MD-24.42 h,95%CI(-47.01,-1.82);MD-32.02 h,95%CI(-49.26,-14.79),respectively].A reduced duration of diarrhea was confirmed in LGG participants with diarrhea for less than 3 d at enrollment[MD-15.83 h,95%CI(-20.68,-10.98)].High-dose LGG effectively reduced the duration of rotavirus-induced diarrhea[MD-31.05 h,95%CI(-50.31,-11.80)]and the stool number per day[MD-1.08,95%CI(-1.87,-0.28)].CONCLUSION High-dose LGG therapy reduces the duration of diarrhea and the stool number per day.Intervention at the early stage is recommended.Future trials are expected to verify the effectiveness of LGG treatment.

Effect of Lactobacillus rhamnosus GG supernatant on serotonin transporter expression in rats with post-infectious irritable bowel syndrome

AIM To evaluate the effect of Lactobacillus rhamnosus GG supernatant(LGG-s) on the expression of serotonin transporter(SERT) in rats with post-infectious irritable bowel syndrome(PI-IBS).METHODS Campylobacter jejuni 81-176(1010 CFU/m L) was used to induce intestinal infection to develop a PI-IBS model. After evaluation of the post-infectious phase by biochemical tests, Dn A agarose gel electrophoresis, abdominal withdrawal reflex(AWR) test, and the intestinal motility test, four PI-IBS groups received different concentrations of LGG-s for 4 wk. The treatments were maintained for 1.0, 2.0, 3.0 or 4.0 wk during the experiment, and the colons and brains were removed for later use each week. SERT m Rn A and protein levels were detected by real-time PCR and Western blot, respectively.RESULTS The levels of SERT m Rn A and protein in intestinal tissue were higher in rats treated with LGG-s than in control rats and PI-IBS rats gavaged with PBS during the whole study. Undiluted LGG-s up-regulated SERT m Rn A level by 2.67 times compared with the control group by week 2, and SERT m Rn A expression kept increasing later. Double-diluted LGG-s was similar to undiluted-LGG-s, resulting in high levels of SERT m Rn A. Triple-diluted LGG-s up-regulated SERT m Rn A expression level by 6.9-times compared with the control group, but SERT m Rn A expression decreased rapidly at the end of the second week. At the first week, SERT protein levels were basically comparable in rats treated with undiluted LGG-s, double-diluted LGG-s, and triplediluted LGG-s, which were higher than those in the control group and PBS-treated PI-IBS group. SERT protein levels in the intestine were also comparable in rats treated with undiluted LGG-s, double-diluted LGG-s, and triple-diluted LGG-s by the second and third weeks. SERT m Rn A and protein levels in the brain had no statistical difference in the groups during the experiment.CONCLUSION LGG-s can up-regulate SERT m Rn A and protein levels in intestinal tissue but has no influence in brain tissue in rats with PI-IBS.

Lactobacillus rhamnosus ATCC53103和Escherichia coli ATCC8739对结直肠癌细胞CT26增殖及凋亡的影响

目的:探究Lactobacillus rhamnosus ATCC53103、Escherichia coli ATCC8739对CT26细胞增殖、迁移及凋亡的影响。方法:以CT26细胞为研究对象,1∶100加入L.rhamnosus ATCC53103与E.coli ATCC8739,定植培养一定时间后,分别采用台盼蓝染色法、划痕法、流式细胞仪检测细胞的增殖、迁移以及凋亡,采用RT-PCR与Western blot方法检测凋亡基因caspase-3、caspase-9、bcl-2、bax、fas的转录水平与表达情况。结果:L.rhamnosus ATCC53103和E.coli ATCC8739对CT26细胞的增殖与迁移有抑制作用,并促进CT26细胞的凋亡。两者相比较,L.rhamnosus ATCC53103的作用更为缓和。经RT-PCR和Western blot检测发现,L.rhamnosus ATCC53103使得CT26细胞凋亡基因caspase-3、caspase-9的表达上调,而E.coli使得CT26细胞凋亡基因caspase-3表达下调。结论:L.rhamnosus ATCC53103和E.coli ATCC8739能抑制CT26细胞的增殖、迁移,促进细胞的凋亡,L.rhamnosus ATCC53103可能通过线粒体相关途径使细胞发生凋亡;而E.coli ATCC8739则不是通过caspase-3执行细胞的凋亡作用。

Optimizational production of phenyllactic acid by a Lactobacillus buchneri strain via uniform design with overlay sampling methodology

A Lactobacillus buchneri GBS3 strain isolated from the traditional Chinese pickles was used for the production of 3-phenyllactic acid(PLA), an important compound with antimicrobial activities against a wide species of grampositive and gram-negative bacteria and some fungi. The growth performance of this strain in the de Man, Rogosa and Sharpe(MRS) medium, the production of metabolites of valuable organic acids, and the biosynthesis of PLA using this strain as the whole-cell biocatalyst and phenylpyruvic acid(PPA) as the precursor, were investigated experimentally. The uniform design method with overlay sampling was developed for the optimization of the biotransformation conditions. The results showed that although it produced naturally lactic acid with the maximum concentration of 1.84 g·L^(-1) and PLA with the concentration of 0.015 g·L^(-1) after 66 to 72 h cultivation in MRS broth by fermentation, the present strain displayed an effective utilization ability by transforming PPA to PLA. By the uniform design method with overlay sampling for the design and optimization of transformation conditions, a maximum yield of 10.93 g·L^(-1) PLA with the mole conversion ratio of 83.07% from PPA to PLA was achieved under the optimized condition, i.e., 20 g·L^(-1) glucose, 270 g·L^(-1) cells, 13 g·L^(-1) PPA, pH 8.0 and the reaction time of 15 h, indicating that Lactobacillus buchneri GBS3 was an interesting strain for the biosynthesis of PLA via the microbial transformation. The prediction of PLA yield under different conditions was achieved successfully based on the limited information of only a small number of experiments by the uniform design with overlay sampling. Therefore, the present methodology is effective and helpful for the optimization of the biosynthesis processes of PLA.