Effect of Se-enriched Lactobacillus on Antibody of NDV of Broilers

This study was conducted to investigate the effect of Se-enriched lactobacillus on antibody of Newcastle Disease Virus(NDV)of broilers.One thousand day-old AA broiler chickens were selected from a chicken farm of Jinghai County,and the chickens were divided randomly into two groups,which respectively had five repeat groups with 100 chickens each,one named basal diet group,and the other named Se-enriched lactobacillus group.Corn soybean meal diet was selected for basal diet group,while 2%se-enriched lactobacillus was added into corn soybean meal diet for the other group.The method of feeding was free diet,drinking,and routine immunization program was adopted.This test period was 42 d.Two chickens were selected randomly in each repeat for slaughtering and collecting serums on the 14th,28th and 42nd d.Assessments on the effect of Se-enriched lactobacillus in antibody titer of NDV of broilers were made by hemagglutination-inhibition test.The results indicated that antibody titer of NDV was increased significantly by Se-enriched lactobacillus.

蜂蜜中艾皮斯乳杆菌A9(Lactobacillus apis A9)的分离鉴定及其对铅的吸附作用

为了探究蜂蜜中乳酸菌的益生特性,从蜂蜜中分离纯化出一株革兰氏阳性菌,结合菌落和菌体特征、生理生化反应以及16S rDNA测序技术分析,鉴定该菌为艾皮斯乳杆菌(Lactobacillus apis)。安全性实验表明,该菌株A9不溶血,不水解明胶,不还原硝酸,无氨基酸脱羧能力,对青霉素等9种抗生素敏感。益生实验结果显示该菌有高自聚集率(93.37%)和较高的疏水率(48.71%),pH值3的环境下培养3 h存活率为43.67%,在1 wt.%胆酸钠溶液、6 wt.%NaCl溶液、25 wt.%葡萄糖溶液中分别培养24 h后,存活率分别为96.48%、68.27%、88.57%。表明该菌具有很强的耐酸耐胆盐和耐高渗能力。该菌吸附重金属铅的结果显示,对Pb2+的吸附率高达55.53%。铅占菌体表面的元素百分比为5.90%。红外结果表明,菌体表面的羟基、氨基与铅离子发生了相互作用,造成菌体蛋白的α螺旋和β转角增加,β折叠减少。结果表明,从蜂蜜中筛选出的Lactobacillus apis A9具有良好的安全性、益生功能及良好的重金属铅吸附能力,为蜂蜜中乳酸杆菌的开发利用,提供了新的思路。

小麦蛋白水解物对嗜酸乳杆菌(Lactobacillus acidophilus)生长的影响研究

该研究对比了小麦蛋白水解物与不同蛋白胨对嗜酸乳杆菌生长的影响,重点从分子质量分布、氨基酸组成等方面解析了小麦蛋白水解物对嗜酸乳杆菌(Lactobacillus acidophilus)形态、活菌数、冻干存活率的影响。结果表明,小麦蛋白水解物是一种适用于嗜酸乳杆菌培养的有机氮源,同等培养条件下活菌数和冻干存活率高于其他蛋白胨,小麦蛋白水解物中分子质量为2000~5000 Da的组分是促进嗜酸乳杆菌生长的关键营养,含谷氨酰胺、脯氨酸组成的多肽可能是促进嗜酸乳杆菌缩短菌体,活菌数和冻干存活率提高的关键因素。该研究结果可为小麦蛋白水解物在嗜酸乳杆菌生产及其他发酵领域的应用提供一定的基础数据支撑。

羊源Lactobacillus plantarum对腹泻羔羊空肠菌群及肠道黏膜屏障的调控作用

旨在研究Lactobacillus plantarum对腹泻羔羊血清抗氧化能力和空肠菌群及空肠黏膜屏障损伤的调控作用。本试验选用24只刚断奶的羔羊,采用完全随机试验设计随机分为4组,分别为对照组(C组)、腹泻组(D组)、腹泻+抗生素处理组(DA组)、腹泻+植物乳杆菌处理组(DL组),每组6个重复,在正式试验第1天开始对D组、DA组和DL组羔羊分别灌服20 mL ETEC K99菌液,持续8 d。在第9天早上,DA组羔羊注射氟苯尼考,DL组羔羊灌服植物乳杆菌菌液,持续4 d。试验第1、9、13天空腹采集羔羊血液用于检测羔羊血清抗氧化指标以及二胺氧化酶(DAO)和D-乳酸(D-LA)浓度;屠宰后采集羔羊空肠内容物以测定菌群组成,采集空肠组织用于检测肠道黏膜屏障相关蛋白和黏膜蛋白,阿利新蓝(AB)染色研究酸性黏液的变化。结果表明:1)大肠杆菌处理8 d后,D、DA和DL三组羔羊粪便均不成形,且三组羔羊血清中DAO和D-LA浓度显著高于C组(P<0.05),说明腹泻模型构建成功;2)在第9天,与C组相比,D、DA和DL组羔羊血清中T-AOC、SOD显著降低(P<0.05),MDA含量显著升高(P<0.05);与第9天相比,DA和DL组羔羊在第13天时其抗氧化能力显著增加(P<0.05),DAO、D-LA浓度和MDA显著降低(P<0.05);3)与C组相比,D组羔羊空肠组织Occludin、Claudin1和MUC2蛋白表达量显著下降(P<0.05);与D组相比,DA组羔羊空肠组织Occludin蛋白表达量显著提高(P<0.05),但Claudin1蛋白和MUC2蛋白的表达量有所降低(P>0.05);DL组羔羊空肠组织Occludin蛋白、Claudin1蛋白以及MUC2蛋白表达量显著高于DA组;4)与C组相比,D和DA组羔羊空肠内容物中菌群Chao值和Shannon值均显著降低(P<0.05),DL羔羊空肠内容物中菌群Chao值和Shannon值有所增加(P>0.05)。C、D和DL组羔羊空肠中Firmicutes丰度均显著高于DA组(P<0.05)。C、D和DA组Actinobacteriota丰度都显著高于DL组(P<0.05)。D组羔羊空肠中Proteobacteria丰度略高于C和DL组(P>0.05),DA组羔羊空肠中Proteobacteria丰度显著高于C、D和DL组(P<0.05)。经相关性分析发现,与MUC2表达相关的微生物较多,Proteobacteria与空肠MUC2的表达显著负相关(P<0.05),Firmicutes和Verrucomicrobiota与空肠MUC2的表达显著正相关(P<0.05),NK4A214_group与MUC2表达量显著正相关(P<0.05),Escherichia-Shigella与MUC2的表达显著负相关(P<0.05)。综上表明,ETEC K99诱发羔羊腹泻,腹泻羔羊血清抗氧化能力和空肠内容物微生物多样性降低、空肠黏膜屏障蛋白表达量降低。相比于抗生素治疗,灌服Lactobacillus plantarum增加了空肠内容物菌群多样性,促进空肠酸性黏液及黏膜组织屏障蛋白的表达。总体而言,Lactobacillus plantarum对羔羊腹泻改善效果更佳。

Antiseptic Efficacy of A Soap Made from Biosurfactants Isolated from Bacillus and Lactobacillus against Pathogenic Bacteria

The aim of our study was to use a biosurfactant produced by Bacillus and Lactobacillus isolates as an antiseptic in the formulation of local soap. A total of 60 isolates were characterized by microbiological techniques (30 Bacillus and 30 Lactobacillus) and the ability to produce biosurfactants was demonstrated by a hydrocarbon emulsification index (E24). The emulsification indexes (E24) varied from 9% to 100% for Bacillus and from 33% to 100% for Lactobacillus as well. The antagonistic assay showed that biosurfactants were able to inhibit the formation of biofilms and growth of pathogens such as Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, Salmonella typhirium, Shigella boydii and Proteus mirabilis. The biosurfactant consortium (BioC) from Bacillus consortium and from Lactobacillus was able to inhibit biofilm formation and the pathogens growth. The BioC was stable to alkaline pH and the temperatures stability of Biosurfactant was ranging from 50°C to 90°C. The soap was made by the cold saponification process using one biosurfactant consortium formulated. This soap has a pH of 10 and showed good cleaning power and good foam stability. Similarly, the soap showed good antiseptic power and disinfection power against all pathogens tested. Handwashing is critical to preventing disease transmission. The persistence of pathogens in waste water was evaluated. The BioS produced showed good disinfection power against all pathogens tested. The valor of reduction on the hands and in the waste water was significantly more than compared to the control soaps used. This soap could be used in the prevention, fighting, and treatment of bacterial and viral infections.

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.

Impact of Dietary Lactobacillus plantarum Postbiotics on the Performance of Layer Hens under Heat Stress Conditions

This experiment was conducted to determine the performance of heat-stressed layers fed a diet containing the probiotic Lactobacillus plantarum RS5 or its products of fermentation (postbiotics). Twenty-week-old Isa White layers, were subdivided into six treatments of 32 individually caged birds. Half of the birds were reared under regular temperature conditions, while the other half was subjected to cyclic daily heat stress. Layers were offered one of three diets: 1) Control;2) Control + Lactobacillus plantarum RS5 probiotic;3) Control + Lactobacillus plantarum RS5 postbiotics. Birds were tested for performance and visceral organ development for 5 months. Heat stress negatively affected the birds’ feed intake, egg weight, shell weight percentage, Haugh unit, shell thickness, yolk color, body weight and spleen weight percentage. Postbiotics significantly increased egg production (p < 0.05) in comparison to the control and the probiotic fed group (94.8% vs 92.6% vs 93.1%, respectively). Birds under probiotic or postbiotic diet showed a significantly higher (p < 0.05) feed intake and egg weight, although the probiotic had a more pronounced and gradual effect. Specific gravity, yolk weight percentage and shell thickness didn’t show differences among dietary groups. The Haugh Unit was significantly higher (p < 0.05) in probiotic group which also showed a significantly lower yolk color index (p < 0.05). The different feed treatments did not impact the bird’s viscera weight percentage, except for the ileum that was significantly lower (p < 0.05) under postbiotic supplementation. Both probiotics and postbiotics could be used as a potential growth promoters and might alleviate heat stress impact in poultry industry.

没食子酸对植物乳杆菌Lactobacillus plantarum的抑制和促进生长

该文以微生物生长曲线、多酚浓度变化和培养液pH值变化为指标,研究了没食子酸(GallicAcid,GA)和表没食子儿茶素没食子酸酯(Epigallocatechin Gallate,EGCG)对植物乳杆菌CICC 6253生长的影响。结果表明GA和EGCG对植物乳杆菌生长的影响具有浓度依赖性,可表现出抑制和促进的双向调节作用,且二者的作用存在构效差异性。在GA和EGCG分别在5 mg/mL和7 mg/mL以上时,两者都抑制了植物乳杆菌的生长,而当GA和EGCG分别低于4 mg/mL和6 mg/mL时二者都促进了细胞的增殖,且随质量浓度增加其促进作用增大。GA可作为碳源被植物乳杆菌迅速利用,而EGCG(4 mg/mL)因其良好的细胞亲和性表现出显著的促进作用,高效地促进了植物乳杆菌细胞的增殖,菌落数在28h内由7.42lgCFU/mL增加到12.54lgCFU/mL,与空白对照组相比增加了2个数量级以上。本研究表明,GA和EGCG均表现出对植物乳杆菌的双向调节作用,其中EGCG表现出更佳的益生特性。本文研究结果可为GA和EGCG及类似食源性多酚在益生菌生长调节和相关食品研发中提供参考。

Demonstration of safety characteristics and effects on gut microbiota of Lactobacillus gasseri HMV18

Human normal flora is a source of probiotics.The safety characteristics of a specific isolate determine its application in foods or drugs.The food-borne-pathogen antagonist strain Lactobacillus gasseri HMV18 is one of the isolates from normal human flora.In this work,we assessed the in vitro pH tolerance,bile tolerance,biogenic amine production,mucin utilization,and safety of in vivo administration to mice to evaluate general health,organ-body weight index,organ histopathological change,whether L.gasseri HMV18 can colonize in the gut or modulate the gut microbiota after oral administration.The results suggest that L.gasseri HMV18 can tolerate pH 3 for 2 h,3%bile for 3 h,biogenic amine negative,mucin usage negative,does not encode verified toxins,and cause no visible change in mice's organs.L.gasseri HMV18 might not colonize in mice's gut,but can significantly affect the structure of gut microbiota.A bibliographical survey suggested that there were as few as 8 opportunistic infection cases from 1984 to 2022 and that the possibility for L.gasseri to cause infection is relatively low.Therefore,this work provides a basis for the foods or drugs application of L.gasseri HMV18 and gives a map of experiments for the safety assessment of probiotics.

Ameliorative effects of Lactobacillus fermentum isolated from individuals following vegan, omnivorous and high-meat diets on ulcerative colitis in mice

Lactobacillus spp.can be beneficial for the prevention or treatment of ulcerative colitis(UC).In this study,153 participants who followed vegan,omnivorous,or high-meat diet were recruited.Compositional analysis of the Lactobacillus community in feces revealed that Lactobacillus fermentum strains were significantly affected by diet.Administration of mixed L.fermentum strains from vegans significantly improved inflammation compared to that from omnivores and high-meat consumers,as evidenced by a significant reduction in colonic tissue damage,improvement in inflammatory cytokines,enhanced expression of ZO-1,occludin,and claudin-3,and a significant increase in short chain fatty acids concentration.The effect of a single strain of L.fermentum was similar to that of a mixed strains of L.fermentum group.Genomic analysis suggested that L.fermentum strains from the guts of vegans possessed a higher prevalence of genes involved in carbohydrate catabolism than those from the guts of omnivores and high-meat eaters.In particular,the ME2 gene is involved in the biosynthesis of acetate,a compound considered to possess anti-inflammatory properties.In conclusion,this study indicates strain-specific differences in the ability of L.fermentum strains to alleviate UC in mice,influenced by habitual diets。

The influence of Lactobacillus plantarum fermentation in selenium-enriched Brassica napus L.:changes in the nutritional constituents,bioactivities and bioaccessibility

Selenium(Se)-enriched Brassica napus L.is a valuable organic Se supplement.In this study,the fermentation broth enriched with organic Se(FFS)was prepared using Lactobacillus plantarum to ferment the substrate of Se-enriched Brassica napus L.Significant increases were observed after fermentation in total sugars,reducing sugars,soluble proteins,total phenolic content(TPC),and total flavonoid content(TFC).The organic Se was retained at a concentration of 54.75 mg/g in the freeze-dried sample.Principal component analysis and cluster analysis showed good separation between the FFS and unfermented(FS)groups.Fragrant 2-ethyloxetane had the highest content among all volatiles,while sinapine had the highest content among all phenolic compounds.The fermentation process showed remarkable improvement in the abundance and concentration of volatile compounds and phenolic contents,making FFS exhibit strong antioxidant activity and inhibitory capacity againstα-glucosidase activity.The bioaccessibility of phenolic compounds was significantly greater in FFS compared to FS.ADMET analysis revealed that the majority of phenolic compounds contained in FFS did not exhibit mutagenicity toxicity,hepatotoxicity,skin sensitization,or blood-brain barrier penetration,indicating a favorable level of biosafety.Overall,our study provides a new insight into the further utilization of Se-enriched Brassica napus L.in foods.

Klebsiella as an α-tocopherol source facilitating Lactobacillus plantarum fermentation in rice straw silage

Silage serves as the indispensable diet of ruminants,the increasing mechanism of α-tocopherol during silage making is unclear.Rice straw lacks chlorophyll after harvesting the grain,this can eliminate the impact of tocopherols formed by the breakdown of chlorophyll.Here,we explored the α-tocopherol source,its influencing factor,and its relationship with dominant lactic acid bacteria in rice straw silage treated without or with different additives(sodium benzoate,Lactobacillus plantarum,cell wall degrading enzymes,the combination of L.plantarum and cell wall degrading enzymes)and vacuum times(5,8,11,and 14 s)after ensiling for 42 d.We found that the pathogenic Klebsiella was traced as the source of increasedα-tocopherol in rice straw silage.The residue air in the silo,pH value,and additive variety had impacts on Klebsiella activity,which was strongly active at levels of residue air in the silo and pH that were high.As an acidic niche creator,L.plantarum was more effective than sodium benzoate in restraining Klebsiella.Despite having a low acidity tolerance,Klebsiella was still present in rice straw silage treated with L.plantarum.The relationship between Klebsiella and L.plantarum was that Klebsiella could affordα-tocopherol to the multiplication of L.plantarum and residue capsular polysaccharide protected Klebsiella from escaping the extinction in rice straw silage.

Transcriptomic analysis of molecular mechanisms underlying the biodegradation of organophosphorus pesticide chlorpyrifos by Lactobacillus delbrueckii ssp.bulgaricus in skimmed milk

Bioremediation of organophosphorus pesticides in contaminated foodstuffs using probiotics has been increasingly under the spotlight in recent years,though the biodegradation mechanism and derived intermediate products remain unclear.This study aimed to help fill this knowledge gap and examined the degradation mechanism of organophosphorus pesticide,chlorpyrifos,in milk by Lactobacillus delbrueckii ssp.bulgaricus using gas chromatography-tandem mass spectrometry(GC-MS/MS)combined with transcriptome analysis.After the strain was cultured for 20 h in the presence of chlorpyrifos,differential expressions of 383 genes were detected,including genes probably implicated during chlorpyrifos degradation such as those related to hydrolase,phosphoesterase,diphosphatase,oxidoreductase,dehydratase,as well as membrane transporters.GC-MS/MS analysis revealed the changes of secondary metabolites in L.bulgaricus during milk fermentation due to chlorpyrifos stress.6-Methylhexahydro-2H-azepin-2-one,2,6-dihydroxypyridine and methyl 2-aminooxy-4-methylpentanoate as intermediates,along with the proposed pathways,might be involved in chlorpyrifos biodegradation by L.bulgaricus.

Identification,Characterization,and Probiotic Potentials of Lactobacillus pentosus SF-1

In recent years probiotics have been considered as a potential substitution of antibiotics to control pathogens and treat infectious diseases in aquaculture.In the present study a strain of Lactobacillus pentosus,named as L.pentosus SF-1,was isolated from waters in aquaculture.The species identification of this strain was conducted by 16S rRNA sequence,and the physiological and biochemical characteristics of this strain were assessed.Furthermore,the virulence,antibiotic sensitivity,cell surface characteristics and acid/base-resistance of L.pentosus SF-1 were determined to evaluate the probiotic potentials of this strain.Specifically,L.pentosus SF-1 is sensitive to most common antibiotics,and no hemolysin was generated from it,indicating the safety of this strain to hosts.In addition,L.pentosus SF-1 was able to tolerate the artificial gastric juice at pH 3 for 4 h and the artificial intestinal fluid at pH 6.8 or 8.0 for 6 h.Moreover,the analysis of self-aggregation and the adhesion of L.pentosus SF-1 to organic solvents suggested a high potential of L.pentosus SF-1 to inhabit the hosts,which was confirmed by testing the colonization of L.pentosus SF-1 in germ-free zebrafish.Interestingly,L.pentosus SF-1 displayed a high bactericidal activity against several bacterial pathogens.Consistently,the incubation of L.pentosus SF-1 significantly promoted the expression of antimicrobial components in zebrafish,contributing to the protection of the fish from E.tarda infection in vivo.Taken together,the probiotic strain L.pentosus SF-1 could be applied as anti-infection reagent in aquaculture.

基于转录组学探究Lactobacillus plantarum 6A促进二乙基亚硝胺形成的机制

乳酸菌是食品工业和人体肠道常见微生物,可促进强致癌物亚硝胺的合成,而其促进机制尚待揭示,严重制约了发酵食品安全的提升和益生菌产品的推广。该文考察植物乳杆菌(Lactobacillus plantarum)6A对二乙基亚硝胺(N-nitrosodiethylamnie,NDEA)促进作用在不同环境中的变化趋势,以转录组技术进一步探究促进作用的关键基因和形成途径,构建其机制网络。结果表明,NDEA胁迫L.plantarum 6A通过上调嘌呤核苷酸合成/代谢(关键基因purL、purK、purC、purB、purA)、核黄素合成/代谢(ribBA、ribH、ribE)、双组分系统途径(dltD、dltB、dltA)的基因表达,产生NDEA前体物,如富含氮元素的嘌呤、核黄素及丙氨酸,从而促进NDEA形成;还可能通过核黄素合成/代谢以及双组分系统途径间接催化亚硝化反应,加速NDEA的形成。

嗜酸乳杆菌(Lactobacillus acidophilus)合成纳米硒特性研究

乳酸菌具有还原亚硒酸钠为纳米硒的能力。为了采用更加环境友好的方式获得纳米硒颗粒,本研究首先探索了培养基中加硒浓度、加硒时间,以及培养时长对嗜酸乳杆菌(Lactobacillus acidophilus)合成纳米硒的影响,随后对所产的纳米硒颗粒的粒径、zeta电位及抑菌活性进行研究。结果表明,当培养基中硒含量为0~600μg/mL时,硒浓度越高,转化得到的纳米硒越多;当培养基中硒浓度高于600μg/mL时,发酵液中的纳米硒含量反而减少。在嗜酸乳杆菌生长的对数中前期,即第6 h时添加亚硒酸钠,更有利于纳米硒的合成。而培养至32 h后,纳米硒几乎不再继续合成。通过扫描电镜及粒径和电位仪分析发现,嗜酸乳杆菌所产的纳米硒颗粒呈球形,且超声破碎有助于其释放;纳米硒颗粒带负电荷,电位绝对值为40~50 mV,粒径大小较多分布于170~210 nm,具有良好的稳定性。抑菌实验结果表明,嗜酸乳杆菌还原亚硒酸钠所产的纳米硒对大肠杆菌、沙门氏菌、金黄色葡萄球菌和枯草芽孢杆菌的生长均具有抑制作用。综上,嗜酸乳杆菌可以将亚硒酸钠还原合成纳米硒,且所产的纳米硒颗粒具有良好的抑菌活性。

Lactobacillus from fermented bamboo shoots prevents inflammation in DSS-induced colitis mice via modulating gut microbiome and serum metabolites

Fermented bamboo shoots(FBS)is a region-specific food widely consumed in Southwestern China,with Lactobacillus as the predominant fermenting bacteria.However,the probiotic potential of Lactobacillus derived from FBS reminds largely unexplored,especially for diseases with a low prevalence in areas consuming FBS,namely,inflammatory bowel disease.In this study,Lactiplantibacillus pentosus YQ001 and Lentilactobacillus senioris YQ005 were screening by in vitro probiotic tests to further investigate the probioticlike bioactivity in dextran sulfate sodium(DSS)-induced ulcerative colitis(UC)mouse.They exhibited more positive probiotic effects than Lactobacillus rhamnosus GG in preventing intestinal inflammatory response.The results revealed that both strains improved the abundance of deficient intestinal microbiota in UC mice,including Muribaculaceae and Akkermansia.In the serum metabolome,they modulated the DSS-disturbed levels of metabolites,with significant increment of cinnamic acid.Meanwhile,they reduced the expression levels of interleukin-1β(IL-1β),interleukin-6(IL-6)inflammatory factors and increased zonula occludens-1(ZO-1),Occludin,and cathelicidin-related antimicrobial peptide(CRAMP)in the colon.Consequently,these results demonstrated that Lactobacillus spp.isolates derived from FBS showed promising probiotic activity based on the gut microbiome homeostasis modulation,anti-inflammation and intestinal barrier protection in UC mice.

Effect of dietary supplement of inactivated Lactobacillus plantarum Ep-M 17 on growth performance,immune response,disease resistance,and intestinal microbiota in Penaeus vannamei

Our previous study found that feeding with Lactobacillus plantarum Ep-M17 could effectively affect the growth performance,immune response,and gut microbiota of Penaeus vannamei.However,high temperature and pressure during feed pelletizing is the main problem that can lead to a decrease in the activity of probiotics or cause their inactivation.Further investigation needs to investigate whether inactivated Ep-M17 can exert similar effects as live Ep-M17.Therefore,we evaluated the effects of inactivated L.plantarum Ep-M17 on growth performance,immune response,disease resistance,and gut microbiota in P.vannamei.Results show that adding inactivated Ep-M17 to the feed also promoted body weight gain and increased relative immune protection in shrimp.Also,histological examination revealed that the administration of inactivated Ep-M17 led to improvements in the density and distribution of microvilli in the intestines and enhancements in the abundance of B and R cells in the hepatopancreas.Additionally,the inactivated Ep-M17 supplementation resulted in increased activity levels of nutrient immune-related enzymes in both the shrimp hepatopancreas and intestines.Moreover,it stimulated the expression of Lvlec,PEN-3a,Crustin,LGBP,Lysozyme,and proPo genes in both the hepatopancreas and intestines.Furthermore,the inactivated Ep-M17 also increased bacterial diversity in the gut of shrimp and promoted the abundance of specific flora,facilitating the host organism’s metabolism and immunity to improve the disease resistance of shrimp.Therefore,supplementation of inactivated L.plantarum Ep-M17 in shrimp diets can exert similar effects as live L.plantarum Ep-M17 effectively improving growth performance,gut microbiota,immune response,and disease resistance in P.vannamei.

Improved viability of trehalose on Lactobacillus plantarum embedded with whey protein concentrate/pullulan in simulated gastrointestinal conditions and its application in acid juice

Trehalose(TRE)was used to improve the gastrointestinal tolerance of Lactobacillus plantarum embedded with whey protein concentrate/pullulan(WPC/PUL)hydrogel and the embedded L.plantarum was applied to juice.The study indicated that 5%TRE significantly increased the viable counts of L.plantarum embedded in WPC/PUL hydrogel from(8.83±0.03)to(9.14±0.04)(lg(CFU/g))in simulated gastric juice(SGJ)and from(9.13±0.04)to(9.38±0.04)(lg(CFU/g))in simulated intestinal juice,respectively.The addition of TRE improved the glass transition temperature of WPC/PUL hydrogel and decreased the hardness and its solubility in SGJ,which may be responsible for the improved protection of WPC/PUL hydrogels on L.plantarum.In addition,TRE increased the viable counts of L.plantarum in WPC/PUL probiotic microcapsule juice at low pH and high temperature during storage.

Lactobacillus plantarum AR495 improves stress-induced irritable bowel syndrome in rats by targeting gut microbiota and Mast cell-PAR2-TRPV1 signaling pathway

Probiotics have great potential in regulating intestinal pain.In this study,the effects of Lactobacillus plantarum AR495 on the visceral sensitivity and gut microbiota of irritable bowel syndrome(IBS)rats were studied.The results showed that tryptase released after mast cell activation and degranulation plays a key role in visceral pain,and L.plantarum AR495 reduced the stimulation of colonic mast cells and the expression of protease-activated receptor 2(PAR2)and TRPV1 in dorsal root ganglia.Research further showed that supplementation with L.plantarum AR495 increased the level of short-chain fatty acids(SCFAs)and enhanced the barrier function of the colon.In addition,the microbiota analysis of the colon indicated that L.plantarum AR495 promoted the proliferation of Bifidobacterium and inhibited the proliferation of Lachnospiraceae,which alleviated the imbalance of the intestinal microbiota caused by IBS to a certain extent.In total,L.plantarum AR495 might reduce visceral sensitivity through the Mast cell-PAR2-TRPV1 signaling pathway by maintaining the homeostasis of the intestinal barrier.