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。

饲用发酵乳酸杆菌(Lactobacillus fermentum)生物学特性的研究

在体外研究了1株仔猪源的发酵乳酸杆菌(Lactobacillusfermentum)的生长曲线、耐热存活率、耐酸存活率、贮藏存活率等生物学特性,采用均匀设计法优化发酵乳酸杆菌的发酵培养基。结果表明,发酵乳酸杆菌的浓度在2h之后从105个数量级迅速上升,到第24h菌体浓度达到最高值,第28h之后,活菌浓度开始缓慢下降到1011数量级以下。pH2.0处理6h的存活率为80.9%,经过1个月贮藏存活率为78.4%,75℃处理15min之后存活率为45.1%。优化的发酵参数为:时间:20h;葡萄糖:10g/L;蔗糖:60g/L;胰蛋白胨:30g/L;酵母浸粉:30g/L;柠檬酸铵:12g/L。研究证明该发酵乳酸杆菌具有良好的生长繁殖性能和较强的抗逆性,在仔猪饲料中可以用作益生素菌种。

Lactobacillus fermentum F6的增殖培养基优化及高密度发酵的研究

对分离自少数民族传统乳制品中的Lactobacillus fermentum F6菌种的增殖培养基进行优化,并对其高密度发酵条件进行探索。通过测定不同组成培养基中菌体在600nm波长下的光密度和发酵液在不同发酵条件下的活菌数,得到最适增殖培养基配方及其高密度发酵条件。增殖培养基配方为:蔗糖62.0g/L、酵母粉35.5g/L、大豆蛋白胨12.0g/L、柠檬酸1.35g/L、柠檬酸钠22g/L、MgSO4·7H2O2g/L、MnSO4·5H2O100mg/L、Tween-801g/L。在5L发酵罐中,Lactobacillus fermentum F6经优化发酵条件,其活菌数可达到2.30×1010CFU/mL,加入保护剂经冷冻干燥后活菌数可达到1.45×1011CFU/g,存活率为79.11%。中试培养液中活菌数可达1.02×1010CFU/mL,存活率为58%。以上优化的增殖培养基和高密度发酵条件为Lactobacillus fermentum F6的工业化生产奠定了基础。

Lactobacillus fermentum Zhao的小鼠抗皮肤老化效果

本文对Lactobacillus fermentum Zhao(LF-Zhao)的抗老化效果进行研究。体外抗氧化实验结果显示LF-Zhao具有较强的DPPH自由基和·OH清除能力。进一步的动物实验表明,LF-Zhao可以提高D-半乳糖诱导氧化小鼠血清和皮肤组织中的SOD、GSH-Px水平和降低NO、MDA水平,且随着LF-Zhao浓度的增加效果更为明显。通过RT-PCR实验分析小鼠皮肤组织发现,LF-Zhao能上调氧化小鼠皮肤的n NOS、e NOS、Mn-SOD、Gu/Zn-SOD、CAT mRNA表达和下调i NOS表达,高浓度的LF-Zhao使以上表达最接近正常组小鼠。通过这些结果可以得出LF-Zhao具有良好的皮肤抗老化作用。

秦川牛宰后成熟过程中线粒体Tu翻译延长因子对牛肉持水性的影响

探究秦川牛宰后成熟过程中线粒体Tu翻译延长因子(mitochondrial Tu translation elongation factor,TUFM)表达对肉的持水性影响。以秦川牛背最长肌为研究对象,测定4℃不同成熟时间下的pH值、贮藏损失、离心损失、蒸煮损失、水分分布、肌原纤维蛋白等指标变化情况,测定不同成熟时间(0、96、192 h)下TUFM表达量及其含量、Beclin1蛋白表达量。结果显示:在秦川牛宰后成熟期间,肌原纤维蛋白发生降解,TUFM的表达量与Beclin1蛋白表达量和牛肉的持水性存在密切关系,其中蛋白质组学测定的TUFM表达量变化与TUFM含量变化趋势一致,Beclin1蛋白表达量、贮藏损失、离心损失、蒸煮损失整体均呈先上升后下降趋势,pH值呈先下降后上升趋势;Pearson相关性分析表明,牛背最长肌中TUFM表达量与低场核磁共振峰面积比P_(2b)、Beclin1蛋白表达量呈极显著正相关(P<0.01),与贮藏损失、离心损失、蒸煮损失呈显著正相关(P<0.05),与P_(21)呈极显著负相关(P<0.01),与P_(22)呈显著负相关(P<0.05),与pH值无显著相关性(P>0.05)。通过蛋白质组学鉴定出23种与TUFM相关的差异蛋白,通过基因本体论、京都基因与基因组百科全书通路分析发现,差异蛋白可通过多种途径参与能量代谢,进而介导细胞自噬;对差异蛋白和持水性指标进行Pearson相关性分析发现,有5种差异蛋白(ATP5F1D、EEF1A2、GSPT1、NDUFB5、SUCLG1)与持水性指标具有显著相关性(P<0.05、P<0.01)。分析可知,包括TUFM在内,共6种蛋白主要通过能量代谢和氧转运等途径正向或负向影响细胞自噬,从而影响肉的持水性。

Mucosal adhesion and anti-inflammatory effects of Lactobacillus rhamnosus GG in the human colonic mucosa: A proof-of-concept study

AIM To investigate the adhesion and anti-inflammatory effects of Lactobacil us rhamnosus GG (LGG) in the colonic mucosa of healthy and ulcerative colitis (UC) patients, both in vivo and ex vivo in an organ culture model.METHODS For the ex vivo experiment, a total of 98 patients (68 UC patients and 30 normal subjects) were included. Endoscopic biopsies were collected and incubated with and without LGG or LGG-conditioned media to evaluate the mucosal adhesion and anti-inflammatory effects [reduction of tumor necrosis factor alpha (TNFα) and interleukin (IL)-17 expression] of the bacteria, and extraction of DNA and RNA for quantification by real-time (RT)-PCR occurred after the incubation. A dose-response study was performed by incubating biopsies at "regular", double and 5 times higher doses of LGG. For the in vivo experiment, a total of 42 patients (20 UC patients and 22 normal controls) were included. Biopsies were taken from the colons of normal subjects who consumed a commercial formulation of LGG for 7 d prior to the colonoscopy,and the adhesion of the bacteria to the colonic mucosa was evaluated by RT-PCR and compared with that of control biopsies from patients who did not consume the formulation. LGG adhesion and TNFα and IL-17 expression were compared between UC patients who consumed a regular or double dose of LGG supplementation prior to colonoscopy.RESULTS In the ex vivo experiment, LGG showed consistent adhesion to the distal and proximal colon in normal subjects and UC patients, with a trend towards higher concentrations in the distal colon, and in UC patients, adhesion was similar in biopsies with active and quiescent inflammation. In addition, bioptic samples from UC patients incubated with LGG conditioned media (CM) showed reduced expression of TNFα and IL-17 compared with the corresponding expression in controls (P < 0.05). Incubation with a double dose of LGG increased mucosal adhesion and the anti-inflammatory effects (P < 0.05). In the in vivo experiment, LGG was detectable only in the colon of patients who consumed the LGG formulation, and bowel cleansing did not affect LGG adhesion. UC patients who consumed the double LGG dose had increased mucosal concentrations of the bacteria and reduced TNFα and IL-17 expression compared with patients who consumed the regular dose (48% and 40% reduction, respectively, P < 0.05).CONCLUSION In an ex vivo organ culture model, LGG showed consistent adhesion and anti-inflammatory effects. Colonization by LGG after consumption for a week was demonstrated in vivo in the human colon. Increasing the administered dose increased the adhesion and effectiveness of the bacteria. For the first time, we demonstrated that LGG effectively adheres to the colonic mucosa and exerts antiinflammatory effects, both ex vivo and in vivo.

Structural Characterization of Glucan Produced by Lactobacillus sake L-7 from Sausage

A linear glucan was produced by Lactobacillus sake L-7 isolated from homemade sausage. Cultivation of the strain in Man–Rogosa–Sharpe(MRS) medium containing 50 g/L sucrose yielded 5.3 g/L of purified exopolysaccharide(EPS). The EPS was characterized by gas chromatography(GC), Fourier-transform infrared(FT-IR) spectroscopy, high-performance sizeexclusion chromatography(HPSEC), nuclear magnetic resonance(NMR) spectroscopy, and scanning electron microscopy(SEM). The monosaccharide composition of the EPS was glucose, and its molecular weight was 1 × 10~7 Da. The FT-IR and NMR spectra revealed that the L-7 EPS was a linear glucan with α-(1 → 6) glucosidic bonds. SEM images of the dried EPS revealed a hollow tubular structure. The water solubility index and water holding capacity of L-7 EPS were 96 and 272%, respectively. The results of hydrolysis indicated that L-7 EPS was not susceptible to hydrolysis by physiological barriers and can be used as a soluble dietary fiber with health benefits. All these characteristics suggest that L-7 EPS might have potential applications in the food, cosmetic, and pharmaceutical industries.

Effect of Lactobacillus rhamnosus HN001 and Bifidobacterium longum BB536 on the healthy gut microbiota composition at phyla and species level: A preliminary study

AIMTo evaluate the ability of Lactobacillus rhamnosus HN001 and Bifidobacterium longum BB536 to colonize the intestinal environment of healthy subjects and modify the gut microbiota composition.METHODSTwenty healthy Italian volunteers, eight males and twelve females, participated in the study. Ten subjects took a sachet containing 4 × 109 colony-forming units (CFU) of Bifidobacterium longum BB536 and 109 CFU of Lactobacillus rhamnosus HN001, 30 min before breakfast (pre-prandial administration), while ten subjects took a sachet of probiotic product 30 min after breakfast (post-prandial administration). The ability of Lactobacillus rhamnosus HN001 and Bifidobacterium longum BB536 to colonize human gut microbiota was assessed by means of quantitative real-time PCR, while changes in gut microbiota composition were detected by using Ion Torrent Personal Genome Machine.RESULTSImmediately after 1-mo of probiotic administration, B. longum BB536 and L. rhamnosus HN001 load was increased in the majority of subjects in both pre-prandial and post-prandial groups. This increase was found also 1 mo after the end of probiotic oral intake in both groups, if compared to samples collected before probiotic consumption. At phyla level a significant decrease in Firmicutes abundance was detected immediately after 1-mo of B. longum BB536 and L. rhamnosus HN001 oral intake. This reduction persisted up to 1 mo after the end of probiotic oral intake together with a significant decrease of Proteobacteria abundance if compared to samples collected before probiotic administration. Whereas, at species level, a higher abundance of Blautia producta, Blautia wexlerae and Haemophilus ducrey was observed, together with a reduction of Holdemania filiformis, Escherichia vulneris, Gemmiger formicilis and Streptococcus sinensis abundance. In addition, during follow-up period we observed a further reduction in Escherichia vulneris and Gemmiger formicilis, together with a decrease in Roseburia faecis and Ruminococcus gnavus abundance. Conversely, the abundance of Akkermansia muciniphila was increased if compared to samples collected at the beginning of the experimental time courseCONCLUSIONB. longum BB536 and L. rhamnosus HN001 showed the ability to modulate the gut microbiota composition, leading to a significant reduction of potentially harmful bacteria and an increase of beneficial ones. Further studies are needed to better understand the specific mechanisms involved in gut microbiota modulation.

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。

Lactobacillus plantarum inhibits epithelial barrier dysfunction and interleukin-8 secretion induced by tumor necrosis factor-a

AIM： To determine whether Lactobacillus plantarum can modify the deleterious effects of tumor necrosis factor-α （TNF-α） on intestinal epithelial cells. METHODS： Caco-2 cells were incubated with TNF-α alone or in the presence of L. plantarum. Transepithelial electrical resistance was used to measure epithelial barrier function. Interleukin 8 （IL-8） secretion by intestinal epithelial cells was measured using an ELISA. Cellular lysate proteins were immunoblotted using the anti-extracellular regulated kinase （ERK）, anti-phospho- ERK and anti-IκB-α. RESULTS： A TNF-α-induced decrease in transepithelial electrical resistance was inhibited by L. plantarum. TNF- α-induced IL-8 secretion was reduced by L. plantarum. L. plantarum inhibited the activation of ERK and the degradation of IκB-α in TNF-a-treated Caco-2 cells. CONCLUSION： Induction of epithelial barrier dysfunction and IL-8 secretion by TNF-α is inhibited byL. plantarum. Probiotics may preserve epithelial barrier function and inhibit the inflammatory response by altering the signal transduction pathway.

Study Bacteriocin Production and Optimization Using New Isolates of <i>Lactobacillus</i>spp. Isolated from Some Dairy Products under Different Culture Conditions

Lactobacilli belong to the group of lactic acid bacteria (LAB), that have several distinguished abilities such as production of lactic acid, enzymes such as β-Galactosidase and natural antimicrobial substances called bacteriocins. Bacteriocin is a biopreservative agent potential of suppressing growth of some contaminant bacteria in food industry but its commercial availability is limited and costly. The study aimed to select isolates of Lactobacillus spp. potential for producing bacteriocins to suppress the growth of Escherichia coli ATCC 25922 and Bacillus subtilis NCIB3610, and to optimize the process of bacteriocin production. Results obtained in this study showed that L. acidophilus isolate CH1 was selected as the best candidate for bacteriocin among the four isolates that tested. The largest amounts of the bacteriocins were synthesized only in MRS medium was supplemented with K2HPO4 (1.0%), Tween 80 (1%), Beef extract (1%), glucose, cyctein and peptone extract (1%). The optimization of culture conditions for bacteriocin production areas showed that corn steep liquor medium was the best medium for all isolates against Bacillus subtilis while no effect was observed on Escherichia coli ATCC 25922 except when used MRS medium. The optimum conditions for bacteriocin production were pH 6.0, temperature 34?C with 4% Phenyl acetamide showing the greatest growth inhibition areas.

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.

Lactobacillus crispatus M206119 exacerbates murine DSS-colitis by interfering with inflammatory responses

AIM： TO investigate the role of Lactobacillus crispatus （L. crispatus） strain China Center for Type Culture Col- lection （CCTCC） M206119 in intestinal inflammation.METHODS： Forty 8-wk-old Balb/c mice （20± 2 g） were divided into four groups of 10 mice each. Three groups that had received dextran sulfate sodium （DSS） were administered normal saline, sulfasalazine or CCTCC M206119 strain, and the fourth group received none of these. We assessed the severity of colitis using a disease activity index, measured the colon length and weight, collected stools and mesenteric lymph nodes for bacterial microflora analysis. One centimeter of the proximal colon, middle colon and distal colon were collected and fixed in 10% buffered formalin, dehydrated in ethanol, and embedded in paraffin. Interleukin （IL）- 1β, IL-6 and tumor necrosis factor （TNF）-α expression was detected using reverse transcription polymerase chain reaction. Protective factors zonula occludens （ZO）-1 and β-defensin 2 were detected by immunoblot-ting. The features of CCTCC M206119 strain were identified based on morphology, biochemical profile, and 16S RNA sequencing.RESULTS： DSS-colitis animals treated with CCTCC M206119 had markedly more severe disease, with greater weight loss, diarrhea, fecal bleeding, and shortened colon length. In addition, the CCTCC-M206119- treated group had comparatively higher histologi- cal scores and more neutrophil infiltration than the controls. Expression of protective factors ZO-1 and β-defensin 2 was downregulated due to destruction of the mucosal barrier after CCTCC M206119 strain treatment. An in vitro assay demonstrated that CCTCC M206119 strain increased the nuclear translocation of nuclear factor-κB in epithelial cells. Intestinal proinflam- matory or anti-inflammatory cytokine responses were evaluated. Proinflammatory colonic cytokine （IL-Iβ, IL-6 and TNF-α） levels were clearly increased in CCTCC- M206119-treated animals, whereas anti-inflammatory colonic cytokine （IL-10） level was lowered compared with saline or 5-aminosalicylic-acid-treated DSS-colitis mice. Next, CCTCC M206119 strain was characterized as 1. crispatus by microscopic morphology, biochemical tests and 16S rRNA gene level.CONCLUSION： Not all lactobacilli are beneficial for in- testinal inflammation, and L. crispatus CCTCC M206119 strain is involved in exacerbation of intestinal inflamma- tion in DSS-colitis mice.

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.

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.

Antioxidant effect of Lactobacillus fermentum HFY02-fermented soy milk on D-galactose-induced aging mouse model

This study aimed to investigate the antioxidant effect of soybean milk fermented by a new type of Lactobacillus fermentum(LF-HFY02)by using D-galactose induced aging mice model.Firstly,the optimal fermentation conditions was screened out by detecting the effects of different fermentation temperature and time on the active components and antioxidant activity of soybean milk in viro.And then unfermented soybean milk and the soybean milk fermented by different Lactobacillus was given by gavage to D-galactose-induced aging mouse.The activities of GSH,GSH-Px,SOD,CAT and T-AOC in serum,brain and liver of soybean milk fermented by LF-HFY02 were significantly increased,while the content of MDA and the level of AGEs in hippocampal were significantly decreased compared with D-galactose induced group.Further more,the mRNA expression of GSH and SOD in mouse liver were obviously up-regulated by soybean milk fermented by LF-HFY02.The skin tissue structure of mice in the LF-HFY02 fermented soybean milk group was more complete,the collagen fibers were increased and arranged orderly and liver inflammation has improved compared with the model group.And Western blot analysis showed that LF-HFY02 effectively upregulated EGFR,SOD and GSH protein expression in mouse liver.These findings suggest that LF-HFY02 can effectively prevent D-galactose-induced oxidation and aging in mice,and the effect was even better than that of the Lactobacillus delbruechii subsp.bulgaricus and vitamin C.Thus,LF-HFY02 may be potentially employed as a probiotic strain.In conclusion,soybean milk fermented by LF-HFY02 can increase the content of antioxidant factors and the activity of antioxidant enzymes by regulating gene and protein expression,and finally inhibit the process of tissue cell peroxidation,and improve the oxidative damage of mouse skin and liver.The results could provide a basis for the research and development and industrial production of probiotic-related fermented soybean milk products.

A Two-stage pH and Temperature Control with Substrate Feeding Strategy for Production of Gamma-aminobutyric Acid by Lactobacillus brevis CGMCC 1306

Methods to optimize the production of gamma-aminobutyric acid （GABA） by Lactobacillus brevis CGMCC 1306 were investigated. Results indicated that cell growth was maximal at pH 5.0, while pH 4.5 was pref-erable to GABA formation. The optimal temperature for cell growth （35 °C） was lower than that for GABA forma-tion （40 °C）. In a two-stage pH and temperature control fermentation, cultures were maintained at pH 5.0 and 35 °C for 32 h, then adjusted to pH 4.5 and 40 °C, GABA production increased remarkably and reached 474.79 mmol·L-1 at 72 h, while it was 398.63 mmol·L-1 with one stage pH and temperature control process, in which cultivation con-ditions were constantly controlled at pH 5.0 and 35 °C. In order to avoid the inhibition of cell growth at higher L-monosodium glutamate （L-MSG） concentrations, the two-stage control fermentation with substrate feeding strat-egy was applied to GABA production, with 106.87 mmol （20 g） L-MSG supplemented into the shaking-flask at 32 h and 56 h post-inoculation separately. The GABA concentration reached 526.33 mmol·L-1 at 72 h with the fer-mentation volume increased by 38%. These results will provide primary data to realize large-scale production of GABA by L. brevis CGMCC 1306.

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.