Study on the Influence of Tea Extract on Probiotics in Skim Milk: From Probiotics Propagation to Metabolite

In this study, the influence of tea extract (TE) on the growth of probiotics in skim milk was examined. Lactobacillus plantarum ST‐III, Bifidobacterium bifidum Bb02, Lactobacillus acidophilus NCFM, and Lactobacillus rhamnosus GG were used in this study. The introduction of TE in milk significantly stimulated the propagation and acidification of L. rhamnosus GG and L. acidophilus NCFM. The antioxidant capacities and the total free amino acid contents of all fermented milk products were enhanced by the addition of TE; however, there were different antioxidant properties and free amino acid contents of fermented milk samples fermented by different bacteria. With a 9% (w/w) level, the fermentation with L. rhamnosus GG and L. acidophilus NCFM showed larger numbers of viable cells and faster acidifying rates, as well as excellent antioxidant capacity and abundant free amino acids.  The stimulative effects of TE on probiotics can be considered for industrial purposes and has practical implications for commercial applications.     

皮肤微生物与益生菌在皮肤疾病诊疗中的应用

皮肤是人体最大的器官,定殖着复杂的微生物群落。大部分微生物是对人体无害的,甚至有些是有益的。皮肤微生物在皮表所接触的外环境影响下,形成了其独特且复杂的菌群结构,同时也受到人体固有免疫和获得性免疫系统的影响,与人体免疫系统共同进化。伴随着分子生物学的发展,皮肤上复杂与庞大的常驻菌群被逐渐认知。对皮肤微生物的深入了解不仅帮助人们了解微生物与皮肤屏障的相互作用机制,也为微生物引起的皮肤疾病的治疗提供有效的策略。本文综述了近年来国内外有关皮肤微生物的研究成果,以及在皮肤疾病和微生物紊乱导致的相关疾病中,益生菌在诊疗过程中的应用。     

Beneficial effects of probiotic cholesterol-lowering strain of Enterococcus faecium WEFA23 from infants on diet-induced metabolic syndrome in rats

The aim of this study was to select probiotic Enterococcus strains that have the potential to improve metabolic syndrome (MS). Ten Enterococcus strains isolated from healthy infants were evaluated for their probiotic properties in vitro, and Enterococcus faecium WEFA23 was selected due to its cholesterol removal ability (1.89 ± 0.07 mg/10¹⁰ cfu), highest glycodeoxycholic acid-hydrolase activity (1.86 ± 0.01 U/mg), and strong adhesion capacity to Caco-2 cells (17.90 ± 0.19%). The safety of E. faecium WEFA23 was verified by acute oral administration in mice, and it was found to have no adverse effects on general health status, bacterial translocation, and gut mucosal histology. Moreover, the bene?cial effects of E. faecium WEFA23 on high-fat diet-induced MS in rats were investigated, and we found WEFA23 signi?cantly decreased body weight, serum lipid levels (total cholesterol, triacylglycerols, and low-density lipoprotein cholesterol), blood glucose level, and insulin resistance in rats fed with a high-fat diet. This indicated that administration of E. faecium WEFA23 improved almost all key markers of MS, including obesity, hyperlipidemia, hyperglycemia, and insulin resistance. Our results supported E. faecium WEFA23 as a candidate for cholesterol-lowering dairy products and improvement of MS. Our research provided novel insights on Enterococcus as a strategy to combat MS.     

Health-promoting benefits of low-fat akawi cheese made by exopolysaccharide-producing probiotic Lactobacillus plantarum isolated from camel milk

Lactic acid bacteria isolated from camel milk exhibit remarkable probiotic and exopolysaccharide (EPS)-producing characteristics. The health-promoting benefits of exopolysaccharide-producing probiotic Lactobacillus plantarum isolated from camel milk used for making low-fat akawi cheese were investigated. Three low-fat akawi cheeses were made using traditional culture (non-EPS-producing, EPS^?), commercial EPS-producing (MEPS⁺), and camel milk EPS-producing (CEPS⁺) cultures. α-Amylase and α-glucosidase inhibitory activities, antioxidant activities, angiotensin-converting enzyme (ACE) inhibition, and antiproliferative activity were determined. Cheese made with CEPS⁺ culture exhibited comparable α-amylase inhibition to that of cheeses made with MEPS⁺. Scavenging rates of cheese made with EPS⁺ cultures were higher than those of cheese made with EPS^? cultures. The percentage of α-glucosidase inhibition ranged from >45% at 0 d to ～55% at 21 d of storage. After 7 d of storage, the scavenging rate in CEPS⁺ cheese increased >60% by ABTS assay [2,2'-azino-bis(3-ethylbenzo-thiazoline-6-sulfonic acid)] and >20% by DPPH assay (1,1-diphenyl-2-picrylhydrazyl). Throughout storage, cheese made with EPS⁺ cultures showed higher ACE-inhibition activity compared with EPS^? cultures. Cheese made with CEPS⁺ showed ACE inhibition >70% after 7 d of storage. Antiproliferation activity of CEPS⁺ cheese increased from 38 to 48% during 7 d of storage and was maintained above 45% with prolonged storage. Low-fat akawi cheese produced with these cultures exhibited similar or greater health-promoting benefits compared with cheese made using commercial starter cultures. Therefore, incorporation of these cultures in food is promising for commercial uses.     

Foam‐Mat Freeze‐Drying of Bifidobacterium longum RO175: Viability and Refrigerated Storage Stability

Foaming as a pretreatment was used prior to freeze‐drying of Bifidobacterium longum RO175 to investigate the potential acceleration of the drying rate and increase in microorganism viability after the process. A study on storage of foamed and nonfoamed freeze‐dried products at 4 °C completed this study. B. longum RO175 in foamed medium could be freeze‐dried in 1/7 to 1/4 of the time required for nonfoamed suspensions. In addition, foamed suspensions presented higher viability immediately after freeze‐drying (13.6% compared to 12.81 % or 11.46%, depending on the cryoprotective media). Refrigerated storage led to a reduction in B. longum RO175 viability for all tested protective agents (foamed and nonfoamed). No correlation between glass transition temperature and stability of probiotic powders was observed during storage. In addition, lower viability after 56 d of storage was observed for foamed materials, probably due to foam porous structure and higher hygroscopicity, and oxygen presence and moisture pickup during storage.     

Sheep Milk: Physicochemical Characteristics and Relevance for Functional Food Development

Sheep milk has a high nutritional value and high concentrations of proteins, fats, minerals, and vitamins, as compared to the milks of other domestic species. The physicochemical and nutritional characteristics of sheep milk can be advantageous for the manufacture of products containing prebiotic ingredients and/or probiotic bacteria, which are major categories in the functional food market. Following this technological trend, this review will address the characteristics and advantages of sheep milk as a potentially functional food, as well as the development of sheep milk dairy products containing prebiotics and/or probiotics.     

适于益生菌发酵的青稞酶解液制备工艺优化

采用程序升温法对青稞进行酶解,以还原糖含量为响应值,采用响应面法对青稞酶解液制备工艺进行了优化。结果表明:按料水比1:15(g/mL)溶解青稞粉,经糊化后冷却至45℃,加入8.9U/g·青稞的α-淀粉酶和原料质量2.0%,3.5%的糖化酶、菠萝蛋白酶,保温20 min后升温到60℃酶解,直至碘试液体呈无色,过滤得到青稞酶解液,其还原糖、氨基酸态氮含量分别为5.68%、0.47g/L,可作为制备益生菌发酵青稞饮料的良好基质。