Comparative genomic analysis for the presence of potential enterococcal virulence factors in the probiotic Enterococcus faecalis strain Symbioflor 1

Enterococci are members of the natural microbiota of animal and human intestinal tracts and are capable of causing opportunistic infections. They are also used as starter cultures in the food industry as well as in health supplements and probiotics by the pharmaceutical industry. This Janus-faced status requires a careful evaluation on the basis of pathogenic traits to ensure the safety of the strain used to produce food and pharmaceuticals. We performed gapped-genome sequencing of a probiotic strain Enterococcus faecalis Symbioflor 1 and present initial results deriving from comparative genome analysis with that of the previously sequenced pathogenic clinical isolate E. faecalis V583. There was strong overall conservation of synteny between both strains and a detailed analysis revealed the absence of large genomic regions from the chromosome of the probiotic strain, indicating gene loss. Genes absent from the Symbioflor 1 strain included those encoding the enterococcal cytolysin, enterococcal surface protein, and gelatinase (coccolysin) as well as hyaluronidase and the peptide antibiotic AS-48. This data was confirmed using PCR primers specific for the respective genes. However, other enterococcal determinants such as aggregation substance, collagen adhesion protein, the ability to resist oxygen anions as well as capsule formation were detected. The presence of these traits may be advantageous for the strain Symbioflor 1 since they potentially enable colonization and proliferation of the bacterium on mucosal surfaces thereby conferring on it probiotic traits.     

Probiotic intervention influences the salivary levels of Matrix Metalloproteinase (MMP)-9 and Tissue Inhibitor of metalloproteinases (TIMP)-1 in healthy adults

ObjectiveTo study the effect of orally administered Bifidobacterium animalis subsp. lactis BB-12 and Lactobacillus rhamnosus GG on the salivary levels of Matrix Metalloproteinases (MMP)-8, MMP-9 and of Tissue Inhibitor of Metalloproteinases (TIMP)-1 in healthy adults. Furthermore, the correlations between MMP-8, MMP-9 and TIMP-1 and plaque and gingival indices, salivary mutans streptococci and lactobacilli counts, and stimulated saliva secretion rate were analysed.DesignThe salivary samples originated from a randomized controlled trial where healthy student volunteers consumed probiotic or placebo lozenges twice a day for four weeks. The saliva samples were collected and clinical parameters measured at the baseline and at the end of the original study. For this study, the salivary levels of MMP-8, MMP-9 and TIMP-1 were analysed with immunofluorometric assay (IFMA) and enzyme-linked immunosorbent assay (ELISA).ResultsIn the probiotic group (n = 29), salivary MMP-9 levels increased (p < 0.01) and TIMP-1 levels decreased (p < 0.01) significantly during the intervention. Furthermore, MMP-9/TIMP-1 ratio differed significantly from the baseline level (p < 0.01). These changes were not observed in the control group (n = 31). In the whole data, salivary MMP-9 and gingival index correlated (r = 0.260, p < 0.05 at baseline and r = 0.354, p < 0.01 at the end of the study). Intergroup differences or correlations with other clinical parameters were not found. Probiotic consumption did not affect the saliva flow rate.ConclusionsIncreased MMP-9 and decreased TIMP-1 levels in saliva may indicate that probiotics have immunomodulatory effects in the oral cavity. Furthermore, increased salivary MMP-9 levels may be an indication of the defensive potential of matrix metalloproteinases.     

Novel nitric oxide producing probiotic wound healing patch: preparation and in vivo analysis in a New Zealand white rabbit model of ischaemic and infected wounds

The treatment of chronic wounds poses a significant challenge for clinicians and patients alike. Here we report design and preclinical efficacy of a novel nitric oxide gas (gNO)-producing probiotic patch for wound healing. Specifically, a wound healing patch using lactic acid bacteria in an adhesive gas permeable membrane has been designed and investigated for treating ischaemic and infected full-thickness dermal wounds in a New Zealand white rabbit model for ischaemic wound healing. Kaplan-Meier survival curves showed increased wound closure with gNO-producing patch-treated wounds over 21 days of therapy (log-rank P = 0·0225 and Wilcoxon P = 0·0113). Cox proportional hazard regression showed that gNO-producing patch-treated wounds were 2·52 times more likely to close compared with control patches (hazard P = 0·0375, score P = 0·032 and likelihood ratio P = 0·0355), and histological analysis showed improved wound healing in gNO-producing patch-treated animals. This study may provide an effective, safe and less costly alternative for treating chronic wounds.     

益生菌对炎性肠病小鼠肠屏障功能的影响

目的 研究益生菌植物乳杆菌(LP)对炎症状态下肠屏障的修复机理.方法 以白介素-10基因敲除(IL-10-/-)小鼠为炎性肠病模型,采用简单随机法(随机表)将空白对照(WT)小鼠和IL-10-/-小鼠分成4组:WT组、WT+ LP组、IL-10-/-组和IL-10-/-+ LP组,每组10只.分别灌饲Ringer液或LP溶液,持续4周.每周记录小鼠肠炎的临床表现,实验结束后收集小鼠结肠组织,进行病理评分和形态观察,ELISA法检测结肠组织促炎细胞因子肿瘤坏死因子-α(TNF-α)和干扰素-γ(IFN-γ)浓度,利用Ussing Chamber技术对小鼠结肠通透性及电生理变化进行分析,并用Western blot和免疫荧光分析法对结肠上皮细胞紧密连接蛋白进行定量和定位研究.结果 与WT组相比,IL-10-/-组小鼠腹泻、直肠脱垂和体重丧失较明显(P＜0.01);TNF-α和IFN-γ浓度明显升高(P＜0.01);病理表现为大量炎性细胞浸润,偶见透壁性溃疡和隐窝脓肿形成;超微电镜提示紧密连接结构破坏;紧密连接蛋白( ZO-1、occludin、claudin-1)表达明显降低(P＜0.01)且伴有异常分布;结肠上皮细胞甘露醇通透性升高(P＜0.001),跨膜电阻值降低(P＜0.001).LP干预4周后,与IL-10-/-组相比,LP能显著改善肠道炎症的临床和病理表现,阻止紧密连接超微结构破坏,促进紧密连接蛋白的表达(P＜0.01),降低结肠上皮细胞甘露醇通透性(P＜0.001),升高跨膜电阻值(P＜0.001),降低了TNF-α和IFN-γ的浓度(P＜0.01),减轻了肠道炎症.结论 LP能通过促进肠上皮细胞间紧密连接蛋白的表达修复受损肠屏障功能,从而减轻肠道炎症.     

Modification in the diet can induce beneficial effects against breast cancer

The population tends to consume foods that in addition to their nutritional values can offer some benefits to their health. There are many epidemiological evidences and research studies in animal models suggesting that diet plays an important role in breast cancer prevention or progression. This review summarized some of the relevant researches about nutrition and cancer during the last years, especially in breast cancer. The analysis of probiotics and fermented products containing lactic acid bacteria in cancer prevention and/or treatment was especially discussed. It was observed that a balance of fatty acids similar to those of traditional Mediterranean diet, the consumption of fruits and vegetables, dietary fiber intake, vitamin supplementation are, along with the intake of probiotic products, the most extensively studied by the negative association to breast cancer risk. The consumption of probiotics and fermented products containing lactic acid bacteria was associated to reduce breast cancer risk in some epidemiological studies. The use of animal models showed the modulation of the host’s immune response as one of the important effects associated to the benefices observed with most probiotics. However; future assays in human are very important before the medical community can accept the addition of probiotic or fermented milks containing lactic acid bacteria as supplements for cancer patients.     

Probiotic and synbiotic supplementation could improve metabolic syndrome in prediabetic adults: A randomized controlled trial

AimsModulation of the gastrointestinal microbiome is suggested to contribute to the progression of metabolic syndrome associated diseases. This study was designed to assess the effects of probiotics and synbiotics on metabolic syndrome in individuals with prediabetes.Methods120 adults with prediabetes were enrolled in a double-blind, placebo-controlled randomized parallel-group clinical trial. Participants were randomized to a multi-species probiotic or inulin-based synbiotic or placebo. Blood samples and anthropometric measures were collected at baseline, 12 and 24 weeks after treatment. The primary outcome measures were the changes between groups in metabolic syndrome and its components' prevalence.ResultsA significant trend for a reduction in the prevalence of hyperglycemia in probiotic and synbiotic groups (p = 0.01 and 0.005 respectively), and hypertension in probiotic group (p = 0.04) was found. The decreases in metabolic syndrome prevalence were significant after taking probiotic and synbiotic supplementation as compared with placebo (p = 0.02). Also, the prevalence of low HDL-cholesterol level was decreased during the study in the probiotic group compared with placebo (p = 0.02).ConclusionsThe potential benefits of using probiotic and synbiotic for metabolic syndrome management in prediabetes have been supported by the results in the current study which might provide an important strategy to combat metabolic syndrome-associated diseases.     

Lactobacillus delbrueckii UFV-H2b20 increases IFN-γ production and CD39+CD73+ Treg cell numbers in lungs,and protects mice against experimental allergic asthma

Asthma is a disorder characterized by airflow obstruction, inflammation, declining airway function, bronchial hyperresponsiveness and tissue remodelling. Probiotics are defined as “live microorganisms that, when administered in adequate amounts, confer a health benefit on the host”. The use of probiotics is becoming increasingly studied and recent evidence has suggested that it may provide therapeutic benefits in asthma and other diseases. Lactobacillus delbrueckii UFV-H2b20 fulfils all the requirements to be classified as probiotic. Previous studies have already shown the ability of L. delbrueckii UFV-H2b20 to stimulate the immune system. Our objective was to evaluate the protective effects of L. delbrueckii UFV-H2b20 in experimental allergic asthma. We used a murine model of ovalbumin-induced allergic airway inflammation to mimic allergic asthma. Oral treatment with L. delbrueckii UFV-H2b20 improves respiratory parameters and inhibits the inflammatory response in the lungs by decreasing the numbers of inflammatory monocytes, eosinophils and alveolar macrophages, as well as IgE levels. Treatment increased the IFN-γ/IL-4 cytokine ratio. Levels of IL-10 in the lungs were also increased in treated animals. Our results also showed that the probiotic administration increases the number of CD39⁺CD73⁺ T regulatory lymphocytes in the lung, suggesting a role for purinergic signals in the regulation of inflammation promoted by the treatment. Understanding the mechanisms of modulation of the immune system by probiotics could allow the development of probiotic preparations that are safe and have a direct action. Our results suggest that oral administration of L. delbrueckii UFV-H2b20 could be helpful to treat chronic inflammatory airway diseases, such as asthma.     

益生菌辅助治疗变应性鼻炎疗效的Meta分析

目的通过Meta分析对益生菌辅助治疗变应性鼻炎（AR）的临床疗效进行评价。方法系统检索知网、万方、PubMed数据库，检索发表自2010年1月—2019年12月使用益生菌治疗AR的文献，按照纳入及排除标准筛选并提取数据资料、行质量评价。采用RevMan 5.2软件进行Meta分析。结果最终纳入随机对照试验13例，共1 268例患者，其中常规治疗+益生菌组631例，常规治疗+安慰剂或仅常规治疗组637例。Meta分析结果显示：常规治疗+益生菌组治疗后鼻部症状评分较常规治疗+安慰剂或仅常规治疗组降低，差异具有统计学意义（MD=-1.84，95％CI=［-2.43，-1.24］，P<0.05）。两组治疗AR有效率存在差异，但差异无统计学意义（RR=1.36，95％CI=［1.00，1.85］，P=0.05）。结论常规治疗+益生菌组与常规治疗+安慰剂或仅常规治疗组比，治疗后AR鼻部症状评分下降；两组治疗总有效率差异无统计学意义。     

Effect of a fermented milk containing Bifidobacterium lactis DN-173010 on Chinese constipated women

AIM： To investigate the effect of a fermented milk containing Bifidobacterium lactis DN-173010 and yogurt strains （BIO） on adult women with constipation in Beijing. METHODS： A total of 135 adult females with constipation were randomly allocated to consume for 2 wk either 100 g of the test fermented milk or 100 g of an acidified milk containing non-living bacteria （control）. Stool frequency, defecation condition scores, stool consistency and food intake were recorded at baseline and after 1 and 2 wk in an intention-totreat population of 126 subjects. In parallel, safety evaluation parameters were performed. RESULTS： At baseline, no differences were found between groups. Following consumption of test product, stool frequency was significantly increased after 1 wk （3.5±1.5 vs 2.4 ± 0.6, P 〈 0.01） and 2 wk （4.1 ± 1.7 vs 2.4 ± 0.6, P 〈 0.01）, vs baseline. Similarly, after 1 and 2 wk, of test product consumption, defecation condition （1.1 ± 0.9 vs 1.9 ±1.2, P 〈 0.01 and 0.8 ± 1.0 vs 1.9 ± 1.2, P 〈 0.01, respectively） and stool consistency （1.0 ± 0.8 vs 1.5 ±1.1, P 〈 0.01 and 0.6±0.8 vs 1.5 ± 1.1,P 〈 0.01, respectively） were significantly improved. Compared with the control group, stool frequency was also significantly increased （3.5 ± 1.5 vs 2.5 ± 0.9, P 〈 0.01 and 4.1 ± 1.7 vs 2.6 ± 1.0, P 〈 0.01, respectively）, and defecation condition （1.1 ± 0.9 vs 1.6 ± 1.1, P 〈 0.01 and 0.8 ± 1.0 vs 1.6 ± 1.1, P 〈 0.01, respectively） and stool consistency （1.0 ± 0.8 vs 1.4 ± 1.0, P 〈 0.05 and 0.6 ± 0.8 vs 1.3 ± 1.0, P 〈 0.01, respectively） significantly decreased after 1 and 2 wk of product consumption. During the same period, food intake did not change between the two groups, and safety parameters of the subjects were within normal ranges. CONCLUSION： This study suggests a beneficial effect of a fermented milk containing B. lactis DN-173010 on stool frequency, defecation condition and stool consistency in adult women with constipation cons