Characterization Of Probiotic Strains Research Articles

PCR Based Technique for Identification of Bile Salt Hydrolase Positive Lactobacilli

In the burgeoning landscape of probiotic research, the intricate interplay between the gut microbiota and host health has underscored the significance of specific enzymatic activities, notably bile salt hydrolase (BSH) produced by Lactobacilli. Harnessing the potential health benefits associated with BSH activity necessitates a meticulous identification strategy. In response, this study introduces a sophisticated PCR-based technique tailored for the rapid and precise discrimination of lactobacilli strains boasting BSH enzymatic prowess. This PCR-based approach offers a valuable tool for researchers and industry professionals involved in the selection and characterization of probiotic strains with bile salt hydrolase activity. Its speed, accuracy, and adaptability make it a promising method for large-scale screenings and applications in diverse fields, ranging from food science to the development of probiotic supplements aimed at enhancing human health through the modulation of bile acid metabolism. robiotic supplementation, where the modulation of bile acid metabolism holds promise for promoting human health and well-being.

Isolation and Characterization of Probiotic Strains from Garcinia mangostana (Mangosteen) for Nutraceutical Applications

Isolation and Characterization of Probiotic Strains from Garcinia mangostana (Mangosteen) for Nutraceutical Applications

Binding activity to intestinal cells and transient colonization in mice of two Lactobacillus paracasei subsp. paracasei strains with high aggregation potential.

Surface properties like hydrophobicity, aggregation ability, adhesion to mucosal surfaces and epithelial cells and transit time are key features for the characterization of probiotic strains. In this study, we used two Lactobacillus paracasei subsp. paracasei strains (BGNJ1-64 and BGSJ2-8) strains which were previously described with very strong aggregation capacity. The aggregation promoting factor (AggLb) expressed in these strains showed high level of binding to collagen and fibronectin, components of extracellular matrix. The working hypothesis was that strains able to aggregate have an advantage to resist in intestinal tract. So, we assessed whether these strains and their derivatives (without aggLb gene) are able to bind or not to intestinal components and we compared the transit time of each strains in mice. In that purpose parental strains (BGNJ1-64 and BGSJ2-8) and their aggregation negative derivatives (BGNJ1-641 and BGSJ2-83) were marked with double antibiotic resistance in order to be tracked in in vivo experiments in mice. Comparative analysis of binding ability of WT and aggregation negative strains to different human intestinal cell lines and mucin revealed no significant difference among them, excluding involvement of AggLb in interaction with surface of intestinal cells and mucin. In vivo experiments showed that surviving and transit time of marked strains in mice did not drastically depend on the presence of the AggLb aggregation factor.

Recent Advances in Screening of Anti-Campylobacter Activity in Probiotics for Use in Poultry.

Campylobacteriosis is the most common cause of bacterial gastroenteritis worldwide. Campylobacter species involved in this infection usually include the thermotolerant species Campylobacter jejuni. The major reservoir for C. jejuni leading to human infections is commercial broiler chickens. Poultry flocks are frequently colonized by C. jejuni without any apparent symptoms. Risk assessment analyses have identified the handling and consumption of poultry meat as one of the most important sources of human campylobacteriosis, so elimination of Campylobacter in the poultry reservoir is a crucial step in the control of this foodborne infection. To date, the use of probiotics has demonstrated promising results to reduce Campylobacter colonization. This review provides recent insights into methods used for probiotic screening to reduce the prevalence and colonization of Campylobacter at the farm level. Different eukaryotic epithelial cell lines are employed to screen probiotics with an anti-Campylobacter activity and yield useful information about the inhibition mechanism involved. These in vitro virulence models involve only human intestinal or cervical cell lines whereas the use of avian cell lines could be a preliminary step to investigate mechanisms of C. jejuni colonization in poultry in the presence of probiotics. In addition, in vivo trials to evaluate the effect of probiotics on Campylobacter colonization are conducted, taking into account the complexity introduced by the host, the feed, and the microbiota. However, the heterogeneity of the protocols used and the short time duration of the experiments lead to results that are difficult to compare and draw conclusions at the slaughter-age of broilers. Nevertheless, the combined approach using complementary in vitro and in vivo tools (cell cultures and animal experiments) leads to a better characterization of probiotic strains and could be employed to assess reduced Campylobacter spp. colonization in chickens if some parameters are optimized.

Diet therapy for inflammatory bowel diseases: The established and the new.

Although patients with inflammatory bowel diseases (IBD) have a strong interest in dietary modifications as part of their therapeutic management, dietary advice plays only a minor part in published guidelines. The scientific literature shows that dietary factors might influence the risk of developing IBD, that dysbiosis induced by nutrition contributes to the pathogenesis of IBD, and that diet may serve as a symptomatic treatment for irritable bowel syndrome-like symptoms in IBD. The role of nutrition in IBD is underscored by the effect of various dietary therapies. In paediatric patients with Crohn's disease (CD) enteral nutrition (EN) reaches remission rates similar to steroids. In adult patients, however, EN is inferior to corticosteroids. EN is not effective in ulcerative colitis (UC). Total parenteral nutrition in IBD is not superior to steroids or EN. The use of specific probiotics in patients with IBD can be recommended only in special clinical situations. There is no evidence for efficacy of probiotics in CD. By contrast, studies in UC have shown a beneficial effect in selected patients. For patients with pouchitis, antibiotic treatment followed by probiotics, like VSL#3 or Lactobacillus GG, is effective. When probiotics are used, the risk of bacterial translocation and subsequent bacteremia has to be considered. More understanding of the normal intestinal microflora, and better characterization of probiotic strains at the phenotypic and genomic levels is needed as well as clarification of the mechanisms of action in different clinical settings. A FODMAP reduced diet may improve symptoms in IBD.

Molecular identification of probiotics lactobacillus strain isolates by amplified ribosomal DNA restriction analysis (ARDRA)

In recent years interest in the probiotic lactobacilli has been stimulated by the use of these bacteria in products that are claimed to confer health benefits on the consumer. The objective of this study is to characterize probiotic Lactobacillus sp isolated from fermented millet drink , fresh milk and raw cow milk. All isolates are focusing on their screened for their probiotic potential activities, including Biochemical characterization and antagonistic activity . A total of seven colonies of lactobacilli isolated from twenty samples of fermented millet drink ,fresh and raw cow milk were obtained based on their colonial/morphological and biochemical characteristics. The Lactobacillus isolates obtained from fermented millet drinks are more effective than isolates from fresh milk and Cow milk as regards their antagonism or inhibition. Microbial identification has been drastically improved both quality and effectiveness wise by molecular methods applications. Molecular characterization of probiotic strains only in phenotypic and physiological characteristics is often with low level of discrimination, probably due to their co-evolution in the same ecological niches. Thus, the nucleotide base techniques provide an accurate basis for phylogenetic analysis and identification. The other specific aim of the study is to analyze a probiotic Lactobacillus sp isolates . The seven selected isolates were identify to species level as L. plantarum, L. lactis , L. acidophilu, and L. helveticus using API 50CH Kits. Amplified Ribosomal DNA Restriction Analysis (ARDRA) using Alu I (AGCT), Mbo I (GATC) and Msp I (CCGG) restriction enzymes and 16S rDNA gene sequencing was identified Lactobacillus isolates under study. ARDRA screening revealed unique patterns among seven isolates, with the same pattern for some the isolates. Gene fragments of 16S rDNA of strains representing specific patterns that needed to be sequence to confirm the identification of these species. These results confirmed that ARDRA is a good tool for identification and discrimination of bacterial species isolated from complex ecosystem and between closely related groups.

Characterization of probiotic strains: An application as feed additives in poultry against Campylobacter jejuni

Campylobacteriosis is at present the most frequent zoonosis in humans and the main source is poultry meat contaminated by Campylobacter jejuni. An alternative and effective approach to antibiotic administration to livestock to reduce bacterial contamination is the use of probiotics, which can help to improve the natural defence of animals against pathogenic bacteria. In this study 55 lactic acid bacteria and bifidobacteria were screened for desirable properties for their application as probiotics against Campylobacter in poultry. All bacteria were examined for their antimicrobial activity against three C. jejuni strains. Strains exhibiting the highest anti- Campylobacter activity were examined for their survival in the gastro intestinal tract (low pH and presence of bile salts) and food/feed processing conditions (high temperature, high NaCl concentration and starvation) and basic safety aspects such as antibiotic susceptibility and hemolytic activity were studied. On the basis of these activities, two strains, namely Lactobacillus plantarum PCS 20 and Bifidobacterium longum PCB 133, were chosen for an in vivo trial in poultry. They were separately administered to healthy chickens in order to evaluate their capability of colonizing the GI tract of poultry and to estimate their effect on C. jejuni population. The results evidenced that L. plantarum PCS 20 was not present in poultry feces at detectable concentration, whereas B. longum PCB 133 significantly increased after two weeks of daily administration and its amount was still high after a wash-out period of 6 days. In the same period, C. jejuni concentration in poultry feces was significantly reduced in chickens administered with B. longum PCB 133. Therefore, B. longum PCB 133, possessing interesting probiotic properties and a marked anti- Campylobacter activity both in vitro and in vivo, is an excellent candidate for being employed as additives to feed for poultry for the reduction of food-borne campylobacteriosis in humans.