Determining the probiotic potential of cholesterol-reducing Lactobacillus and Weissella strains isolated from gherkins (fermented cucumber) and south Indian fermented koozh

Tracing probiotic producing bacterial species from gut of buffalo (Bubalus bubalis), South-East-Asia

Abstract Due to extensive application of antibiotics as growth promoters in animal feed, antimicrobial resistance has been increased. To overcome this challenge, rumen microbiologists search for new probiotics to improve the rate of livestock production. The present study was aimed to isolate and evaluate breed-specific lactic acid bacteria (LAB) as potential animal probiotics. The current study was conducted during 10 months from July 2020 to April 2021, in which a total of n=12 strains were isolated from different samples including milk, rumen, and feces of Nilli Ravi Buffaloes. These isolates were evaluated for their antimicrobial potential against common animal pathogens (Bacillus spp., E. coli, Staphylococcus aureus, Salmonella spp., Listeria spp.). All the isolates were identified using 16S rRNA gene sequencing and the phylogenetic analyses inferred that these strains showed close relations to the species of various genera; Enterococcus lactis, Pediococcus pentosaceus, Bacillus subtilis Weissella cibaria, Weissella soli, Bacillus tequilensis, Weissella bombi, Bacillus licheniformis, Lactococcus lactis, Bacillus megaterium, Lactobacillus ruminis, and Lactococcus lactis. NMCC-Ru2 has exhibited the enormous potential of antimicrobial activity, 28 mm, for Salmonella typhimurium;23 mm for Listeria monocytogenes 21 mm for E.coil. Highest resistance was seen in NMCC-Ru2 agasint test antbiotic, like 25.5 mm for Tetracycline. Overall results revesl that the probiotic profile of isolates was achieved using standard criteria, particularly with animal probiotic properties

The Weissella and Periweissella genera: up-to-date taxonomy, ecology, safety, biotechnological, and probiotic potential

Bacteria belonging to the genera Weissella and Periweissella are lactic acid bacteria, which emerged in the last decades for their probiotic and biotechnological potential. In 2015, an article reviewing the scientific literature till that date on the taxonomy, ecology, and biotechnological potential of the Weissella genus was published. Since then, the number of studies on this genus has increased enormously, several novel species have been discovered, the taxonomy of the genus underwent changes and new insights into the safety, and biotechnological and probiotic potential of weissellas and periweissellas could be gained. Here, we provide an updated overview (from 2015 until today) of the taxonomy, ecology, safety, biotechnological, and probiotic potential of these lactic acid bacteria.

Safety aspects, probiotic potentials of yeast and lactobacillus isolated from fermented foods in North-Eastern India, and its anti-inflammatory activity

Lactobacillus and yeast obtained from fermented foods in North-East India were tested for safety and probiotic properties. All the lactobacilli and yeast tested negative for the catalase, indole, urease, phenylalanine, hemolysis, gelatin hydrolysis, and biogenic amine production tests, indicating that they are safe to use as probiotics in food supplements. Lactiplantibacillus plantarum KGL3A (accession no. MG722814) was capable of resisting the replicated gastric fluid (pH 2) till 2 h of exposure, whereas both KGL3A and Lacticaseibacillus rhamnosus K4E (accession no. KX950834.1) strains were able to resist pH 3 till 2 h of exposure with a reduction in overall viable cell count from 7.48 log CFU/mL to 1.09 log CFU/mL and 7.77 log CFU/mL to 0.83 log CFU/mL, respectively. In vitro gastric juice simulation conditions were tolerated by the yeast Saccharomyces cerevisiae WBS2A. The cell surface hydrophobicity (CSH) towards hydrocarbons (n-hexadecane) was seen highest in L. plantarum KGL3A (77.16± 0.84%) and Limosilactobacillus fermentum KGL4 accession no. MF951099 (72.60 ± 2.33%). The percentage auto-aggregation ranged from 8.70 to 25.53 after 2 h, which significantly increased to 10.50 to 26.94 during the fifth hour for cultures. Also, a higher percentage of co-aggregation was found for the culture L. rhamnosus K4E with S. typhi (34.18 ± 0.03%), E. coli (32.97 ± 0.02 %) and S. aureus (26.33 ± 0.06 %) and for the yeast S. cerevisiae WBS2A, a higher percentage of co-aggregation was found with Listeria monocytogenes (25.77 ± 0.22%). The antioxidant activity and proteolytic activity were found to be higher for Lactobacillus helveticus K14 and L. rhamnosus K4E. The proportion of decreased cholesterol was noticeably higher in KGL4 (29.65 ± 4.30%). β glucosidase activity was significantly higher in the L. fermentum KGL4 strain (0.359 ± 0.002), and α galactosidase activity was significantly higher in the L. rhamnosus K4E strain (0.415 ± 0.016). MTT assays suggested that KGL4 and WBS2A at a lower dose did not exhibit cytotoxicity.

Weissella confusa N17 Derived from Loach (Misgurnus anguillicaudatus) Exhibits Promising for Further Applications in Loach Aquaculture

The application of probiotics, in aquaculture, is becoming increasingly widespread and have had positive application effects. However, reports of loach-derived probiotics are quite limited. In this study, two representative strains of lactic acid bacteria with excellent traits, namely, Weissella confusa N17 and Lactobacillus saniviri N19, were screened from the intestine of healthy loaches. W. confusa N17 and L. saniviri N19 could inhibit different common various pathogenic bacteria, especially Aeromonas spp., and were sensitive to the most common antibiotics. The survival rate of the two strains exceeded 50% after 4 h of incubation in 10% loach bile. Moreover, the two strains showed significant tolerance to trypsin. Their autoaggregation capacity and hydrophobicity were greater than 30%. In addition, the aggregation ability of both strains was higher than 30% for both A. veronii TH0426 and A. hydrophila TPS. The two strains had a high biofilm-forming ability and strong adhesion to epithelioma papulosum cyprini (EPC) cells. Scanning electron microscopy results showed that the culture supernatants of the two strains had a significantly destructive effect on A. veronii TH0426 and A. hydrophila TPS. Overall, the traits of W. confusa N17 were better than those of L. saniviri N19. Genome sequencing and analysis demonstrated a lack of virulence factor-related or drug resistance-related genes in genome N17. The diet supplemented with the W. confusa N17 strain significantly improved the resistance of loaches to A. veronii infection, and the protection rate reached 57.1%. Therefore, W. confusa N17 exhibits promising for further applications in loach aquaculture.

Exploring the Cholesterol-Modifying Abilities of Lactobacilli Cells in Digestive Models and Dairy Products

This study aimed to investigate the ability of lactic acid bacteria to remove cholesterol in simulated gastric and intestinal fluids. The findings showed that the amount of cholesterol removed was dependent on the biomass, viability, and bacterial strain. Some cholesterol binding was stable and not released during gastrointestinal transit. The presence of cholesterol affected the fatty acid profile of bacterial cells, potentially influencing their metabolism and functioning. However, adding cholesterol did not significantly impact the survival of lactic acid bacteria during gastrointestinal transit. Storage time, passage, and bacterial culture type did not show significant effects on cholesterol content in fermented dairy products. Variations in cell survival were observed among lactic acid bacteria strains in simulated gastric and intestinal fluids, depending on the environment. Higher milk protein content was found to be more protective for bacterial cells during gastrointestinal transit than fat content. Future research should aim to better understand the impact of cholesterol on lactic acid bacteria metabolism and identify potential health benefits.

In vitro characterization of lactic acid bacterial strains isolated from fermented foods with anti-inflammatory and dipeptidyl peptidase-IV inhibition potential

Probiotics are known to stimulate, modulate, and regulate host immune response by regulating specific sets of genes and improve glucose homeostasis through regulating dipeptidyl peptidase (DPP-IV) activity, but the mechanism behind their protective role is not clearly understood. Therefore, the present study was designed to isolate indigenous lactic acid bacterial (LAB) strains from different fermented food samples, vegetables, and human infant feces exhibiting anti-inflammatory, antioxidant, and DPP-IV inhibitory activity. A total of thirty-six Gram-positive, catalase-negative, and rod-shaped bacteria were isolated and screened for their anti-inflammatory activity using lipopolysaccharide (LPS)-induced inflammation on the murine (RAW264.7) macrophages. Among all, sixteen strains exhibited more than 90% reduction in nitric oxide (NO) production by the LPS-treated RAW264.7 cells. Prioritized strains were characterized for their probiotic attributes as per the DBT-ICMR guidelines and showed desirable probiotic attributes in a species and strain-dependent manner. Accordingly, Lacticaseibacillus rhamnosus LAB3, Levilactobacillus brevis LAB20, Lactiplantibacillus plantarum LAB31, Pediococcus acidilactici LAB8, and Lactiplantibacillus plantarum LAB39 were prioritized. Furthermore, these strains when co-supplemented with LPS and treated on RAW264.7 cells inhibited the mitogen-activated protein kinases (MAPKs), i.e., p38 MAPK, ERK1/2, and SAPK/JNK, cyclooxygenase-2 (COX-2), relative to the LPS-alone-treated macrophages. LAB31 and LAB39 also showed 64 and 95% of DPP-IV inhibitory activity relative to the Lacticaseibacillus rhamnosus GG ATCC 53103, which was used as a reference strain in all the studies. Five prioritized strains ameliorated the LPS-induced inflammation by downregulating the JNK/MAPK pathway and could be employed as an alternative bio-therapeutic strategy in mitigating gut-associated inflammatory conditions. The potential mechanism of action of prioritized LAB strains in preventing the LPS-induced inflammation in RAW 264.7 macrophage cells.

Freeze dried probiotic carrot juice powder for better storage stability of probiotic

Probiotic strains isolated from Gundruk- a traditional Indian fermented food-and fermented carrot juice, were evaluated for their probiotic properties and analyzed probiotic properties such as lactic acid production, NaCl tolerance, and acid tolerance for all the isolated strains. Most isolated strains were susceptible to antibiotics, and cell-free extracts showed potential antioxidant activity and observed antagonistic properties against foodborne pathogens such as Salmonella typhi ATCC 6539, Escherichia coli ATCC 25922, Shigella ATCC 12022, and Staphylococcus ATCC 29213. The isolate Enterococcus faecalis(K13), was incorporated in carrot juice and microencapsulated by freeze-drying and spray drying. Gum Arabic and maltodextrin were used as coating materials. The physicochemical properties, such as bulk density, moisture content, water activity and color of the powders, and the survivability of probiotic bacteria, were studied on storage. The freeze-dried probiotic formulation is suggested over spray-dried formulation for further use, since it had good storage stability up to one month (6-7 Log CFU/g).

Effect of synbiotic bread containing lactic acid on blood lipids and apolipoproteins in patients with type 2 diabetes: A randomized controlled trial

Recently, the use of synbiotics for managing various diseases has dramatically increased. Synbiotics have been shown to be a good approach to influence the composition of the gut microbiota with positive health effects. Management of type 2 diabetes mellitus (T2DM) complications is one of the reasons for the ingestion of synbiotics and so the aim of the current study was to determine the effects of synbiotic bread intake on markers of lipid profile in T2DM patients. One hundred T2DM patients (age between 20 and 60 years) were randomly assigned to four groups to consume different types of synbiotic bread, three times/day, for 8 weeks: "synbiotic + lactic acid" (n = 25; IV), "synbiotic" (n = 25; III), "lactic acid brad" (n = 25; II), or "control" (n = 25; I). The measured outcomes included anthropometric characteristics, glycemic control parameters, blood lipids, and apolipoproteins. The consumption of "synbiotic + lactic acid bread" (group IV) and "lactic acid bread" (group II) led to a significant decrease in total cholesterol (TC) and glycated hemoglobin (HbA1c) compared to the "control bread." The HbA1c levels were also significantly lower when compared to group II. Additionally, apolipoprotein A (Apo A1) levels were significantly decreased in group IV, compared to control and other groups (post hoc analysis). No significant differences between groups were observed for triglyceride (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), and apolipoprotein B100 (Apo B100) levels. The observed results show that the synbiotic bread (with or without lactic acid) promoted a decrease in total cholesterol (TC) and Apo A1 in diabetic patients when consumed daily for 8 weeks.

Assessment of the safety and probiotic properties of Roseburia intestinalis: A potential “Next Generation Probiotic”

Roseburia intestinalis is an anaerobic bacterium that produces butyric acid and belongs to the phylum Firmicutes. There is increasing evidence that this bacterium has positive effects on several diseases, including inflammatory bowel disease, atherosclerosis, alcoholic fatty liver, colorectal cancer, and metabolic syndrome, making it a potential “Next Generation Probiotic.” We investigated the genomic characteristics, probiotic properties, cytotoxicity, oral toxicity, colonization characteristics of the bacterium, and its effect on the gut microbiota. The genome contains few genes encoding virulence factors, three clustered regularly interspaced short palindromic repeat (CRISPR) sequences, two Cas genes, no toxic biogenic amine synthesis genes, and several essential amino acid and vitamin synthesis genes. Seven prophages and 41 genomic islands were predicted. In addition to a bacteriocin (Zoocin A), the bacterium encodes four metabolic gene clusters that synthesize short-chain fatty acids and 222 carbohydrate-active enzyme modules. This bacterium is sensitive to antibiotics specified by the European Food Safety Authority, does not exhibit hemolytic or gelatinase activity, and exhibits some acid resistance. R. intestinalis adheres to intestinal epithelial cells and inhibits the invasion of certain pathogens. In vitro experiments showed that the bacterium was not cytotoxic. R. intestinalis did not affect the diversity or abundance of the gut flora. Using the fluorescent labelling method, we discovered that R. intestinalis colonizes the cecum and mucus of the colon. An oral toxicity study did not reveal any obvious adverse effects. The lethal dose (LD)50 of R. intestinalis exceeded 1.9 × 10⁹ colony forming units (CFU)/kg, whereas the no observed adverse effect level (NOAEL) derived from this study was 1.32 × 10⁹ CFU/kg/day for 28 days. The current research shows that, R. intestinalis is a suitable next-generation probiotic considering its probiotic properties and safety.

Isolation and Characterization of a Cholesterol-Lowering Bacteria from Bubalus bubalis Raw Milk

Probiotics retrieved from animal sources have substantial health benefits for both humans and animals. The present study was designed to identify lactic acid bacteria (LAB) isolated from domestic water buffalo milk (Bubalus bubalis) and to evaluate their potential as target-based probiotics. Forty-six LAB strains were isolated and, among them, five strains (NMCC-M2, NMCC-M4, NMCC-M5, NMCC-M6, and NMCC-M7) were regarded as possible probiotics on the basis of their phenotypic and biochemical properties. These isolates were molecularly identified as Weissella confusa (NMCC-M2), Leuconostoc pseudo-mesenteroides (NMCC-M4), Lactococcus lactis Subsp. hordniae (NMCC-M5), Enterococcus faecium NMCC-M6, and Enterococcus lactis NMCC-M7. The tested bacterial strains showed significant antimicrobial activity, susceptibility to antibiotics, acid and bile tolerance, sugar fermentation, enzymatic potential, and nonhemolytic characteristics. Interestingly, NMCC-M2 displayed the best probiotic features including survival at pH 3 and 0.5% (w/v) bile salts, complete susceptibility to the tested antibiotics, high enzymatic potential, and in vitro cholesterol reduction (48.0 µg/mL for NMCC-M2) with 0.3% bile salt supplementation. Therefore, the isolated strain NMCC-M2 could be considered as a potential target-based probiotic in cholesterol-lowering fermented food products.

Bacterial Communities in Lanna Phak-Gard-Dong (Pickled Mustard Green) from Three Different Ethnolinguistic Groups in Northern Thailand

The Lanna region, the main part of northern Thailand, is a place of ethnic diversity. In this study, we investigated phak-gard-dong (PGD), or pickled mustard green (Brassica juncea L. Czern.), for its beneficial bacteria content and to analyse the variations in bacterial compositions among the PGD of three different ethnolinguistic groups, the Karen, Lawa, and Shan. DNA was extracted from the PGD pickled brine, and 16S rRNA gene Illumina sequencing was performed. Metagenomic data were analysed and the results demonstrated that the dominant bacterial species were Weissella (54.2%, 65.0%, and 10.0%) and Lactobacillus (17.5%, 5.6%, and 79.1%) in the PGD of the Karen, Lawa, and Shan, respectively. Pediococcus was found only in the PGD of the Karen and Shan. Bacterial communities in PGD of the Lawa were distinctive from the other ethnic groups, both in the alpha and beta diversity, as well as the predicted functions of the bacterial communities. In addition, overall network analysis results were correlated to bacterial proportions in every ethnic PGD. We suggest that all ethnic PGDs have the potential to be a good source of beneficial bacteria, warranting its conservation and further development into health food products.

Dynamics and removal mechanisms of antibiotic and antibiotic resistance genes during the fermentation process of spectinomycin mycelial dregs: An integrated meta-omics study

Antibiotic mycelial dregs (AMDs) have been listed as industrial hazardous wastes. With the aim of reducing the environmental risk, the integrated-omics and qPCR approaches were used to reveal the dynamics and removal mechanisms of antibiotic and antibiotic resistance genes (ARGs) during the fermentation of different spectinomycin mycelial dregs (SMDs). The results showed that the removal efficiency of antibiotic in the fermentation of high moisture SMDs reached up to 98%. The high abundance of aadA1 gene encoded by Streptomyces, Lactobacillus, and Pseudomonas was associated with the efficient degradation of spectinomycin, and the inactivating enzymes secreted by degradative bacteria were identified. Furthermore, the dominant microbiota was impacted by moisture content significantly under high temperature environments. In the fermentation of low moisture SMDs, Saccharopolyspora was the dominant microbiota which secreted S8 endopeptidase, M14, M15, S10, S13 carboxypeptidases, M1, M28, S15 aminopeptidases, and antioxidant enzymes, while in the fermentation of high moisture SMDs, Bacillus and Cerasibacillus were dominant genera which mainly secreted S8 endopeptidase and antioxidant enzymes. The abundance of ARGs and mobile genetic elements decreased significantly at thermophilic phase, with maximum drops of 93.7% and 99.9%, respectively. Maintaining moisture content below 30% at the end phase could prevent the transmission of ARGs effectively.

Traditional fermented foods as vehicle of non-dairy probiotics: Perspectives in South East Asia countries

Food fermentation is a food processing technology that utilizes the growth and metabolic activity of microorganisms for the stabilization and transformation of food materials. Notwithstanding, the technology has evolved beyond food preservation into a tool for creating desirable organoleptic, nutritional, and functional attributes in food products. This narrative review outlines a compilation of traditional fermented foods which available in the South East Asia (SEA) regions as a source vehicle for non-dairy probiotics. The nutritional values of traditional fermented foods are well-appreciated, especially in the resource-poor regions. The sensory and organoleptic preferences of traditional fermented foods as means of dietary routine variations were demonstrated. Furthermore, the evidence underlying its potent impacts on public health promotion and disease prevention is outlined. Lastly, the challenges and future prospects for the integration of traditional fermented foods practice are elucidated.

Probiotic Potential, Safety Properties, and Antifungal Activities of Corynebacterium amycolatum ICIS 9 and Corynebacterium amycolatum ICIS 53 Strains

The purpose of this study was to evaluate the probiotic characteristics and safety and to study the antifungal activity of C. amycolatum ICIS 9 and C. amycolatum ICIS 53 against Candida spp. The probiotic potential and safety properties were assessed by standard parameters. Both strains showed good survival at pH 3 for 3 h and high tolerance to 0.3% bile salts after 4 h of incubation. The indicators of hydrophobicity, autoaggregation, and surface tension for ICIS 9 were 89.43% (n-hexane) and 73.96% (xylene) and ranged from 13.13 to 39.86% and 34.27 mN/m, respectively. For ICIS 53, they were 59.95% (n-hexane) and 45.68% (xylene), from 35.58 to 51.53% and 32.40 mN/m, respectively. The strains ICIS 9 and ICIS 53 exhibited varying levels of coaggregation with all eight examined bacterial pathogens. The ICIS 9 strain was resistant to amikacin, amoxicillin, clarithromycin, chloramphenicol, ciprofloxacin, and gentamycin. ICIS 53 was resistant only to ciprofloxacin. The cell-free supernatant of strains ICIS 9 and ICIS 53 showed good antimicrobial and antibiofilm activity against 10 pathogenic vaginal and intestinal isolates of Candida spp. The CFS of ICIS 9 was more active against intestinal isolates, and the CFS of ICIS 53 showed good antimicrobial activity against vaginal isolates while inhibiting the growth of 2 out of 5 Candida spp. isolated from the intestine. Both of the strains were capable of reducing the biofilm formation of Candida fungi. In the case of the vaginal isolates of C. krusei V1, the results showed that the inhibition levels of ICIS 9 and ICIS 53 were 36.75 and 11.4%, respectively. In the case of C. albicans (V2, V3, V7, and V8), the inhibition of biofilm formation was no more than 7.07%. ICIS 9 and ICIS 53 also significantly inhibited biofilm formation of C. krusei 2613 intestinal isolates by 42.75 and 41.87%, respectively, with ICIS 9 inhibiting biofilm formation of C. albicans (2607, 2311, 2615, and 2615) from 3.38 to 15.69% and ICIS 53 from 5.95 to 23.48%. None of the strains showed DNase, haemolytic, or gelatinase activities. The results obtained revealed that ICIS 9 and ICIS 53 have safe properties and have the potential to be developed as probiotics.

Aggrandizement of fermented cucumber through the action of autochthonous probiotic cum starter strains of Lactiplantibacillus plantarum and Pediococcus pentosaceus

Purpose

Cucumber fermentation is traditionally done using lactic acid bacteria. The involvement of probiotic cultures in food fermentation guarantees enhanced organoleptic properties and protects food from spoilage.

Methods

Autochthonous lactic acid bacteria were isolated from spontaneously fermented cucumber and identified to species level. Only strains adjudged as safe for human consumption were examined for their technological and functional characteristics. Strain efficiency was based on maintaining high numbers of viable cells during simulated GIT conditions and fermentation, significant antioxidant activity, EPS production, nitrite degradation, and antimicrobial ability against Gram-positive and Gram-negative foodborne pathogens.

Result

Two strains, Lactiplantibacillus plantarum NPL 1258 and Pediococcus pentosaceus NPL 1264, showing a suite of promising functional and technological attributes, were selected as a mixed-species starter for carrying out a controlled lactic acid fermentations of a native cucumber variety. This consortium showed a faster lactic acid-based acidification with more viable cells, at 4% NaCl and 0.2% inulin (w/v) relative to its constituent strains when tested individually. Sensory evaluation rated the lactofermented cucumber acceptable based on texture, taste, aroma, and aftertaste.

Conclusion

The results suggest that the autochthonous LAB starter cultures can shorten the fermentation cycle and reduce pathogenic organism’ population, thus improving the shelf life and quality of fermented cucumber. The development of these new industrial starters would increase the competitiveness of production and open the country’s frontiers in the fermented vegetable market.

Characterization of Probiotic Properties of Antifungal Lactobacillus Strains Isolated from Traditional Fermenting Green Olives

The aim of this work is to characterize the potential probiotic properties of 14 antifungal Lactobacillus strains isolated from traditional fermenting Moroccan green olives. The molecular identification of strains indicated that they are composed of five Lactobacillus brevis, two Lactobacillus pentosus, and seven Lactobacillus plantarum. In combination with bile (0.3%), all the strains showed survival rates (SRs) of 83.19-56.51% at pH 3, while 10 strains showed SRs of 31.67-64.44% at pH 2.5. All the strains demonstrated high tolerance to phenol (0.6%) and produced exopolysaccharides. The autoaggregation, hydrophobicity, antioxidant activities, and surface tension value ranges of the strains were 10.29-41.34%, 15.07-34.67%, 43.11-52.99%, and 36.23-40.27 mN/m, respectively. Bacterial cultures exhibited high antifungal activity against Penicillium sp. The cell-free supernatant (CFS) of the cultures showed important inhibition zones against Candida pelliculosa (18.2-24.85 mm), as well as an antibacterial effect against some gram-positive and gram-negative bacteria (10.1-14.1 mm). The neutralized cell-free supernatant of the cultures displayed considerable inhibitory activity against C. pelliculosa (11.2-16.4 mm). None of the strains showed acquired or horizontally transferable antibiotic resistance or mucin degradation or DNase, hemolytic, or gelatinase activities. Lactobacillus brevis S82, Lactobacillus pentosus S75, and Lactobacillus plantarum S62 showed aminopeptidase, β-galactosidase, and β-glucosidase activities, while the other enzymes of API-ZYM were not detected. The results obtained revealed that the selected antifungal Lactobacillus strains are considered suitable candidates for use both as probiotic cultures for human consumption and for starters and as biopreservative cultures in agriculture, food, and pharmaceutical industries.

Dysbiosis of Gut Microbiota in Patients With Acute Myocardial Infarction

Acute myocardial infarction (AMI) continues as the main cause of morbidity and mortality worldwide. Interestingly, emerging evidence highlights the role of gut microbiota in regulating the pathogenesis of coronary heart disease, but few studies have systematically assessed the alterations and influence of gut microbiota in AMI patients. As one approach to address this deficiency, in this study the composition of fecal microflora was determined from Chinese AMI patients and links between gut microflora and clinical features and functional pathways of AMI were assessed. Fecal samples from 30 AMI patients and 30 healthy controls were collected to identify the gut microbiota composition and the alterations using bacterial 16S rRNA gene sequencing. We found that gut microflora in AMI patients contained a lower abundance of the phylum Firmicutes and a slightly higher abundance of the phylum Bacteroidetes compared to the healthy controls. Chao1 (P = 0.0472) and PD-whole-tree (P = 0.0426) indices were significantly lower in the AMI versus control group. The AMI group was characterized by higher levels of the genera Megasphaera, Butyricimonas, Acidaminococcus, and Desulfovibrio, and lower levels of Tyzzerella 3, Dialister, [Eubacterium] ventriosum group, Pseudobutyrivibrio, and Lachnospiraceae ND3007 group as compared to that in the healthy controls (P < 0.05). The common metabolites of these genera are mostly short-chain fatty acids, which reveals that the gut flora is most likely to affect the occurrence and development of AMI through the short-chain fatty acid pathway. In addition, our results provide the first evidence revealing remarkable differences in fecal microflora among subgroups of AMI patients, including the STEMI vs. NSTEMI, IRA-LAD vs. IRA-Non-LAD and Multiple (≥2 coronary stenosis) vs. Single coronary stenosis groups. Several gut microflora were also correlated with clinically significant characteristics of AMI patients, including LVEDD, LVEF, serum TnI and NT-proBNP, Syntax score, counts of leukocytes, neutrophils and monocytes, and fasting serum glucose levels. Taken together, the data generated enables the prediction of several functional pathways as based on the fecal microfloral composition of AMI patients. Such information may enhance our comprehension of AMI pathogenesis.

Lactiplantibacillus plantarum strains isolated from spontaneously fermented cocoa exhibit potential probiotic properties against Gardnerella vaginalis and Neisseria gonorrhoeae

Background

Probiotics are important tools in therapies against vaginal infections and can assist traditional antibiotic therapies in restoring healthy microbiota. Recent research has shown that microorganisms belonging to the genus Lactobacillus have probiotic potential. Thus, this study evaluated the potential in vitro probiotic properties of three strains of Lactiplantibacillus plantarum, isolated during the fermentation of high-quality cocoa, against Gardnerella vaginalis and Neisseria gonorrhoeae. Strains were evaluated for their physiological, safety, and antimicrobial characteristics.

Results

The hydrophobicity of L. plantarum strains varied from 26.67 to 91.67%, and their autoaggregation varied from 18.10 to 30.64%. The co-aggregation of L. plantarum strains with G. vaginalis ranged from 14.73 to 16.31%, and from 29.14 to 45.76% with N. gonorrhoeae. All L. plantarum strains could moderately or strongly produce biofilms. L. plantarum strains did not show haemolytic activity and were generally sensitive to the tested antimicrobials. All lactobacillus strains were tolerant to heat and pH resistance tests. All three strains of L. plantarum showed antimicrobial activity against the tested pathogens. The coincubation of L. plantarum strains with pathogens showed that the culture pH remained below 4.5 after 24 h. All cell-free culture supernatants (CFCS) demonstrated activity against the two pathogens tested, and all L. plantarum strains produced hydrogen peroxide. CFCS characterisation in conjunction with gas chromatography revealed that organic acids, especially lactic acid, were responsible for the antimicrobial activity against the pathogens evaluated.

Conclusion

The three strains of L. plantarum presented significant probiotic characteristics against the two pathogens of clinical importance. In vitro screening identified strong probiotic candidates for in vivo studies for the treatment of vaginal infections.

Bioprospecting of Palmyra Palm (Borassus flabellifer) Nectar: Unveiling the Probiotic and Therapeutic Potential of the Traditional Rural Drink

The present study investigates the therapeutic and probiotic attributes of traditional Toddy Palm Nectar (TPN). Glucose was found to be the highest with 4.37 mg/ml and arabinose was the least with 2.85 mg/ml. The average ethanol concentration of fresh TPN was found to be 0.3 mg/ml. The nutritional profile of TPN revealed 18 volatile fatty acids, the major one being hexadecenoic acid (M/Z 74). Amino acid profiling showed 26 amino acids, with OH-lysine-2 the highest (12.86%). About 120 morphologically distinct lactic acid bacteria (LAB) were isolated from 26 TPN samples, based on differential growth and in vitro probiotic characteristics. After 16S rRNA sequencing, four indigenous LAB strains were identified as Lactobacillus plantarum group OUBN1, Enterococcus faecium OUBN3, Pediococcus acidilactici OUBN4, and Pediococcus pentosaceous OUBN5 and their sequences were deposited to NCBI. Microbiological safety evaluation studies showed the absence of hemolytic, gelatinolytic and proteolytic activity. The bacterial isolate OUBN3 showed a maximum survival rate of 6.91 ± 0.04 log cfu/ml at acidic pH 2.5 and isolate OUBN5 showed 6.94 ± 0.02 log cfu/ml at pH 3.0. Similarly, the isolate OUBN5 showed 7.92 ± 0.03 log cfu/ml to 0.3% ox-bile after 4 h and 8.94 ± 0.03 log cfu/ml to simulated gastric juice after 3 h of treatments. OUBN1 expressed the highest autoaggregation (81.76 ± 1.25%), cell surface hydrophobicity (79.71 ± 3.42%), and displayed the maximum coaggregation with E. coli MTCC452 (76.96%), K. pneumoniae MTCC109 (75.62%), and S. aureus MTCC902 (70.69%). All strains showed significant antibiotic and antimicrobial activity. Isolate OUBN1 displayed hydroxyl radical scavenging activity (68.71 ± 1.0%) with an IC₅₀ value of 75.62 μg/ml and the highest anti-cancer activity (percentage inhibition of 88.55) against HT-29 cells. Based on the characteristics observed, L. plantarum group OUBN1 and P. pentosaceous OUBN5 were found to be potential isolates to employ as probiotic microbiota in food and forage preparations. These findings reinforce the fact that LAB isolated from TPN could be exploited as an alternative means toward potential therapeutic applications.

Metataxonomic analysis of microbiota from Pakistani dromedary camelids milk and characterization of a newly isolated Lactobacillus fermentum strain with probiotic and bio-yogurt starter traits

This study was undertaken to investigate the starter and probiotic potential of lactic acid bacteria isolated from dromedarian camel's milk using both culture-dependent and -independent approaches and metataxonomic analysis. Strains of lactic acid bacteria recovered were examined in vitro for tolerance to gastric acidity, bile, and lysozyme. Bile salt hydrolysis, serum cholesterol-lowering, oxalate degradation, proteolytic activity, exopolysaccharide production, and cell surface characteristics necessary for colonizing intestinal mucosa were also evaluated. A single strain of the species, Lactobacillus fermentum named NPL280, was selected through multivariate analysis as it harbored potential probiotic advantages and fulfilled safety criteria. The strain assimilated cholesterol, degraded oxalate, produced exopolysaccharides, and proved to be a proficient alternate yogurt starter with good viability in stored bio-yogurt. A sensorial analysis of the prepared bio-yogurt was also found to be exemplary. We conclude that the indigenous L. fermentum strain NPL280 has the desired traits of a starter and adjunct probiotic culture for dairy products.

Weissella: An Emerging Bacterium with Promising Health Benefits

Weissella strains have been the subject of much research over the last 5 years because of the genus' technological and probiotic potential. Certain strains have attracted the attention of the pharmaceutical, medical, and food industries because of their ability to produce antimicrobial exopolysaccharides (EPSs). Moreover, Weissella strains are able to keep foodborne pathogens in check because of the bacteriocins, hydrogen peroxide, and organic acids they can produce; all listed have recognized pathogen inhibitory activities. The Weissella genus has also shown potential for treating atopic dermatitis and certain cancers. W. cibaria, W. confusa, and W. paramesenteroides are particularly of note because of their probiotic potential (fermentation of prebiotic fibers) and their ability to survive in the gastrointestinal tract. It is important to note that most of the Weissella strains with these health-promoting properties have been shown to be save safe, due to the absence or the low occurrence of virulence or antibiotic-resistant genes. A large number of scientific studies continue to report on and to support the use of Weissella strains in the food and pharmaceutical industries. This review provides an overview of these studies and draws conclusions for future uses of this rich and previously unexplored genus.

Probiotic characterization of bacterial strains from fermented South Indian tomato pickle and country chicken intestine having antioxidative and antiproliferative activities

AIM

The present study aims to evaluate the potential antioxidant and antiproliferative properties of probiotic bacterial isolates Weissella cibaria p3B, Bacillus subtilis CS, and Bacillus tequilensis CL, isolated from South Indian fermented tomato pickle (homemade) and gut content of indigenous country chicken.

METHODS AND RESULTS

The bacterial isolates exhibited antimicrobial activity against food-borne, human pathogenic bacteria, along with better survival under different bile and acidic conditions, hydrophobicity towards several hydrocarbons, and adherence to intestinal epithelial cells (INT-407 cells). Also, the intact cell (IC) mixture of the three species showed better DPPH, ABTS, and Fe²⁺ chelating activity as compared to the individual IC or cell extract (CE) activity. Among the three bacterial species, W. cibaria p3B revealed maximum antiproliferative activity against HeLa and Caco-2 cancer cells, all of which were nontoxic to INT-407 cells. Apart from being non-hemolytic, the bacterial isolates did not display any necrotic inhibition in HeLa and Caco-2 cells. The cell free supernatant (CFS) of the three bacterial isolates were tested for the production of antimicrobial peptides or bacteriocins. It found that the CFS of bacterial isolates was stable at various temperature, pH and sensitive to proteolytic enzymes confirms protenoius in nature of the antimicrobil peptides or bacteriocins.

CONCLUSION

The bacterial isolates showed promising antimicrobial, antioxidant as well as antiproliferative activities with better survival ability at different pH and bile concentrations. The three bacterial isolates were able to produce potential antimicrobial peptides or bacteriocins.

SIGNIFICANCE AND IMPACT OF THE STUDY

These results indicate better compatibility of our bacterial isolates against synthetic drugs to avoid adverse side effects and can be processed as dietary supplements against food and human pathogens. They can also provide antioxidative and antiproliferative benefits to humans and animals.

Characterization of High-Ornithine-Producing Weissella koreensis DB1 Isolated from Kimchi and Its Application in Rice Bran Fermentation as a Starter Culture

High-ornithine-producing Weissella koreensis DB1 were isolated from kimchi. Ornithine is produced from arginine via the intracellular arginine deiminase pathway in microorganisms; thus, high cell growth is important for producing ornithine in large quantities. In this study, excellent W. koreensis DB1 growth (A600: 5.15-5.39) was achieved in de Man, Rogosa, and Sharpe (MRS) medium supplemented with 1.0-3.0% arginine (pH 5.0) over 24-48 h at 30 °C, and the highest ornithine (15,059.65 mg/L) yield was obtained by culture in MRS containing 3.0% arginine for 48 h. W. koreensis DB1 was further investigated as a functional starter culture for rice bran fermentation. After 48 h of fermentation at 30 °C, the fermented rice bran was freeze-dried and ground. The prepared fermented rice bran contained 43,074.13 mg/kg of ornithine and 27,336.37 mg/kg of citrulline, which are used as healthcare supplements due to their beneficial effects. Furthermore, the organoleptic quality of the fermented rice bran was significantly improved, and the fermented product contained viable cells (8.65 log CFU/mL) and abundant dietary fiber. In addition, an investigation of its safety status showed that it has no harmful characteristics. These results indicate that the fermented rice bran product produced is a promising functional food candidate.

Determination of competition and adhesion abilities of lactic acid bacteria against gut pathogens in a whole-tissue model

In an intestinal system with a balanced microbial diversity, lactic acid bacteria (LAB) are the key element which prevents the colonization and invasion of gut pathogens. Adhesion ability is important for the colonization and competition abilities of LAB. The aim of this study was to determine the adhesion and competition abilities of LAB by using a whole-tissue model. Indigenous strains were isolated from spontaneously fermented foods like cheese and pickles. The aggregation and competition abilities of the isolates were determined, as well as their resistance to gastrointestinal conditions. Four Lactobacillus strains and one Weissella strain were found to be highly competitive against three major gut pathogens, namely Clostridium difficile, Listeria monocytogenes and Salmonella Enteritidis. Tested strains decreased the number of pathogens to below their disease-causing levels. According to the results, the numbers of C. difficile and L. monocytogenes bacteria decreased by an average of 3 log, and their adhesion rates decreased by approximately 50%. However, the number of S. Enteritidis bacteria was decreased by only 1 log compared with its initial number. We thought that the weak effect on Salmonella was due to its possession of many virulence factors. The results showed that natural isolates from sources other than human specimens like the Weissella strain in this study were quite competent when compared with the human isolates in terms of their adhesion to intestines and resistance to gastrointestinal tract conditions. It was also revealed that a whole-tissue model with all-natural layers can be successfully used in adhesion and competition tests.

Characterization of Weissella koreensis SK Isolated from Kimchi Fermented at Low Temperature (around 0 °C) Based on Complete Genome Sequence and Corresponding Phenotype

This study identified lactic acid bacteria (LAB) that play a major role in kimchi fermented at low temperature, and investigated the safety and functionality of the LAB via biologic and genomic analyses for its potential use as a starter culture or probiotic. Fifty LAB were isolated from 45 kimchi samples fermented at -1.5~0 °C for 2~3 months. Weissella koreensis strains were determined as the dominant LAB in all kimchi samples. One strain, W. koreensis SK, was selected and its phenotypic and genomic features characterized. The complete genome of W. koreensis SK contains one circular chromosome and plasmid. W. koreensis SK grew well under mesophilic and psychrophilic conditions. W. koreensis SK was found to ferment several carbohydrates and utilize an alternative carbon source, the amino acid arginine, to obtain energy. Supplementation with arginine improved cell growth and resulted in high production of ornithine. The arginine deiminase pathway of W. koreensis SK was encoded in a cluster of four genes (arcA-arcB-arcD-arcC). No virulence traits were identified in the genomic and phenotypic analyses. The results indicate that W. koreensis SK may be a promising starter culture for fermented vegetables or fruits at low temperature as well as a probiotic candidate.

Multifarious cholesterol lowering potential of lactic acid bacteria equipped with desired probiotic functional attributes

Lactic acid bacteria (LAB) isolates possessed functional probiotic attributes, such as high hydrophobicity and autoaggregation ability, coaggregation capability with bacterial pathogens, antimicrobial activity, antioxidant potential, and hypocholesterolemic effects. Selected potential probiotic LAB, i.e. Lactobacillus paracasei M3, L. casei M5, L. paracasei M7, and few others were studied for their ability to lower cholesterol using a number of methods viz. cholesterol assimilation, bile salt deconjugation, cholesterol co-precipitation, cholesterol adhesion to probiotic cell wall, and miceller sequestration of cholesterol. L. casei M5 showed maximum bile salt hydrolase (BSH) activity, and released 57.63 nmol of glycine/min, and was closely followed by LAB isolate M9 which generated 52.12 nmol of glycine/min. Sodium glycocholate was deconjugated by L. casei M5 to produce 27.77 μmol/mL of cholic acid, while other isolates produced 20-26 μmol/mL of cholic acid. Cholesterol was assimilated significantly by isolate M6 (82.15%) and L. casei M5 (76.51%). L. casei M5 showed higher cholesterol co-precipitation ability (50.16 μg/mL) as compared to other LAB isolates (33-44 μg/mL). Miceller cholesterol concentration was reduced maximally by LAB isolate M8 (87.5%), followed by isolates M5 (84.75%), M9 (84%), M10 (80%), and M37 (79%). Higher cell wall adhesion of cholesterol was realized by L. casei M5 (42.48 μg/mL) than other LAB isolates (30-40 μg/mL). Selected LAB probiotics demonstrated short chain fatty acid (acetate, propionate, and butyrate) producing ability, yet another way of probiotics-mediated cholesterol lowering.

Tannin-Tolerant and Extracellular Tannase Producing Bacillus Isolated from Traditional Fermented Tea Leaves and Their Probiotic Functional Properties

A total of 117 Bacillus strains were isolated from Miang, a culture relevant fermented tea of northern Thailand. These strains were collected from 16 sampling sites in north Thailand. In this collection 95 isolates were tannin-tolerant Bacillus capable of growth on nutrient agar supplemented with 0.5% (w/v) total tannins from tea leaves extract (TE). The strains were also positive for pectinase, xylanase and amylase activity, while 91 and 86 isolates were positive for cellulase and β-mannanase, respectively. Only 21 isolates producing extracellular tannase were selected for further characterization. Identification by 16S rRNA gene sequence analysis revealed that more than 50% (11 of 21 isolates) were Bacillustequilensis, whereas the remaining were B. siamensis (3), B. megaterium (3), B. aryabhattai (3) and B. toyonensis (1). B. tequilensis K34.2 produced the highest extracellular tannase activity of 0.60 U/mL after cultivation at 37 °C for 48 h. In addition, all 21 isolates were resistant to 0.3% (w/v) bile salt, sensitive to gentamicin, erythromycin, vancomycin and kanamycin and also tolerant to acidic condition. Cell hydrophobicity varied from 9.4 to 80.4% and neutralized culture supernatants of some Bacillus isolates showed bacteriocin producing potentiality against Samonella enterica serovar Typhimurium TISTR 292. All tested probiotic properties indicated that B. tequilensis K19.3, B. tequilensis K34.2 and B. siamensis K19.1 had high probiotic potential. This is the first report describing tannin-tolerant Bacillus and their extracellular tannase producing capability in Miang, a traditional fermented tea of Thailand.

Probiotics of Diverse Origin and Their Therapeutic Applications: A Review

The increased awareness about the harmful effects of excessive use of antibiotics has created an interest in probiotics due to its beneficial effects on gut microbiota. These advantages of probiotics have attracted researchers to find out effects on human metabolism and their role in the treatment of diverse types of diseases or disorders. Additionally, they are clinically used as biocontrol agents in the treatment of mental disorders, anticancer agents and in decreasing the threat of necrotizing enterocolitis in premature infants. In this review, we have focused on various kinds of probiotics and various nondairy substrates for their production. We have also included the importance of probiotics in the treatment of metabolic disorders, type II diabetes and infectious diseases. Furthermore, this review emphasizes applications of probiotics originated from different organisms. Their future health perspectives are discussed to gain insight into their applications.KEY TEACHING POINTSThe global market of probiotics is enormously rising day by day due to its highly beneficial effect on human microbiota.Additionally, these are used as biocontrol agents; mental disorders prevent cancer and decrease the threat of necrotizing enterocolitis (NEC) in premature infants.This review focuses on various kinds of sources of probiotics and various non-dairy substrates for the production of probiotics.The importance of probiotics in the treatment of metabolic disorders, type II diabetes control, cancer and treatment of infectious diseases are also described.It emphasizes diversified probiotics and their applications in various human health aspects and future perspectives.

Lactobacillus fermentum strains of dairy-product origin adhere to mucin and survive digestive juices

Introduction. There is an ever present need to isolate and characterize indigenous bacterial strains with potential probiotic health benefits for humans.Aim. Lactobacillus fermentum of dairy origin was focused because of its propensity to adhere to the intestinal glycoprotein, mucin.Methodology. The lactobacillus strains were screened for mucin adhesion, resistance to low pH and bile, autoaggregation, hydrophobicity, and survival in an in vitro digestion model. The cholesterol-lowering and oxalate-degrading effects of selected strains were also determined. Safety was assessed for haemolytic, mucinolytic and gelatinase activity, biogenic amine production, antibiotic resistance and phenol resistance. Expression of the 32-mmub adhesion-related gene was also measured following strain exposure to simulated gastrointestinal tract (GIT) digestion.Results. The selected mucin-adhesive strains were tolerant to acid (pH 3.0) and bile (0.25 %) and demonstrated >85 % survival following simulated human digestion in the presence of milk. The digestive treatment did not affect the adhesive potential of PL20, and PL27, regardless of the food matrix. The simulated digestion had less effect on their adhesion than on the type strain and it also did not correlate with the mmub gene expression level as determined by qPCR. The selected strains exhibited cholesterol removal (36-44 %) and degraded oxalate (66-55 %). Neither of these strains exhibited undesirable characteristics.Conclusion. These preliminary findings suggest a functionality in the two strains of L. fermentum with high colonization potential on GIT mucosal membranes and possible health-promoting effects. This prima facie evidence suggests the need for further studies to test these probiotic candidates as live biotherapeutic agents in vivo.

Differential Effects of Typical Korean Versus American-Style Diets on Gut Microbial Composition and Metabolic Profile in Healthy Overweight Koreans: A Randomized Crossover Trial

The Westernized diet has been associated with the pathogenesis of metabolic diseases, whereas a Korean diet has been reported to exert beneficial effects on health in several studies. However, the effects of Western and Korean diets on the gut microbiome and host metabolome are unclear. To examine the diet-specific effects on microbiome and metabolome, we conducted a randomized crossover clinical trial of typical Korean diet (TKD), typical American diet (TAD), and recommended American diet (RAD). The trial involved a 4-week consumption of an experimental diet followed by a 2-week interval before diet crossover. 16S rRNA sequencing analysis identified 16, 10, and 14 differential bacteria genera specific to TKD, RAD, and TAD, respectively. The Firmucutes-Bacteroidetes ratio was increased by TKD. Nuclear magnetic resonance metabolome profiling revealed that TKD enriched branched chain amino acid metabolism, whereas ketone body metabolism was evident in RAD and TAD. Microbiome and metabolome responses to the experimental diets varied with individual enterotypes. These findings provide evidence that the gut microbiome and host metabolome rapidly respond to different cultural diets. The findings will inform clarification of the diet-related communication networks of the gut microbiome and host metabolome in humans.

Probiotic Potential and Safety Evaluation of Enterococcus faecalis OB14 and OB15, Isolated From Traditional Tunisian Testouri Cheese and Rigouta, Using Physiological and Genomic Analysis

Lactic acid bacteria (LAB) strains OB14 and OB15 were isolated from traditional Tunisian fermented dairy products, Testouri cheese and Rigouta, respectively. They were identified as Enterococcus faecalis by the MALDI TOF-MS (matrix assisted laser desorption-ionization time of flight mass spectrometry) biotyper system and molecular assays (species-specific PCR). These new isolates were evaluated for probiotic properties, compared to E. faecalis Symbioflor 1 clone DSM 16431, as reference. The bacteria were found to be tolerant to the harsh conditions of the gastrointestinal tract (acidity and bile salt). They were low to moderate biofilm producers, can adhere to Caco-2/TC7 intestinal cells and strengthen the intestinal barrier through the increase of the transepithelial electrical resistance (TER). Susceptibility to ampicillin, vancomycin, gentamicin and erythromycin has been tested using the broth microdilutions method. The results demonstrated that E. faecalis OB14 and OB15 were sensitive to the clinically important ampicillin (MIC = 1 μg/mL) and vancomycin (MIC = 2 μg/mL) antibiotics. However, Whole Genome Sequencing (WGS) showed the presence of tetracycline resistance and cytolysin genes in E. faecalis OB14, and this led to high mortality of Galleria Mellonella larvae in the virulence test. Hierarchical cluster analysis by MALDI TOF-MS biotyper showed that E. faecalis OB15 was closely related to the E. faecalis Symbioflor 1 probiotic strain than to OB14, and this has been confirmed by WGS using the average nucleotide identity (ANI) and Genome-to-Genome Hybridization similarity methods. According to these results, E. faecalis OB15 seems to be reliable for future development as probiotic, in food or feed industry.

Hepatoprotective effects of synbiotic soy yogurt on mice fed a high-cholesterol diet

OBJECTIVES

The role of probiotic yogurt in the prevention and treatment of hypercholesterolemia has attracted global attention. Mounting evidence has indicated that probiotics and prebiotics improve lipid metabolism by lowering low-density lipoprotein cholesterol concentration in plasma of hypercholesterolemic patients. The present study aimed to develop synbiotic soy yogurt that had a greater cholesterol-lowering effect in hypercholesterolemic mice compared with control soy yogurt.

METHODS

Synbiotic soy yogurt was prepared using soy milk and synbiotic capsule containing LactoBacil Plus (SCLBP) probiotic cultures and fructo-oligosaccharide. Synbiotic soy yogurt was analyzed for proximate composition and microbiological and antioxidative properties during storage periods of 28 d. To study hypocholesterolemic effect, hypercholesterolemia was induced in mice with administration of 1.25% cholesterol and 0.5% cholic acid for 4 wk. After that 24 male Balb/c mice were randomly divided into four groups and fed basic, high-cholesterol, high-cholesterol with soy yogurt, or high-cholesterol with synbiotic soy yogurt diet for 5 wk. Blood samples were collected to measure lipids concentration and oxidative and antioxidative status.

RESULTS

Proximate composition of SCLBP-formulated soy yogurt exhibits a marked difference from control soy yogurt in terms of total solids, moisture, protein, fat, ash, carbohydrate, and energy content. Results indicated that the 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity (75.28%) in synbiotic yogurt containing 2% SCLBP was significantly greater (P ≤ 0.05) compared with control soy yogurt (52.98%). In mice with hypercholesterolemia that were fed synbiotic soy yogurts, the yogurts had a favorable effect in reducing blood cholesterol, triglycerides, and low-density lipoprotein cholesterol and lipid peroxidation in liver. These led to a significant decrease of the atherogenic index compared with soy yogurt (control) only. Treatment with synbiotic soy yogurt cultures ameliorates lipid peroxidation in liver.

CONCLUSIONS

These results indicated that the synbiotic soy yogurts have beneficial effects against hypercholesteroemia and can be used as a therapeutic agent in hypercholesteremic patients.

Beneficial properties of lactic acid bacteria naturally present in dairy production

BACKGROUND

Consumers are increasingly demanding for natural and beneficial foods, in order to improve their health and well-being. Probiotics play an important role in such demand, and dairy foods are commonly used as vehicles for such bacteria, represented predominantly by lactic acid bacteria. Due to consumers demand, food industry is constantly looking for novel bacterial strains, leading to studies that aims the isolation and characterization of their beneficial features. This study aimed to characterize the naturally occurring lactic acid bacteria obtained from a dairy environment, in order to assess their potential use as probiotics.

RESULTS

Preliminary screening and PCR analysis, based on 16S rRNA sequencing, were applied to select and identify 15 LAB strains from the genera Lactobacillus (n = 11), Pediococcus (n = 2) and Weissella (n = 2). All strains showed resistance to low pH and the evaluated bile salt concentrations in vitro. The API ZYM test characterized the enzymatic activity of the strains, and a high β-galactosidase activity was observed in 13 strains. All strains presented resistance to simulated gastric (3 h) and intestinal (4 h) conditions in vitro, the ability to auto- and co-aggregate with indicator microorganisms and a high cell surface hydrophobicity. Most of the strains were positive for map and EFTu beneficial genes. All strains exhibited strong deconjugation of bile salts in vitro and all assimilated lactose.

CONCLUSIONS

The phenotypes exhibited in vitro and the presence of beneficial genes revealed the beneficial potential of the studied strains, demanding further analyses in a food matrix and in vivo to allow the development of a functional product, with health-related properties.

In vitro Assessment of the Probiotic Properties and Bacteriocinogenic Potential of Pediococcus pentosaceus MZF16 Isolated From Artisanal Tunisian Meat "Dried Ossban"

Pediococcus pentosaceus MZF16 has been isolated from artisanal Tunisian meat so called "Dried Ossban," an original ecological niche, and identified by MALDI-TOF mass spectrometry and 16S rDNA sequencing. This bacterium showed a high tolerance to gastric stress conditions, and toward bile salts. P. pentosaceus MZF16 also demonstrated a hydrophobic surface profile (high adhesion to xylene), autoaggregation, and adhesive abilities to the human intestinal Caco-2/TC7 cell line. These properties may help the bacterium colonizing the gut. Furthermore, MZF16 was found to be resistant to gentamycin and chloramphenicol but did not harbor any transferable resistance determinants and/or virulence genes. The data also demonstrated absence of cytotoxicity of this strain. Conversely, P. pentosaceus MZF16 can slightly stimulate the immune system and enhance the intestinal epithelial barrier function. Moreover, this bacterium has been shown to be highly active against Listeria spp. due to bacteriocin production. Characterization of the bacteriocin by PCR amplification, sequencing and bioinformatic analyses revealed that MZF16 produces a bacteriocin 100% identical to coagulin, a pediocin-like inhibitory substance produced by Bacillus coagulans. To our knowledge, this is the first report that highlights the production of a pediocin 100% identical to coagulin in a Pediococcus strain. As coagulin, pediocin MZF16 has the consensus sequence YYGNGVXCXXXXCXVXXXXA (X denotes any amino acid), which confirms its belonging to class IIa bacteriocins, and its suitability to preserve foods from Listeria monocytogenes development. According to these results, P. pentosaceus MZF16 can be proposed as a probiotic and bioprotective agent for fermented foods, including Tunisian dry meat and sausages. Further investigations will aim to study the behavior of this strain in meat products as a component of functional food.

Antagonistic Activities and Probiotic Potential of Lactic Acid Bacteria Derived From a Plant-Based Fermented Food

In this study, antagonistic activities and probiotic potential of lactic acid bacteria (LAB) derived from a plant-based fermented food, kimchi, were demonstrated. The cell free supernatants (CFS) from Lactobacillus curvatus KCCM 43119, Leuconostoc mesenteroides KCCM 43060, Weissella cibaria KCTC 3746, and W. koreensis KCCM 41517 completely inhibited the growth of foodborne pathogenic bacteria, while neutralized CFS (pH 6.5) partially inhibited the growth. The competition, exclusion, and displacement of foodborne pathogenic bacteria by the LAB strains from adhesion to HT-29 cells were investigated. The LAB strains were able to compete with, exclude, and displace the foodborne pathogenic bacteria. However, the degree of inhibition due to the adhesion was found to be a LAB strain-dependent phenomenon. The LAB strains showed high coaggregation with foodborne pathogenic bacteria, and they also exhibited high resistance to acidic condition. Except W. cibaria KCTC 3746, all LAB strains were capable of surviving in the presence of bile salts. Furthermore, while all LAB strains were resistant to chloramphenicol, kanamycin, streptomycin, gentamicin, and erythromycin, only W. cibaria KCTC 3746 and W. koreensis KCCM 41517 displayed resistance to vancomycin. These results suggest that the LAB strains derived from kimchi exerted antagonistic activities against foodborne pathogenic bacteria with probiotic potential.

Effects of Tempeh Fermentation with Lactobacillus plantarum and Rhizopus oligosporus on Streptozotocin-Induced Type II Diabetes Mellitus in Rats

The increased consumption of high fat-containing foods has been linked to the prevalence of obesity and abnormal metabolic syndromes. Rhizopus oligosporus, a fungus in the family Mucoraceae, is widely used as a starter for homemade tempeh. Although R. oligosporus can prevent the growth of other microorganisms, it grows well with lactic acid bacteria (LAB). Lactobacillus plantarum can produce β-glucosidase, which catalyzes the hydrolysis of glucoside isoflavones into aglycones (with greater bioavailability). Therefore, the development of a soybean-based functional food by the co-inoculation of R. oligosporus and L. plantarum is a promising approach to increase the bioactivity of tempeh. In this study, the ameliorative effect of L. plantarum in soy tempeh on abnormal carbohydrate metabolism in high-fat diet (HFD)-induced hyperglycemic rats was evaluated. The co-incubation of L. plantarum with R. oligosporus during soy tempeh fermentation reduced the homeostatic model assessment of insulin resistance, HbA1c, serum glucose, total cholesterol, triglyceride, free fatty acid, insulin, and low-density lipoprotein contents, and significantly increased the high-density lipoprotein content in HFD rats. It also increased the LAB counts, as well as the bile acid, cholesterol, triglyceride, and short-chain fatty acid contents in the feces of HFD rats. Our results suggested that the modulation of serum glucose and lipid levels by LAB occurs via alterations in the internal microbiota, leading to the inhibition of cholesterol synthesis and promotion of lipolysis. Tempeh, which was produced with both L. plantarum and R. oligosporus, might be a beneficial dietary supplement for individuals with abnormal carbohydrate metabolism.

Evaluation of Probiotic Properties and Safety of Enterococcus faecium Isolated From Artisanal Tunisian Meat "Dried Ossban"

Enterococcus faecium strains were isolated from an original biotope, artisanal dried Tunisian meat “Dried Ossban,” and evaluated for safety and capacity as probiotics. Gram-positive, catalase negative, and bacteriocin-producing bacteria were screened using selective microbiological media. All isolates were identified by phenotypic and molecular tools. Five E. faecium strains (MZF1, MZF2, MZF3, MZF4, and MZF5) were selected and further assessed for their probiotic properties. They were found to be resistant to the physiological concentrations of bile salts, and the harsh conditions of the gastrointestinal tract, and showed autoaggregation and adhesion ability. All these isolates possess at least one enterocin and could efficiently inhibit the growth of Listeria innocua HPB13. The analysis of their safety profile revealed for almost all the strains the absence of cytotoxicity and virulence determinants, and susceptibility to clinically important antibiotics such as vancomycin. These data suggest that these bacteria, isolated from “Dried Ossban,” do not present a risk to human health, and may be considered as interesting candidates for future use as probiotics and bioprotective cultures for application in the food and/or feed industries.