Probiotic properties of lactic acid bacteria isolated from traditionally fermented Xinjiang cheese

Unlocking the Potential of Probiotics: A Comprehensive Review on Research, Production, and Regulation of Probiotics

This review provides a comprehensive overview of the current state of probiotic research, covering a wide range of topics, including strain identification, functional characterization, preclinical and clinical evaluations, mechanisms of action, therapeutic applications, manufacturing considerations, and future directions. The screening process for potential probiotics involves phenotypic and genomic analysis to identify strains with health-promoting properties while excluding those with any factor that could be harmful to the host. In vitro assays for evaluating probiotic traits such as acid tolerance, bile metabolism, adhesion properties, and antimicrobial effects are described. The review highlights promising findings from in vivo studies on probiotic mitigation of inflammatory bowel diseases, chemotherapy-induced mucositis, dysbiosis, obesity, diabetes, and bone health, primarily through immunomodulation and modulation of the local microbiota in human and animal models. Clinical studies demonstrating beneficial modulation of metabolic diseases and human central nervous system function are also presented. Manufacturing processes significantly impact the growth, viability, and properties of probiotics, and the composition of the product matrix and supplementation with prebiotics or other strains can modify their effects. The lack of regulatory oversight raises concerns about the quality, safety, and labeling accuracy of commercial probiotics, particularly for vulnerable populations. Advancements in multi-omics approaches, especially probiogenomics, will provide a deeper understanding of the mechanisms behind probiotic functionality, allowing for personalized and targeted probiotic therapies. However, it is crucial to simultaneously focus on improving manufacturing practices, implementing quality control standards, and establishing regulatory oversight to ensure the safety and efficacy of probiotic products in the face of increasing therapeutic applications.

Lactic acid bacteria in Asian fermented foods and their beneficial roles in human health

Fermented foods have been a staple in human diets for thousands of years, garnering attention for their health and medicinal benefits. Rich in lactic acid bacteria (LAB) with probiotic properties, these foods play a crucial role in positively impacting the host's gut microbiome composition and overall health. With a long history of safe consumption, fermented foods effectively deliver LAB to humans. Intake of LAB from fermented foods offers three main benefits: (1) enhancing digestive function and managing chronic gastrointestinal conditions, (2) modulating the immune system and offering anti-inflammatory effects to prevent immune-related diseases, and (3) synthesizing vitamins and various bioactive compounds to improve human health. In this review, we highlighted the diverse LAB present in Asian fermented foods and emphasized LAB-rich fermented foods as a natural and effective solution for health enhancement and disease prevention.

Lactiplantibacillus plantarum N4 ameliorates lipid metabolism and gut microbiota structure in high fat diet-fed rats

Lowing blood lipid levels with probiotics has good application prospects. This study aimed to isolate probiotics with hypolipidemic efficacy from homemade na dish and investigate their mechanism of action. In vitro experiments were conducted to determine the cholesterol-lowering ability of five isolates, with results showing that Lactiplantibacillus plantarum N4 exhibited a high cholesterol-lowering rate of 50.27% and significant resistance to acid (87%), bile salt (51.97%), and pepsin (88.28%) in simulated gastrointestinal fluids, indicating promising application prospects for the use of probiotics in lowering blood lipids. The findings from the in vivo experiment demonstrated that the administration of N4 effectively attenuated lipid droplet accumulation and inflammatory cell infiltration in the body weight and liver of hyperlipidemic rats, leading to restoration of liver tissue morphology and structure, as well as improvement in lipid and liver biochemical parameters. 16S analysis indicated that the oral administration of N4 led to significant alterations in the relative abundance of various genera, including Sutterella, Bacteroides, Clostridium, and Ruminococcus, in the gut microbiota of hyperlipidemia rats. Additionally, fecal metabolomic analysis identified a total of 78 metabolites following N4 intervention, with carboxylic acids and their derivatives being the predominant compounds detected. The transcriptomic analysis revealed 156 genes with differential expression following N4 intervention, leading to the identification of 171 metabolic pathways through Kyoto Encyclopedia of Genes and Genomes enrichment analysis. Notably, the glutathione metabolism pathway, PPAR signaling pathway, and bile secretion pathway emerged as the primary enrichment pathways. The findings from a comprehensive multi-omics analysis indicate that N4 influences lipid metabolism and diminishes lipid levels in hyperlipidemic rats through modulation of fumaric acid and γ-aminobutyric acid concentrations, as well as glutathione and other metabolic pathways in the intestinal tract, derived from both the gut microbiota and the host liver. This research offers valuable insights into the therapeutic potential of probiotics for managing lipid metabolism disorders and their utilization in the development of functional foods.

Antiparasitic Activity of Enterocin M and Durancin-like from Beneficial Enterococci in Mice Experimentally Infected with Trichinella spiralis

Beneficial/probiotic strains protect the host from pathogens by competitive displacement and production of antibacterial substances, i.e., bacteriocins. The antiparasitic potential of bacteriocins/enterocins and their producing strains in experimental murine trichinellosis were tested as a new therapeutic strategy. Enterocin M and Durancin-like and their producers Enterococcus faecium CCM8558 and Enterococcus durans ED26E/7 were administered daily to mice that were challenged with Trichinella spiralis. Our study confirmed the antiparasitic effect of enterocins/enterococci, which reduced the number of adults in the intestine (Enterocin M-43.8%, E. faecium CCM8558-54.5%, Durancin-like-16.4%, E. durans ED26E/7-35.7%), suppressed the Trichinella reproductive capacity ex vivo (Enterocin M-61%, E. faecium CCM8558-74%, Durancin-like-38%, E. durans ED26E/7-66%), and reduced the number of muscle larvae (Enterocin M-39.6%, E. faecium CCM8558-55.7%, Durancin-like-15%, E. durans ED26E/7-36.3%). The direct effect of enterocins on Trichinella fecundity was documented by an in vitro test in which Durancin-like showed a comparable reducing effect to Enterocin M (40-60%) in contrast to the ex vivo test. The reducing activity of T.spiralis infection induced by Enterocin M was comparable to its strain E. faecium CCM8558; Durancin-like showed lower antiparasitic activity than its producer E. durans ED26E/7.

Lactiplantibacillus plantarum ZDY2013 Inhibits the Development of Non-Alcoholic Fatty Liver Disease by Regulating the Intestinal Microbiota and Modulating the PI3K/Akt Pathway

Non-alcoholic fatty liver disease (NAFLD) is a common chronic hepatic condition whose impact on human health is increasingly significant. The imbalance of the gut microbiome, linked to insulin resistance, heightened intestinal permeability, and pro-inflammatory reactions, may be the linchpin in the development of NAFLD. In our research, the impact of Lactiplantibacillus plantarum ZDY2013 administration for 12 weeks on gut microbiota dysbiosis induced by a high-fat, high-fructose, high-cholesterol (FHHC) diet in male C57BL/6n mice was investigated. Research results presented that the intervention of L. plantarum ZDY2013 in mice fed with the FHHC diet could restore their liver function and regulate oxidative stress. Compared to mice in the model group, the intervention of L. plantarum ZDY2013 significantly regulated the gut microbiota, inhibited the LPS/NF-κB pathway, and led to a lower level of colonic inflammation in the mice administered with L. plantarum ZDY2013. It also improved insulin resistance to regulate the PI3K/Akt pathway and lipid metabolism, thereby resulting in reduced fat accumulation in the liver. The above results suggest that the intervention of L. plantarum ZDY2013 can hinder the progression of diet-induced NAFLD by reducing inflammation to regulate the PI3K/Akt pathway and regulating gut microbiota disturbance.

The anticancer effect of potential probiotic L. fermentum and L. plantarum in combination with 5-fluorouracil on colorectal cancer cells

5-Fluorouracil (5-FU) is an effective chemotherapy drug in the treatment of colorectal cancer (CRC). However, auxiliary or alternative therapies must be sought due to its resistance and potential side effects. Certain probiotic metabolites exhibit anticancer properties. In this study evaluated the anticancer and potential therapeutic activities of cell extracts potential probiotic strains, Limosilactobacillus fermentum and Lactiplantibacillus plantarum isolated from the mule milk and the standard probiotic strain Lacticaseibacillus rhamnosus GG (LGG) against the human colon cancer cell line (HT-29) and the normal cell line (HEK-293) alone or in combination with 5-FU. In this study, L. plantarum and L. fermentum, which were isolated from mule milk, were identified using biochemical and molecular methods. Their probiotic properties were investigated in vitro and compared with the standard probiotic strain of the species L. rhamnosus GG. The MTT assay, acridine orange/ethidium bromide (AO/EB) fluorescent staining, and flow cytometry were employed to measure the viability of cell lines, cell apoptosis, and production rates of Th17 cytokines, respectively. The results demonstrated that the combination of lactobacilli cell extracts and 5-FU decreased cell viability and induced apoptosis in HT-29 cells. Furthermore, this combination protected HEK-293 cells from the cytotoxic effects of 5-FU, enhancing their viability and reducing apoptosis. Moreover, the combination treatment led to an increase in the levels of IL-17A, IFN-γ, and TNF-α, which can enhance anti-tumor immunity. In conclusion, the cell extracts of the lactobacilli strains probably can act as a potential complementary anticancer therapy.

Geroprotective potential of microbiome modulators in the Caenorhabditis elegans model

Aging is associated with cellular and physiological changes, which significantly reduce the quality of life and increase the risk for disease. Geroprotectors improve lifespan and slow the progression of detrimental aging-related changes such as immune system senescence, mitochondrial dysfunction, and dysregulated nutrient sensing and metabolism. Emerging evidence suggests that gut microbiota dysbiosis is a hallmark of aging-related diseases and microbiome modulators, such as probiotics (live bacteria) or postbiotics (non-viable bacteria/bacterial byproducts) may be promising geroprotectors. However, because they are strain-specific, the geroprotective effects of probiotics and postbiotics remain poorly understood and understudied. Drosophila melanogaster, Caenorhabditis elegans, and rodents are well-validated preclinical models for studying lifespan and the role of probiotics and/or postbiotics, but each have their limitations, including cost and their translation to human aging biology. C. elegans is an excellent model for large-scale screening to determine the geroprotective potential of drugs or probiotics/postbiotics due to its short lifecycle, easy maintenance, low cost, and homology to humans. The purpose of this article is to review the geroprotective effects of microbiome modulators and their future scope, using C. elegans as a model. The proposed geroprotective mechanisms of these probiotics and postbiotics include delaying immune system senescence, preventing or reducing mitochondrial dysfunction, and regulating food intake (dietary restriction) and metabolism. More studies are warranted to understand the geroprotective potential of probiotics and postbiotics, as well as other microbiome modulators, like prebiotics and fermented foods, and use them to develop effective therapeutics to extend lifespan and reduce the risk of debilitating aging-related diseases.

Dissecting the Genetic Basis of the Technological, Functional, and Safety Characteristics of Lacticaseibacillus paracasei SRX10

Nonstarter lactic acid bacteria (NSLAB) are major contributors to the unique characteristics (e.g., aroma, flavor, texture) of dairy and nondairy fermented products. Lc. paracasei SRX10 is an NSLAB strain originally isolated from a traditional Greek cheese and previously shown to exhibit favorable biotechnological characteristics. More specifically, the strain showed tolerance to simulated gastrointestinal conditions, exopolysaccharide (EPS) biosynthetic capacity, and lack of hemolytic activity and was used in the production of yoghurt and feta cheese with distinct organoleptic characteristics. The aim of the present study was to investigate these traits at the genome level through whole-genome sequencing (WGS), annotation, and comparative genomics. Functional annotation of the genome revealed that Lc. paracasei SRX10 can utilize different carbon sources, leading to the generation of flavor compounds, including lactic acid, acetate, ethanol, and acetoin. Similarly, full clusters for fatty acid biosynthesis, protein and peptide degradation, as well as genes related to survival under extreme temperatures, osmotic shock, and oxidative stress were annotated. Importantly, no transferable antibiotic resistance genes or virulence factors were identified. Finally, strain-specific primers based on genome-wide polymorphisms were designed for the efficient and rapid identification of Lc. paracasei SRX10 via multiplex PCR in fermented products.

Proteolysis and therapeutic potential of bioactive peptides derived from Cheddar cheese

Cheddar cheese-derived bioactive peptides are considered a potential component of functional foods. A positive impact of bioactive peptides on diet-related chronic, non-communicable diseases, like obesity, cardiovascular diseases, and diabetes, has been observed. Bioactive peptides possess multifunctional therapeutic potentials, including antimicrobial, immunomodulatory, antioxidant, enzyme inhibitory effects, anti-thrombotic, and phyto-pathological activities against various toxic compounds. Peptides can regulate human immune, gastrointestinal, hormonal, and neurological responses, which play an integral role in the deterrence and treatment of certain diseases like cancer, osteoporosis, hypertension, and other health disorders, as described in the present review. This review summarizes the categories of the Cheddar cheese-derived bioactive peptides, their general characteristics, physiological functions, and possible applications in healthcare.

Bacteroides uniformis-induced perturbations in colonic microbiota and bile acid levels inhibit TH17 differentiation and ameliorate colitis developments

Inflammatory bowel disease (IBD) is associated with gut dysbiosis and can lead to colitis-associated malignancies. Bacteroides uniformis (Bu) regulates animal intestinal homeostasis; however, the mechanism by which it alleviates colitis in mice remains unknown. We investigated the effects of B. uniformis JCM5828 and its metabolites on female C57BL/6J mice with dextran sulfate sodium salt (DSS) induced colitis. Treatment with Bu considerably alleviated colitis progression and restored the mechanical and immune barrier protein expression. Additionally, Bu increased the abundance of the symbiotic bacteria Bifidobacterium and Lactobacillus vaginalis while decreasing that of pathogenic Escherichia-Shigella, and modulated intestinal bile acid metabolism. Bu largely regulated the expression of key regulatory proteins of the NF-κB and mitogen-activated protein kinase (MAPK) signaling pathways in colonic tissues and the differentiation of TH17 cells. However, Bu could not directly inhibit TH17 cell differentiation in vitro; it modulated the process in the lamina propria by participating in bile acid metabolism and regulating key metabolites (alpha-muricholic, hyodeoxycholic, and isolithocholic acid), thereby modulating the intestinal immune response. Our findings suggest that Bu or bile acid supplements are potential therapies for colitis and other diseases associated with intestinal barrier dysfunction.

Probiotic Properties, Safety Assessment, and Aroma-Generating Attributes of Some Lactic Acid Bacteria Isolated from Iranian Traditional Cheese

Artisanal cheeses are known as the source of beneficial lactic acid bacteria (LAB). Therefore, this study aimed to isolate and characterize LAB with different proteolytic activities from Iranian artisanal white cheeses. The isolates were classified into low, medium, and high proteolytic activity clusters via K-means clustering and identified as Lactiplantibacillus (Lpb.) pentosus L11, Lpb. plantarum L33, and Enterococcus faecium L13, respectively. Some safety tests (such as resistance to antibiotics, hemolytic activity, and biogenic amine production), probiotic properties (including cell surface hydrophobicity, auto/co-aggregation, and antibacterial activity), and production of volatile compounds were evaluated. These were non-hemolytic and non-biogenic amine producers, and showed no irregular antibiotic resistance. Lpb. plantarum L33 had the highest hydrophobicity (30.55%) and auto-aggregation (49.56%), and the highest co-aggregation was observed for Lpb. pentosus L11 with Staphylococcus aureus (61.51%). The isolates also showed a remarkable antibacterial effect against pathogenic bacteria. Moreover, Lpb. pentosus L11 and Lpb. plantarum L33 with low and medium proteolytic activity produced a wider range of volatile compounds in milk compared to the strain with a high proteolytic effect. The results showed that a probiotic strain with low or medium proteolytic activity could improve the flavor characteristics of fermented milk.

Probiotic with gluten reduction property and its encapsulation in synbiotic aloe vera gel-alginate capsules with banana powder as prebiotic

This study aims to hydrolyze the immunogenic gluten peptides by probiotic bacteria, Lactococcus lactis G01. It was isolated from curd and isolation was done based on ability to hydrolyze gluten. It was also tested for probiotic properties such as survival in gastric juice, bile salts, acid resistance, antibiotic sensitivity, antioxidant potential, sodium chloride tolerance, and antimicrobial activity. Lactococcus lactis G01 exhibited potential probiotic properties also, hence it was selected for microencapsulation. Probiotic was encapsulated in sodium alginate beads using banana powder as prebiotic and aloe vera as the adsorbent. The bead morphology was studied using scanning electron microscopy and transmission electron microscopy. The chemical composition of the bead was confirmed by FTIR. It was observed that 99% of the encapsulated probiotic cells were released into the simulated intestinal fluid in 90 min. Storage study was conducted for encapsulated probiotic and after four weeks of storage, the probiotic count in microcapsules was 7.82 log10 CFU/g. The formulated synbiotic capsules are suggested to incorporate in porridge for celiac patients since the probiotic has gluten reduction property.

Graphical abstract

Genetic and Probiotic Characteristics of Urolithin A Producing Enterococcus faecium FUA027

Enterococcus faecium FUA027 transforms ellagic acid (EA) to urolithin A (UA), which makes it a potential application in the preparation of UA by industrial fermentation. Here, the genetic and probiotic characteristics of E. faecium FUA027 were evaluated through whole-genome sequence analysis and phenotypic assays. The chromosome size of this strain was 2,718,096 bp, with a GC content of 38.27%. The whole-genome analysis revealed that the genome contained 18 antibiotic resistance genes and seven putative virulence factor genes. E. faecium FUA027 does not contain plasmids and mobile genetic elements (MGEs), and so the transmissibility of antibiotic resistance genes or putative virulence factors should not occur. Phenotypic testing further indicated that E. faecium FUA027 is sensitive to clinically relevant antibiotics. In addition, this bacterium exhibited no hemolytic activity, no biogenic amine production, and could significantly inhibit the growth of the quality control strain. In vitro viability was >60% in all simulated gastrointestinal environments, with good antioxidant activity. The study results suggest that E. faecium FUA027 has the potential to be used in industrial fermentation for the production of urolithin A.

Investigating the Probiotic Properties and Antimicrobial Activity of Lactic Acid Bacteria Isolated from an Iranian Fermented Dairy Product, Kashk

In the present study, kashk samples were collected from two regions of Iran, the Fars (Abadeh) and Razavi Khorasan (Kalat) provinces. Fifteen bacteria were isolated and physiological and biochemical assays were performed. After identification to the genus level, eight isolates were identified as lactic acid bacteria (LAB) and subjected to molecular identification and probiotic properties assays. The results revealed that the isolates were Enterococcus faecium KKP 3772 (KF1), Enterococcus faecium C1 (KF2), Pediococcus pentosaceus H11 (KF3), Pediococcus pentosaceus VNK-1 (KK4), Lactococcus lactis RSg (KK1), Enterococcus faecalis P190052 (KK2), Enterococcus mundtii CECT972T (KK3), and Lactiplantibacillus plantarum PM411 (KK5). Only the numbers of L. lactis RSg (KK1) and Lpb. Plantarum PM411 (KK5) decreased to below 9 Log CFU/mL after acidic conditions (pH = 3) and showed weak antibacterial activity. Enterococcus mundtii CECT972T (KK3) and E. faecium C1(KF2) were highly susceptible to bile salts, while P. pentosaceus VNK-1 (KK4) and P. pentosaceus H11 (KF3) showed the highest resistance. All of the isolates were resistant to tetracycline and sensitive to chloramphenicol and gentamicin. The antimicrobial activity of P. pentosaceus VNK-1 (KK4) and P. pentosaceus H11 (KF3) was higher than other isolates and consequently, their inhibition zones were larger. The adhesion capabilities of LAB isolates to intestinal epithelial cells were evaluated by examining the auto-aggregation factor and cell surface hydrophobicity. The highest and lowest cell surface hydrophobicity and auto-aggregation were obtained from P. pentosaceus VNK-1 (KK4) and E. mundtii CECT972T (KK3), respectively. In general, P. pentosaceus VNK-1 (KK4) and P. pentosaceus H11 (KF3) have shown better probiotic properties as compared to other isolates.

Lactic acid bacteria isolated from Chinese traditional fermented milk as novel probiotic strains and their potential therapeutic applications

Lactic acid bacteria (LAB) are believed to have health-promoting properties to the host and can be used in therapeutics interventions; intriguingly, they have the property to produce bio-preservatives substances. Therefore, this study aimed to mine probiotics and evaluate their safety, functional properties, and cholesterol-lowering capability. Seven potential probiotic strains were compared from 56 LAB strains isolated from traditional Chinese fermented milk. The results showed that all tested strains are tolerant to gastric acidity (45.5-83.26) and bile salts (11.92-92.91%) and have antibacterial activity against Staphylococcus aureus ATCC25923 and Escherichia coli ATCC25922. Likewise, it lowered the cholesterol levels in vitro by live cells (26.57-45.76%) and dead cells (29.53-50.97%) with remarkable aggregation ability (13.8-43.71%). Antioxidant properties and produce short chain fatty acids (SCFAs) were strain-dependent features. Upon assessment of the safety, Enterococcus faecium NWAFU-BIO-AS14 exhibited virulence factors genes (VFs) of (mur-2ed, odc, and tet(K)) and + hemolysis activity. While Enterococcus faecium NWAFU-BIO-A-B24 and Limosilactobacillus fermentum NWAFU-BIO-B-S6 have VFs of (odc, vanC2, and ant(6)-Ia). Limosilactobacillus fermentum NWAFU-BIO-D-B2 has only (odc). Thus, they are not considered as safe probiotics. In contrast, Lactiplantibacillus plantarum NWAFU-BIO-BS29, Companilactobacillus crustorum NWAFU-BIO-AS16, and Lactobacillus gallinarum NWAFU-BIO-D-S7 are the safest and best strains, respectively, due to the absence of 16 VFs and their sensitivity to antibiotics such as kanamycin, erythromycin, tetracycline, gentamycin, vancomycin, streptomycin, chloramphenicol, and ampicillin. Accordingly, these strains have a high potentiality to be used as starter cultures or safely applied as perfect probiotics in functionals food and feed.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-022-03403-z.

Probiotic of Lactiplantibacillus plantarum NWAFU-BIO-BS29 Isolated from Chinese Traditional Fermented Milk and Its Potential Therapeutic Applications Based on Gut Microbiota Regulation

Lactic acid bacteria are one of the bioresources that can promote the host's health and have potential therapeutic applications. This study aimed to evaluate the probiotic properties of novel Lactiplantibacillus plantarum NWAFU-BISO-BS29 isolated in vitro from traditional Chinese fermented milk, assess its safety, and study its interaction with the gut microbiota using a BALB/c mouse model. The findings reveal that this strain had a high tolerance to gastric acidity (64.4%) and bile salts (19.83-87.92%) with remarkable auto-aggregation and co-aggregation abilities (33.01-83.96%), respectively. Furthermore, it lowered the cholesterol levels in dead cells (44.02%) and live cells (34.95%) and produced short-chain fatty acids (SCFAs). Likewise, it showed good antioxidant properties and strong antipathogen activity against Escherichia coli and Staphylococcus aureus with inhibition zones at 21 and 25 mm, respectively. The safety assessment results indicate that all of the virulence factor genes were not detected in the whole DNA; additionally, no hemolysis or resistance to antibiotics commonly used in food and feed was observed. Interestingly, the 16S rRNA gene sequencing of the mouse gut microbiota showed a marked alteration in the microbial composition of the administrated group, with a noticeable increase in Firmicutes, Patescibacteria, Campylobacterota, Deferribacterota, Proteobacteria, and Cyanobacteria at the phylum level. The modulation of gut microbial diversity significantly improved the production of SCFCs due to the abundance of lactobacillus genera, which was consistent with the functional gene predictive analysis and is believed to have health-promoting properties. Based on these results, our novel strain is considered a safe and good probiotic and could hold high potential to be used as a starter culture or to safely supplement functional foods as a probiotic and may provide new insights into therapeutic interventions.

Honeybee-associated lactic acid bacteria and their probiotic potential for human use

This study aims to identify lactic acid bacteria (LAB) isolated from honeybees (Apis mellifera workers and larvae) in detail and to determine their functional probiotic properties. A total of 11 strains were classified based on morphological and biochemical characteristics. Preliminary probiotic properties of strains, that were molecularly identified using 16 S rRNA, such as antimicrobial activity, tolerance to digestive conditions, aggregation ability, were investigated. The antimicrobial properties of strains were tested against a wide range of human pathogens. All strains that showed γ-hemolysis and did not contain bacteriophages were considered safe. The strains' survivability checked for 0.3% bile and 3.0-7.8 pH contents was promising. The highest autoaggregation ranged from 14.7 to 30.76% after 4 h. Tested LAB strains markedly exhibited coaggregation with Listeria monocytogenes and Escherichia coli. According to the results, tested bacteria showed significant antagonistic effects against pathogens, and positive probiotic characteristics compatible with in vitro gastrointestinal tract conditions. The results suggest that Apis mellifera LAB symbionts may have a probiotic potential, and be effective and safe candidates for human use. This study provides an addition to the development of the current knowledge by defining in detail honeybee-associated bacteria and determining their probiotic potential.

Lactic Acid Bacteria in Raw-Milk Cheeses: From Starter Cultures to Probiotic Functions

Traditional cheeses produced from raw milk exhibit a complex microbiota, characterized by a sequence of different microorganisms from milk coagulation and throughout maturation. Lactic acid bacteria (LAB) play an essential role in traditional cheese making, either as starter cultures that cause the rapid acidification of milk or as secondary microbiota that play an important role during cheese ripening. The enzymes produced by such dynamic LAB communities in raw milk are crucial, since they support proteolysis and lipolysis as chief drivers of flavor and texture of cheese. Recently, several LAB species have been characterized and used as probiotics that successfully promote human health. This review highlights the latest trends encompassing LAB acting in traditional raw milk cheeses (from cow, sheep, and goat milk), and their potential as probiotics and producers of bioactive compounds with health-promoting effects.

Cervicovaginal microbiota isolated from healthy women exhibit probiotic properties and antimicrobial activity against pathogens isolated from cervical cancer patients

Abnormal cervicovaginal microbiota play an important role in HPV persistence and progression to cervical cancer. The present study aimed at isolating and identifying potential probiotics from vaginal swabs of healthy women and evaluating their activity against vaginal pathogens isolated from cervical cancer patients. Based on probiotic, acid-bile tolerance and antimicrobial properties, 13 lactic acid bacteria (LAB) from the healthy group were identified by MALDI TOF MS (Matrix Assisted Laser Desorption and Ionisation, Time Of Flight Mass Spectrometry). Among these, four strains, Lactobacillus gasseri P36Mops, Limosilactobacillus fermentum P37Mws, Lactobacillus delbrueckii P31Mcs and Enterococcus faecium P26Mcm, exhibited significant antimicrobial activity against 8 vaginal pathogens (Staphylococcus haemolyticus P41Tcs, Escherichia coli P30Tcs, E. coli P79Bcm, Enterococus faecalis P29Mops, E. faecalis P50Tws, E. faecalis P68Tcb, S. haemolyticus P48Bcb and S. haemolyticus P58Bcb) isolated from precancerous and cervical cancer patients. 16S rRNA sequencing of four potential probiotics revealed congruency with the MALDI-TOF MS identification and phylogenetic analysis showed genetic relationship with previously reported LAB strains. The selected LAB showed strain specific hydrophobicity (35.88-56.70%), auto-aggregation (35.26-61.39%) and antibiotic susceptibility. Interestingly, L. gasseri P36Mops was resistant to five standard antibiotics routinely used against urogenital or vaginal infections. LCMS (Liquid Chromatography Mass Spectrometry) analyses of the CFS (cell-free supernatant) of the four potential probiotics revealed the presence of metabolites such as N-(1-deoxy-1-fructosyl)valine, hygroline, acetoxy-2-hydroxy-16-heptadecen-4-one, avocadyne 4-acetate, avocadyne 2-acetate, taraxinic acid glucosyl ester, 6-hydroxypentadecanedioic acid, with reported antimicrobial activity. The overall data suggest the bio-therapeutic potential of the identified vaginal probiotics against cervical cancer-associated pathogens.

Antioxidant Mechanism of Lactiplantibacillus plantarum KM1 Under H2O2 Stress by Proteomics Analysis

Lactiplantibacillus plantarum KM1 was screened from natural fermented products, which had probiotic properties and antioxidant function. The survival rate of L. plantarum KM1 was 78.26% at 5 mM H₂O₂. In this study, the antioxidant mechanism of L. plantarum KM1 was deeply analyzed by using the proteomics method. The results demonstrated that a total of 112 differentially expressed proteins (DEPs) were screened, of which, 31 DEPs were upregulated and 81 were downregulated. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis indicated that DEPs participated in various metabolic pathways such as pyruvate metabolism, carbon metabolism, trichloroacetic acid cycle, amino acid metabolism, and microbial metabolism in diverse environments. These metabolic pathways were related to oxidative stress caused by H₂O₂ in L. plantarum KM1. Therefore, the antioxidant mechanism of L. plantarum KM1 under H₂O₂ stress provided a theoretical basis for its use as a potential natural antioxidant.

Isolation and characterization of exopolysaccharide derived from Lacticaseibacillus paracasei AS20(1) with probiotic potential and evaluation of its antibacterial activity

This study was done to find exopolysaccharide (EPS)-producing lactic acid bacteria (LAB) against foodborne pathogens. Isolated LAB were screened to find the ones with the ability to produce antibacterial EPS against foodborne pathogens. Among tested EPSs, EPS of AS20(1) isolate showed inhibitory effects on the growth of Listeria monocytogenes (MIC = 0·935 mg ml^-1 , MBC = 0·935 mg ml^-1 ), Yersinia enterocolitica (MIC = 12·5 mg ml^-1 , MBC = 50 mg ml^-1 ) and Bacillus cereus (MIC = 6·25 mg ml^-1 , MBC = 12·5 mg ml^-1 ). According to 16S rRNA sequencing, AS20(1) showed the closest similarity to Lacticaseibacillus paracasei (100%). This antibacterial EPS showed negligible toxicity (4·4%-5·2%) against red blood cells. Lacticaseibacillus paracasei AS20(1) showed probiotic properties, including high acid resistance, hydrophobicity (47·5%), autoaggregation and coaggregation with foodborne pathogens. Also, L. paracasei AS20(1) showed no haemolysis activity and antibiotic resistance. Characterization of antibacterial EPS revealed that it is a heteropolysaccharide with various functional groups, amorphous structure, and smooth surface, sheet and compact structure, which can be suitable for food packaging. L. paracasei AS20(1) and its antimicrobial EPS can be used to make functional food.

Cyclo(L-Leucyl-L-Prolyl) from Lactobacillus coryniformis BCH-4 inhibits the proliferation of Aspergillus flavus: an in vitro to in silico approach

Fungal spoilage led to a considerable economic loss of foodstuff which ultimately affects public health due to mycotoxins production. Moreover, the consumption of commercial antifungal drugs creates side effects and develops antifungal resistance. To overcome these challenges, the current work was aimed to investigate novel antifungal cyclic dipeptide (CDP) from Lactobacillus coryniformis (Loigolactobacillus coryniformis) BCH-4. CDPs have flexible, cyclic, and stable conformation. The proline-based CDPs provide additional structural compatibility and bio-functional values. Keeping in view, high-performance liquid chromatography (HPLC) was performed to explore cyclo(L-Leu-L-Pro) from L. coryniformis BCH-4. The HPLC detected concentration (135 ± 7.07 mg/mL) exhibited in vitro antifungal activity of 5.66 ± 0.57 mm (inhibitory zone) against Aspergillus flavus. Based on these results, cyclo(L-Leu-L-Pro) was used as a bioprotectant for selected food samples (grapes, lemon, cashew nuts, and almonds). A significant impact of cyclo(L-Leu-L-Pro) was observed in contrast with MRS broth (control) and cell-free supernatant. In silico molecular docking analysis of this CDP was carried out against FAD glucose dehydrogenase, dihydrofolate reductase, and urate oxidase of A. flavus as target proteins. Among these proteins, FAD glucose dehydrogenase exerted strong interactions with cyclo(L-Leu-L-Pro) having S-score of  - 8.21. The results evaluated that the detected CDP has strong interactions with selected proteins, causing excellent growth inhibition of A. flavus. Therefore, cyclo(L-Leu-L-Pro) could be used as a potent bioprotectant against food-borne pathogenic fungi.

Probiotic microbes: Are their anti-melanogenicity and longevity promoting activities closely linked through the major "pathogenic" kinase PAK1?

PAK1-deficient mutant of C. elegans lives 60% longer than the wild-type. Interestingly, PAK1-deficient mutant of melanocytes produces less melanin (only a half compared with the wild-type) in the presence of either serum (PDGF) or α-MSH (alpha-melanocyte stimulating hormone). These observations indicate that the major "pathogenic" kinase PAK1 is responsible for both shortening the healthy lifespan, and PDGF/α-MSH-dependent melanogenesis. For screening of PAK1-blocking probiotic bacteria or their products, their anti-melanogenic as well as longevity promoting properties were examined. Recently it was found that C. elegans fed with Lactobacillus rhamnosus in Xinjiang cheese lives 40% longer than the worm fed with the standard E. coli. Interestingly, a Chinese traditional medicine called "ChiBai" fermented with the Lactobacillus rhamnosus also inhibited the α-MSH-induced melanogenesis, and this bacteria itself produces butyric acid that blocks the oncogenic HDAC (histone deacetylase)-PAK1 signaling pathway. These findings strongly suggest, if not proven, that anti-melanogenic activity of Lactobacillus and many other probiotic bacteria might serve as a reliable indicator for their longevity promoting activity. In this context, a popular Japanese Lactobacillus-fermented milk drink called "Calpis", developed a century ago, and recently proven to inhibit the melanogenesis by suppressing the PAK1-dependent tyrosinase gene expression, may potentially prolong our healthy lifespan.

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.

Weissella confusa CGMCC 19,308 Strain Protects Against Oxidative Stress, Increases Lifespan, and Bacterial Disease Resistance in Caenorhabditis elegans

The aim of this study was to investigate the antioxidant activity of Weissella confusa CGMCC 19,308 and its influence on longevity and host defense against Salmonella Typhimurium of Caenorhabditis elegans. The CFCS (cell-free culture supernatant) of W. confusa CGMCC 19,308 possessed DPPH radicals, hydroxyl radicals, and superoxide anion scavenging activity. The lifespan of the C. elegans fed W. confusa CGMCC 19,308 was significantly (p < 0.001) longer than that of worms fed Escherichia coli OP50. Moreover, worms fed W. confusa CGMCC 19,308 were more resistant to oxidative stress induced by hydrogen peroxide and S. Typhimurium infection. RNA-seq analysis showed that the most significantly differentially expressed genes (DEGs) in C. elegans fed with W. confusa CGMCC 19,308 were mainly col genes (col-43, col-2, col-40, col-155, col-37), glutathione-S-transferase (GST)-related genes (gst-44, gst-9, gst-17, gst-18, gstk-2), cnc-9 (immune-related gene), and sod-5 (superoxide dismutase). These results indicated that cuticle collagen synthesis, immunity, and antioxidant defense (AOD) system of C. elegans were affected after being fed with W. confusa CGMCC 19,308 instead of E. coli OP50. Our study suggested W. confusa CGMCC 19,308 had the antioxidant activity and could prolong lifespan and enhance the host defense against S. Typhimurium of C. elegans. This study provided new evidences for the W. confusa CGMCC 19,308 as a potential probiotic candidate for anti-aging and anti-bacterial infection.

Probiotics in the dairy industry-Advances and opportunities

The past two decades have witnessed a global surge in the application of probiotics as functional ingredients in food, animal feed, and pharmaceutical products. Among food industries, the dairy industry is the largest sector where probiotics are employed in a number of dairy products including sour/fermented milk, yogurt, cheese, butter/cream, ice cream, and infant formula. These probiotics are either used as starter culture alone or in combination with traditional starters, or incorporated into dairy products following fermentation, where their presence imparts many functional characteristics to the product (for instance, improved aroma, taste, and textural characteristics), in addition to conferring many health-promoting properties. However, there are still many challenges related to the stability and functionality of probiotics in dairy products. This review highlights the advances, opportunities, and challenges of application of probiotics in dairy industries. Benefits imparted by probiotics to dairy products including their role in physicochemical characteristics and nutritional properties (clinical and functional perspective) are also discussed. We transcend the traditional concept of the application of probiotics in dairy products and discuss paraprobiotics and postbiotics as a newly emerged concept in the field of probiotics in a particular relation to the dairy industry. Some potential applications of paraprobiotics and postbiotics in dairy products as functional ingredients for the development of functional dairy products with health-promoting properties are briefly elucidated.

Nicotinamide Mononucleotide Combined With Lactobacillus fermentum TKSN041 Reduces the Photoaging Damage in Murine Skin by Activating AMPK Signaling Pathway

Long-term exposure to UVB (280-320 nm) can cause oxidative skin damage, inflammatory injury, and skin cancer. Research on nicotinamide mononucleotide (NMN) and lactic acid bacteria (LAB) with regard to antioxidation, anti-inflammation, and prevention of other age-related diseases has received increasing attention. In the present study, the in vitro antioxidant analysis showed that NMN combined with Lactobacillus fermentum TKSN041 (L. fermentum TKSN041) has a high scavenging ability on hydroxyl (OH), 2, 2'-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) diammonium salt (ABTS) and 1, 1-diphenyl-2-picrylhydrazyl (DPPH), and it also possess a good total antioxidant capacity. The animal experimental results show that NMN combined with LAB maintained normal liver morphology of mice and reduced pathological damage to murine skin. NMN combined with LAB significantly increased the serum levels of total superoxide dismutase (T-SOD), catalase (CAT), and interleukin (IL)-10, but reduced the levels of malondialdehyde, advanced glycation end products, tumor necrosis factor (TNF)-α, and IL-6. NMN combined with LAB increased T-SOD, CAT, IL-10, Na⁺-K⁺-ATPase, and NAD⁺ levels in the skin, but reduced TNF-α level in the skin. NMN combined with LAB increased the mRNA expression levels of SOD1, CAT, glutathione (GSH), inhibitor of NF-κB (IκB-α), IL-10, AMP-activated protein kinase (AMPK), adaptor protein, phosphotyros ineinteraction, PH domain and leucine zipper containing 1 (APPL1), peroxisome proliferator-activated receptor γ co-activator-1α (PGC-1α), and forkhead transcription factor O (FOXO) in the skin and liver, but decreased the mRNA expression levels of nuclear factor (NF)-κBp65, TNF-α, IL-6, and rapamycin target protein (mTOR). NMN combined with LAB increased the protein expression levels of AMPK, IκB-α, SOD1, and CAT in the skin tissues and reduced protein expression of NF-κBp65. NMN combined with L. fermentum TKSN041 improved murine skin damage caused by UVB irradiation, and the protective mechanism may be related to activation of the AMPK signaling pathway. The results of this study are expected to provide a reference for preventing and the treating skin photoaging.

Engineering management of starter cultures in study of temperature of fermentation of sour-milk drink with apiproducts

The article considers the solution of problematic issues of engineering management of poly fermentation in the study of fermentation temperature of sour-milk drink with apiproducts. In the development of fermented dairy products, the components that are part of them, changes in their composition, and properties in the interconnection are considered as a technological system. The authors took into account that food technologies based on the use of the pure culture of one microorganism are limited by the capabilities of its fermentation system systems, the ultimate goal may not be achieved even by changing the conditions and parameters of cultivation. To successfully carry out fermentation processes in the technological system, a combination of cultures, associations of microorganisms with a wide range of fermentation products in contrast to one culture is promising to use. All experimental samples on a set of indicators prevailed control ones. The leader was a sample fermented with yeast with an equal ratio of cultures at a temperature of 38 – 40 °C. The authors found that the set of indicators of finished products for the production of sour-milk drinks with a complex of apiproducts, it is necessary to choose a three-strain poly fermentation product with a congruent ratio of cultures and set optimal fermentation regimes 39 ±1ºC for 5.0 ±0.3 hours.

Development of an innovative methodology combining chemical fractionation and in vivo analysis to investigate the biological properties of cheese

With the ever-increasing human lifespan, age-related affections have become a public health issue. The health sector is looking for new bioactive compounds to respond to this demand. The unexplored microbial biodiversity and its metabolites represent a major source of innovative bioactive molecules with health potential. Fermented foods, such as raw-milk cheese, have already been investigated for their rich microbial environment, especially for their organoleptic qualities. But studies remain limited regarding their effects on health and few metabolites of microbial origin have been identified. An efficient methodology was developed in this study to investigate the biological effect of raw-milk cheese, combining a chemical fractionation, to isolate the most metabolites from the cheese matrix, and an in vivo biological test using Caenorhabditis elegans. C. elegans was brought into contact with cheese extracts, obtained by means of chemical fractionation, and with freeze-dried whole cheese by supplementing the nematode growth medium. A longevity assay was performed to evaluate the effects of the extracts on the worms. Our results demonstrate the feasibility of the method developed to bring the worms into contact of the cheese extracts. The evaluation of the effects of the extracts on the longevity was possible. Some extracts showed a beneficial effect as extract W70 for example, obtained with water, which increases the mean lifespan by 16% and extends the longevity by 73% (p < 0.0001).

Molecular detection, phylogenetic analysis, and antibacterial performance of lactic acid bacteria isolated from traditional cheeses, North-West Iran

Lactic acid bacteria (LAB) are candidate probiotic bacteria that can provide health benefits when delivered via functional foods. The purpose of this study was to isolate and characterize LAB from traditional cheeses consumed in north-west regions of Iran. A number of sixty traditional cheeses samples were collected and initially screened as LAB using biochemical and molecular methods. A fragment of 1,540 bp in size of 16s rRNA gene was amplified from 70 bacterial isolates. Restriction fragment length polymorphism (RFLP) was employed to differentiate LAB isolates. LAB isolates generated three different RFLP patterns using HinfI restriction enzyme. Phylogenetic analysis revealed that LAB isolates belonged to three genera including Enterococcus, Lactobacillus, and Lactococcus. Most of the isolated LAB strains belonged to Enterococcus spp. The antimicrobial performance of eight LAB isolates with different RFLP patterns ranged from 6.72 to 14.00 mm. It was concluded that molecular characterization of LAB strains in traditional cheeses will enhance our understanding of traditional food microbiota and will help to find bacterial strains with probiotic potential with great benefit both in health and industry.

In Vitro Antimicrobial and Antioxidant Activities of Lactobacillus coryniformis BCH-4 Bioactive Compounds and Determination of their Bioprotective Effects on Nutritional Components of Maize (Zea mays L.)

Lactic acid bacteria (LAB) can synthesize antimicrobial compounds (AMCs) with nutritional and bioprotective properties in crops and food products. In the current study, AMCs of Lactobacillus coryniformis BCH-4 were evaluated to control fungal spoilage in maize grains. On maize grains treated with 75%-100% (v/v) concentrated AMCs, no fungal growth was observed even after 72 h of Aspergillus flavus inoculation. Proximate analysis of treatments A1 (raw grains), A2 (A. flavus inoculated grains) and A3 (A. flavus + AMCs inoculated grains) revealed that moisture was significantly (p ≤ 0.05) high in A2 than A3 and A1. Meanwhile, protein, fat, fiber and ash contents were significantly decreased in A2 compared to A1 and A3. Moreover, β-carotene contents were not statistically different between A1 and A3, while in A2 it was significantly decreased. HPLC analysis revealed the presence of 2-oxopropanoic acid, 2-hydroxypropane-1,2,3-tricarboxylic acid, 2-hydroxybutanedioic acid, 2-hydroxypropanoic acid, propanedioic acid and butanedioic acid, which also showed antifungal activity against Aspergillus flavus. FTIR spectroscopy revealed the presence of hydroxyl, carbonyl and ester-groups along with organic and fatty acids, thereby indicating their participation in inhibitory action. Furthermore, the AMCs were found to be a good alternative to chemical preservatives, thereby not only preserving the nutritive qualities but increasing the shelf life as well.

Functional probiotics of lactic acid bacteria from Hu sheep milk

Background

Probiotics are being considered as valuable microorganisms related to human health. Hu sheep is referred as one of the important sheep breeds in China. Goat milk produced by Hu sheep is characterized with high nutritional value and hypoallergenic in nature. Particularly, this milk contains plenty of milk prebiotic and probiotic bacteria. This study was aimed to scrutinize more bacterial strains from Hu sheep milk with potential probiotic activity.

Results

Based on 16S rRNA sequence analysis, pool of forty bacterial strains were identified and evaluated their antimicrobial activities against Staphylococcus aureus, enterohemorrhagic Escherichia coli (EHEC), Salmonella typhimurium, Listeria monocytogenes enterotoxigenic E. coli (ETEC) and Aeromonas caviae. Four out of these isolated strains demonstrated their efficient bacteriostatic ability and potential healthy properties. We also examined the safety aspects of these bacterial candidates including three Lactococcus lactis strains (named as HSM-1, HSM-10, and HSM-18) and one Leuconostoc lactis strain (HSM-14), and were further evaluated via in vitro tests, including antimicrobial activity, cell surface characteristics (hydrophobicity, co-aggregation, and self-aggregation), heat treatment, antibiotic susceptibility, simulated transport tolerance in the gastrointestinal tract, and acid/bile tolerance. The obtained results revealed that HSM-1, HSM-10, HSM-14, and HSM-18 showed high survival rate at different conditions for example low pH, presence of bovine bile and demonstrated high hydrophobicity. Moreover, HSM-14 had an advantage over other strains in terms of gastrointestinal tract tolerance, antimicrobial activities against pathogens, and these results were significantly better than other bacterial candidates.

Conclusion

Hu sheep milk as a source of exploration of potential lactic acid bacteria (LAB) probiotics open the new horizon of probiotics usage from unconventional milk sources. The selected LAB strains are excellent probiotic candidates which can be used for animal husbandry in the future. Rationale of the study was to utilize Hu sheep milk as a source of potential probiotic LABs. The study has contributed to the establishment of a complete bacterial resource pool by exploring the Hu sheep milk microflora.

Diversity and specificity of the bacterial community in Chinese horse milk cheese

The nutrition and flavor of cheese are generated by the microbial community. Thus, horse milk cheese with unique nutrition and flavor, an increasingly popular local cheese of the Xinjiang Uygur Autonomous Region of China, is considered to have diverse and specific bacterial community. To verify this hypothesis, horse, cow, and goat milk cheese samples produced under the same environmental conditions and manufacturing process were collected, and the 16S rRNA gene was targeted to determine the bacterial population size and community composition by real‐time quantitative PCR and high‐throughput sequencing. The bacterial community of horse milk cheese had a significantly larger bacterial population size, greater species richness, and a more diverse composition than those of cow and goat milk cheeses. Unlike the absolute dominance of Lactococcus and Streptococcus in cow and goat milk cheeses, Lactobacillus and Streptococcus dominated the bacterial community as the starter lactic acid bacteria in horse milk cheese. Additionally, horse milk cheese also contains a higher abundance of unclassified secondary bacteria and specific secondary bacteria (e.g., Psychrobacter, Sulfurisoma, Halomonas, and Brevibacterium) than cow and goat milk cheeses. These abundant, diverse, and specific starter lactic acid bacteria and secondary bacteria may generate unique nutrition and flavor of horse milk cheese.

Multivariate Analysis of Increase in Life Span of Caenorhabditis elegans Through Intestinal Colonization by Indigenous Probiotic Strains

The present study aimed to analyze the colonization potential of indigenous probiotic strains and to assess their effects on physiology of Caenorhabditis elegans. The protective effect of probiotics was evaluated in terms of increase in life span of the worm through colonization in the intestine. A total of 15 probiotic cultures were evaluated for their effect on mean life span, pharyngeal pumping, and normal reproduction behavior in the worms. The chemotactic behavior in terms of binary choice index was also evaluated. The adherence and colonization of the intestine of the worm by probiotics were monitored at different time intervals by enumerating the microbial population and fluorescent microscopic observations. The survival analysis-based Kaplan-Meier method indicated that the probiotic cultures increased the survival probability as compared to control strain E. coli OP50. There was no effect of feeding probiotics on physiological responses of the worm such as pharyngeal pumping and reproduction. The principal component analysis (PCA) of the results indicated Lactobacillus plantarum K90 and L. paracasei CD4 as potential probiotics with binary choice index of 0.8 as food preference of C. elegans. The strains exhibit higher adherence and colonization in the gut of worms and increased the life span by 5 days as compared to control E. coli OP50. In conclusion, feeding with probiotic cultures is effective in extending the lifespan of C. elegans; however, the colonization ability differs among the strains.

Flavor quality evaluation system of Xinjiang milk knots by using SOM neural network and the fuzzy AHP

Self-made milk knots in Xinjiang Kazakh ethnic group were used as material to establish the quality assessment system of flavor quality. The fuzzy analytic hierarchy process based on the optimal consistency matrix was used to evaluate the quality of the samples qualitatively and quantitatively. Its result is consistent with the cluster analysis of the SOM neural network. The results showed that the milk knot samples of Altay had differences with the milk knot samples of Yili. The comprehensive evaluation system is feasible and can evaluate the quality of milk knot samples by flavor characteristics. This can provide a reference for further research on the origin of differences between two types of milk knot samples.

Combination of Probiotics and Salvia miltiorrhiza Polysaccharide Alleviates Hepatic Steatosis via Gut Microbiota Modulation and Insulin Resistance Improvement in High Fat-Induced NAFLD Mice

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) increases the risk of hepatocellular carcinoma, which is currently the leading cause of obesity-related cancer deaths in middle-aged men.

METHODS

Probiotics with lipid-lowering function were screened from the fecal microbiota of healthy adults. Polysaccharide from different sources was screened for improving insulin resistance. The combination of probiotics and Salvia miltiorrhiza polysaccharide (LBM) was investigated for alleviating hepatic steatosis.

RESULTS

First, Bifidobacterium bifidum V (BbV) and Lactobacillus plantarum X (LpX) were obtained from the fecal microbiota of healthy adults. Second, to improve insulin resistance, a Salvia miltiorrhiza Bunge polysaccharide showing good performance in reducing insulin resistance was obtained. The liver total cholesterol (TC) and total triglyceride (TG) levels and the serum levels of free fatty acid, alanine transaminase, aspartate transaminase, low density lipoprotein cholesterol, TG, and TC can be significantly reduced through supplementation with LpX-BbV (LB) in NAFLD mice. Interestingly, the function of the probiotic LB can be enhanced by S. miltiorrhiza Bunge polysaccharide. Furthermore, the gut microbiota was modulated by LpX-BbV+S. miltiorrhiza Bunge polysaccharide (LBM). The lipopolysaccharide concentration of the LBM group was decreased by 73.6% compared to the NAFLD group. Ultimately, the mRNA concentrations of the proinflammatory cytokines (tumor necrosis factor α, interleukin 1β [IL-1β], and IL-6) decreased with LB and LBM treatment.

CONCLUSION

The results of this this study indicate that the LBM combination can be used as a therapeutic for ameliorating NAFLD via modulating the gut microbiota and improving insulin resistance.

Caenorhabditis Elegans and Probiotics Interactions from a Prolongevity Perspective

Probiotics exert beneficial effects on host health through different mechanisms of action, such as production of antimicrobial substances, competition with pathogens, enhancement of host mucosal barrier integrity and immunomodulation. In the context of ageing, which is characterized by several physiological alterations leading to a low grade inflammatory status called inflammageing, evidences suggest a potential prolongevity role of probiotics. Unraveling the mechanisms underlying anti-ageing effects requires the use of simple model systems. To this respect, the nematode Caenorhabditis elegans represents a suitable model organism for the study of both host-microbe interactions and for ageing studies, because of conserved signaling pathways and host defense mechanisms involved in the regulation of its lifespan. Therefore, this review analyses the impact of probiotics on C. elegans age-related parameters, with particular emphasis on oxidative stress, immunity, inflammation and protection from pathogen infections. The picture emerging from our analysis highlights that several probiotic strains are able to exert anti-ageing effects in nematodes by acting on common molecular pathways, such as insulin/insulin-like growth factor-1 (IIS) and p38 mitogen-activated protein kinase (p38 MAPK). In this perspective, C. elegans appears to be advantageous for shedding light on key mechanisms involved in host prolongevity in response to probiotics supplementation.

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.