Fermented goat milk by selenium-enriched Lactobacillus paracasei alleviates depressive psychological disturbance.

Depression is a prevalent psychiatric disease with the characteristic of persistently gloomy mood. The treatment of depression with traditional therapeutic medications suffers from low efficacy and adverse side effects due to the extremely unpredictable courses and uneven responses to treatment. The goal of this paper was to investigate the preparation of selenium-enriched fermented goat milk and the potential mechanism of its intervention on the chronic unpredictable stress-induced depression mice model. The results showed that Se-Lactobacillus paracasei 20241 (Se-20241) significantly alleviated depressive behavior, reversed the upregulation of inflammatory factors, and attenuated glucocorticoid resistance. Meanwhile, the results showed a modulatory function on oxidative stress dysfunction in the liver, hippocampus, and prefrontal cortex. The change in abundance of Ileibacterium, Muribaculaceae, Turicibacter, Dubosiella, and Bifidobacterium was also modified. These results provided the theoretical groundwork for the development of psychoactive probiotic supplements for depressed patients and clarified the probable mechanism of Se-20241 for antidepressant impact on the CUMS model.

Investigation on Fermented Milk Quality after the Addition of Flaxseed Mucilage and the Use of Lactobacillus delbrueckii subsp. bulgaricus and Lactiplantibacillus plantarum AG9.

BACKGROUND: Flaxseed mucilage (FSM) is one of the healthy components of flaxseed. FSM is an example of a material that can be used in the food, cosmetic, and pharmaceutical industries due to its rheological properties. FSM consists mainly of two polysaccharides, arabinoxylan, and rhamnogalacturonan I, and it also contains protein components and minerals. The prospect of using FSM in food is due to its gelling, water binding, emulsifying, and foaming properties. In addition, valuable natural sources of phenolic compounds such as lignans, phenolic acids, flavonoids, phenylpropanoids, and tannins are partially extracted from flaxseed in FSM. These antioxidant components have pharmacological properties, including anti-diabetic, anti-hypertensive, immunomodulatory, anti-inflammatory and neuroprotective properties. A combination of FSM and lactobacilli in dairy foods can improve their functional properties. This study aimed to develop dairy products by adding of FSM and using two lactic acid bacteria (LAB). FSM (0.2%) was used as an ingredient to improve both the texture and antioxidant properties of the product. METHODS: Skim milk was fermented with 0.2% flaxseed mucilage using Lactobacillus delbrueckii subs. bulgaricus and the probiotic Lactiplantibacillus plantarum AG9. The finished fermented milk products were stored at 4 °C for 14 days. Quantitative chemical, textural, and antioxidant analyses were carried out. RESULTS: Adding 0.2% FSM to the dairy product stimulated the synthesis of lactic acid. FSM increased the viscosity and water-holding capacity of L. bulgaricus or L. bulgaricus/L. plantarum AG9 fermented milk products. Combining these starter strains with FSM promoted the formation of a hard, elastic, resilient casein matrix in the product. When only L. plantarum AG9 was used for the fermentation, the dairy product had a high syneresis and a low viscosity and firmness; such a product is inferior in textural characteristics to the variant with commercial L. bulgaricus. The addition of FSM improved the textural properties of this variant. The use of L. plantarum AG9 and FSM makes it possible to obtain a fermented milk product with the highest content of polyphenolic compounds, which have the highest antioxidant properties and stimulate lipase and α-glucosidase inhibitor synthesis. Combining of L. bulgaricus and L. plantarum AG9 in the starter (20% of the total mass of the starter) and adding of 0.2% FSM is the optimal combination for obtaining a dairy product with high textural and antioxidant properties. CONCLUSIONS: The physicochemical properties (viscosity, syneresis, water holding capacity, texture) and antioxidant properties of fermented milk were improved. In the future, as part of the work to investigate the functional properties of dairy products with FSM, studies will be conducted using in in vivo models.

Metabolomic analysis reveals Ligilactobacillus salivarius CCFM 1266 fermentation improves dairy product quality.

Previous studies have demonstrated that Ligilactobacillus salivarius CCFM 1266 exhibits anti-inflammatory properties and the capability to synthesize niacin. This study aimed to investigate the fermentative abilities of L. salivarius CCFM 1266 in fermented milk. Metabonomic analysis revealed that fermentation by L. salivarius CCFM 1266 altered volatile flavor compounds and metabolite profiles, including heptanal, nonanal, and increased niacin production. Genomic investigations confirmed that L. salivarius CCFM 1266 possess essential genes for the metabolism of fructose and mannose, affirming its proficiency in utilizing fructooligosaccharides and mannan oligosaccharides. The addition of fructooligosaccharides and mannan oligosaccharides during the fermentation process significantly facilitated the proliferation of L. salivarius CCFM 1266 in fermented milk, with growth exceeding 107 colony-forming units (CFU)/mL. This intervention not only augmented the microbial density but also modified the metabolite composition of fermented milk, resulting in an elevated presence of advantageous flavor compounds such as nonanal, 2,3-pentanedione, and 3-methyl-2-butanone. However, its influence on improving the texture of fermented milk was observed to be minimal. Co-fermentation of L. salivarius CCFM 1266 with commercial fermentation starters indicated that L. salivarius CCFM 1266 was compatible, similarly altering metabolite composition and increasing niacin content in fermented milk. In summary, the findings suggest that L. salivarius CCFM 1266 holds substantial promise as an adjunctive fermentation starter, capable of enhancing the nutritional diversity of fermented milk products.

Fermented Milk Containing Lacticaseibacillus rhamnosus SNU50430 Modulates Immune Responses and Gut Microbiota in Antibiotic-Treated Mice.

Antibiotics are used to control infectious diseases. However, adverse effects of antibiotics, such as devastation of the gut microbiota and enhancement of the inflammatory response, have been reported. Health benefits of fermented milk are established and can be enhanced by the addition of probiotic strains. In this study, we evaluated effects of fermented milk containing Lacticaseibacillus rhamnosus (L. rhamnosus) SNUG50430 in a mouse model with antibiotic treatment. Fermented milk containing 2 × 105 colony-forming units of L. rhamnosus SNUG50430 was administered to six week-old female BALB/c mice for 1 week. Interleukin (IL)-10 levels in colon samples were significantly increased (P < 0.05) compared to water-treated mice, whereas interferon-gamma (IFN-γ) and tumor necrosis factor alpha (TNF-α) were decreased, of mice treated with fermented milk containing L. rhamnosus SNUG50430-antibiotics-treated (FM+LR+Abx-treated) mice. Phylum Firmicutes composition in the gut was restored and the relative abundances of several bacteria, including the genera Coprococcus and Lactobacillus, were increased in FM+LR+Abx-treated mice compared to PBS+Abx-treated mice. Interestingly, abundances of genus Coprococcus and Lactobacillus were positively correlated with IL-5 and IL-10 levels (P < 0.05) in colon samples and negative correlated with IFN-γ and TNF-α levels in serum samples (P < 0.001). Acetate and butyrate were increased in mice with fermented milk and fecal microbiota of FM+LR+Abx-treated mice were highly enriched with butyrate metabolism pathway compared to water-treated mice (P < 0.05). Thus, fermented milk containing L. rhamnosus SNUG50430 was shown to ameliorate adverse health effects caused by antibiotics through modulating immune responses and the gut microbiota.

Lactic acid bacteria and yeast co-fermented milk alleviate cow milk allergy.

Cow milk allergy is one of the common food allergies. Our previous study showed that the allergenicity of fermented milk is lower than that of unfermented skimmed milk in vitro, and the antigenicity of ß-lactoglobulin and α-lactalbumin in fermented milk was decreased by 67.54% and 80.49%, respectively. To confirm its effects in vivo, allergic BALB/C mice model was used to further study the allergenicity of fermented milk. It was found that compared with the skim milk (SM) group, the intragastrically sensitization with fermented milk had no obvious allergic symptoms and the fingers were more stable: lower levels of IgE, IgG, and IgA in serum, lower levels of plasma histamine and mast cell protein-1, and immune balance of Th1/Th2 and Treg/Th17. At the same time, intragastrically sensitization with fermented milk increased the α diversity of intestinal microbiota and changed the microbiota abundance: the relative abundance of norank-f-Muribaculaceae and Staphylococcus significantly decreased, and the abundance of Lachnospiraceae NK4A136 group, Bacteroides, and Turicibacter increased. In addition, fermented milk can also increase the level of short-chain fatty acids in the intestines of mice. It turns out that fermented milk is much less allergenicity than SM. PRACTICAL APPLICATION: Fermentation provides a theoretical foundation for reducing the allergenicity of milk and dairy products, thereby facilitating the production of low-allergenic dairy products suitable for individuals with milk allergies.

Lactobacillus delbrueckii CIDCA 133 fermented milk modulates inflammation and gut microbiota to alleviate acute colitis.

Lactobacillus delbrueckii subsp. lactis CIDCA 133 is a health-promoting bacterium that can alleviate gut inflammation and improve the epithelial barrier in a mouse model of mucositis. Despite these beneficial effects, the protective potential of this strain in other inflammation models, such as inflammatory bowel disease, remains unexplored. Herein, we examined for the first time the efficacy of Lactobacillus delbrueckii CIDCA 133 incorporated into a fermented milk formulation in the recovery of inflammation, epithelial damage, and restoration of gut microbiota in mice with dextran sulfate sodium-induced colitis. Oral administration of Lactobacillus delbrueckii CIDCA 133 fermented milk relieved colitis by decreasing levels of inflammatory factors (myeloperoxidase, N-acetyl-ß-D-glucosaminidase, toll-like receptor 2, nuclear factor-κB, interleukins 10 and 6, and tumor necrosis factor), secretory immunoglobulin A levels, and intestinal paracellular permeability. This immunobiotic also modulated the expression of tight junction proteins (zonulin and occludin) and the activation of short-chain fatty acids-related receptors (G-protein coupled receptors 43 and 109A). Colonic protection was effectively associated with acetate production and restoration of gut microbiota composition. Treatment with Lactobacillus delbrueckii CIDCA 133 fermented milk increased the abundance of Firmicutes members (Lactobacillus genus) while decreasing the abundance of Proteobacteria (Helicobacter genus) and Bacteroidetes members (Bacteroides genus). These promising outcomes influenced the mice's mucosal healing, colon length, body weight, and disease activity index, demonstrating that this immunobiotic could be explored as an alternative approach for managing inflammatory bowel disease.

Bacterial proteome adaptation during fermentation in dairy environments.

The enzymatic repertoire of starter cultures belonging to the Lactococcus genus determines various important characteristics of fermented dairy products but might change in response to the substantial environmental changes in the manufacturing process. Assessing bacterial proteome adaptation in dairy and other food environments is challenging due to the high matrix-protein concentration and is even further complicated in particularly cheese by the high fat concentrations, the semi-solid state of that matrix, and the non-growing state of the bacteria. Here, we present bacterial harvesting and processing procedures that enable reproducible, high-resolution proteome determination in lactococcal cultures harvested from laboratory media, milk, and miniature Gouda cheese. Comparative proteome analysis of Lactococcus cremoris NCDO712 grown in laboratory medium and milk revealed proteome adaptations that predominantly reflect the differential (micro-)nutrient availability in these two environments. Additionally, the drastic environmental changes during cheese manufacturing only elicited subtle changes in the L. cremoris NCDO712 proteome, including modified expression levels of enzymes involved in flavour formation. The technical advances we describe offer novel opportunities to evaluate bacterial proteomes in relation to their performance in complex, protein- and/or fat-rich food matrices and highlight the potential of steering starter culture performance by preculture condition adjustments.

A randomized, double-blinded, placebo-controlled clinical trial on Lactobacillus-containing cultured milk drink as adjuvant therapy for depression in irritable bowel syndrome.

Irritable bowel syndrome (IBS) is frequently linked with coexisting mental illnesses. Our previous study discovered that 32.1% of IBS patients had subthreshold depression (SD), placing them at higher risk of developing major depression. Gut microbiota modulation through psychobiotics was found to influence depression via the gut-brain axis. However, the efficacy of lessening depression among IBS patients remains ambiguous. The study's aim was to investigate the roles of cultured milk drinks containing 109 cfu Lactobacillus acidophilus LA-5 and Lactobacillus paracasei L. CASEI-01 on depression and related variables among IBS participants with SD. A total of 110 IBS participants with normal mood (NM) and SD, were randomly assigned to one of four intervention groups: IBS-NM with placebo, IBS-NM with probiotic, IBS-SD with placebo, and IBS-SD with probiotic. Each participant was required to consume two bottles of cultured milk every day for a duration of 12 weeks. The following outcomes were assessed: depression risk, quality of life, the severity of IBS, and hormonal changes. The depression scores were significantly reduced in IBS-SD with probiotic and placebo from baseline (p < 0.001). Only IBS-SD with probiotic showed a significant rise in serotonin serum levels (p < 0.05). A significantly higher life quality measures were seen in IBS-SD with probiotic, IBS-SD with placebo, and IBS-NM with placebo (p < 0.05). All groups, both placebo and probiotic, reported significant improvement in IBS severity post-intervention with a higher prevalence of remission and mild IBS (p < 0.05). Dual strains lactobacillus-containing cultured milk drink via its regulation of relevant biomarkers, is a potential anti-depressive prophylactic agent for IBS patients at risk.

Role of fermented dairy products in the health benefits of a mediterranean diet.

Mediterranean diet includes fermented dairy products like yogurt and cheese. These foods provide calcium, phosphorus, fat, carbohydrates and protein, all nutrients influencing various systems including bone, cardiovascular system, intermediary metabolism, cancer, central nervous system, and inflammation. In addition, they contain prebiotics and provide probiotics which are capable of modifiying microbiota composition and metabolism, potentially acting also indirectly on the various systems. A large body of evidence indicates that fermented dairy products consumption significantly contributes to the beneficial effects of a Mediterranean diet on various systems' health.

Microflora structure and functional capacity in Tibetan kefir grains and selenium-enriched Tibetan kefir grains: A metagenomic analysis.

Tibetan kefir grains (TKGs) are a complex protein-lipid-polysaccharide matrix composed of various microorganisms. Microorganisms have the benefit of being effective, secure, and controllable when used for selenium enrichment. In this study, selenium-enriched Tibetan kefir grains (Se-TKGs) were made, and the microbiology composition was analyzed through a metagenomic analysis, to explore the influence of selenium enrichment. The microbial composition of TKGs and Se-TKGs, as well as the probiotic species, quorum sensing system (QS) and functional genes were compared and evaluated. Lactobacillus kefiranofaciens was the most abundant microbial species in both communities. Compared with TKGs, Se-TKGs had a much higher relative abundance of acetic acid bacteria. Lactobacillus helveticus was the most common probiotic species both in TKGs and Se-TKGs. Probiotics with antibacterial and anti-inflammatory properties were more abundant in Se-TKGs. QS analysis revealed that Se-TKGs contained more QS system-associated genes than TKGs. Moreover, Kyoto Encyclopedia of Genes and Genomes analysis revealed that the pathway for human disease ko01501 had the greatest relative abundance in both TKGs and Se-TKGs. Compared with TKGs, Se-TKGs demonstrated a greater relative abundance of different drug resistance-related metabolic pathways. Additionally, linear discriminant analysis effect size was used to examine the biomarkers responsible for the difference between the two groups. In this study, we focused on the microbiological structure of TKGs and Se-TKGs, with the aim of establishing a foundation for a more thorough investigation of Se-TKGs and providing a basis for exploring potential future use.

Yeast strains isolated from fermented beverage produce extracellular vesicles with anti-inflammatory effects.

Extracellular vesicles (EVs) are lipid-bilayered particles, containing various biomolecules, including nucleic acids, lipids, and proteins, released by cells from all the domains of life and performing multiple communication functions. Evidence suggests that the interaction between host immune cells and fungal EVs induces modulation of the immune system. Most of the studies on fungal EVs have been conducted in the context of fungal infections; therefore, there is a knowledge gap in what concerns the production of EVs by yeasts in other contexts rather than infection and that may affect human health. In this work, we characterized EVs obtained by Saccharomyces cerevisiae and Pichia fermentans strains isolated from a fermented milk product with probiotic properties. The immunomodulation abilities of EVs produced by these strains have been studied in vitro through immune assays after internalization from human monocyte-derived dendritic cells. Results showed a significant reduction in antigen presentation activity of dendritic cells treated with the fermented milk EVs. The small RNA fraction of EVs contained mainly yeast mRNA sequences, with a few molecular functions enriched in strains of two different species isolated from the fermented milk. Our results suggest that one of the mechanisms behind the anti-inflammatory properties of probiotic foods could be mediated by the interactions of human immune cells with yeast EVs.

Analysis of the Influence of Lactiplantibacillus plantarum and Lacticaseibacillus rhamnosus Strains on Changes in the Hexachlorobenzene Content in Fermented Mare Milk during Refrigerated Storage.

(1) Background: Hexachlorobenzene (HCB) is a persistent organic pollutant that is possibly carcinogenic to humans. It is still found in the environment, humans and animals, and in foods, including milk and dairy products; (2) Methods: The influence of the probiotic cultures Lacticaseibacillus rhamnosus LCR and Lactiplantibacillus plantarum subsp. plantarum LP on the possibility of effecting the biodegradation of HCB in dairy products fermented from mare milk was investigated, taking into account the product storage time (maximum 21 days). HCB content was determined using the GC/MS method; (3) Results: A strong negative Pearson correlation (p < 0.05) was found between HCB concentration and the refrigeration storage time of the fermented beverages. The highest HCB reduction was observed in milk fermented with both Lacticaseibacillus rhamnosus LCR and Lactiplantibacillus plantarum subsp. plantarum LP (78.77%), while the lowest was noted when only Lactiplantibacillus plantarum subsp. plantarum LP was used (73.79%); (4) Conclusions: This pilot study confirmed that probiotics commonly used to give products health-promoting properties can also contribute to reducing the content of undesirable substances, and the bacterial cultures used might provide an alternative method for reducing HCB residues in fermented drinks.

Effect of exopolysaccharides yield and addition concentration of Lactobacillus helveticus on the processing characteristics of fermented milk and its mechanism.

Exopolysaccharides (EPS) yield and added concentration of lactic acid bacteria can greatly affect the processing characteristics of fermented milk. In order to investigate the effects and mechanisms of EPS yield and added concentration on fermented milk, researchers extracted EPS from 50 strains of Lactobacillus helvedicus (L. helvedicus) and selected the two strains with the largest difference in EPS yield (L. helvedicus LH18 and L. helvetigus LH33) for subsequent experiments. The physicochemical properties of EPS-LH18 and EPS-LH33 were analyzed. The gel characteristics and protein conformation of fermented milk were studied by means of texture analyzer, rheometer, scanning electron microscopy, nuclear magnetic resonance machine, fluorescence spectrophotometer and circular dichroism. The results indicate that the monosaccharide compositions of EPS-LH18 and EPS-LH33 are the same and have good thermal stability. The texture and rheological properties of L. helveticus LH18 fermented milk are significantly superior to other fermented milk. The reason is that L. helveticus LH18 EPS has the highest yield, which leads to a denser gel structure, lower surface hydrophobicity and free sulfhydryl content of its fermented milk. According to circular dichroism analysis, ß- sheet and random coil are the internal factors leading to the difference in fermented milk gel. In addition, the fermented milk improved even more favorably as the concentration of the two EPS additions increased. As described above, L. helveticus LH18 has the potential to be an excellent yogurt starter, and both of the above EPS can be used as probiotic stabilizer alternatives for fermented dairy products.

The effect of dairy products on liver fat and metabolic risk markers in males with abdominal obesity - a four-arm randomized controlled trial.

BACKGROUND & AIMS: In recent years, epidemiological studies have reported links between the consumption of fermented dairy products, such as yogurt, and health; however, evidence from human intervention trials is scarce and inconsistent. We aimed to investigate the effect of consumption of four different types of dairy products (two fermented and two non-fermented) on liver fat (primary outcome) and metabolic risk markers in males with abdominal obesity. METHODS: In this parallel randomized controlled trial with four arms, 100 males aged 30-70 years, with body mass index 28.0-45.0 kg/m2, and waist circumference ≥102 cm underwent a 16-weeks intervention where they were instructed to consume 400 g/day of either milk, yogurt, heat-treated yogurt, or acidified milk as part of their habitual diet. Liver fat was measured by magnetic resonance imaging. RESULTS: In the complete case analyses (n = 80), no effects of the intervention or differences between groups were detected in anthropometry or body composition including liver fat. Moreover, no effects were detected in inflammatory markers. Main effects of time were detected in blood pressure (decrease; P < 0.001), insulin (decrease; P < 0.001), C-peptide (decrease; P = 0.040), homeostatic model assessment for insulin resistance (decrease; P < 0.001), total cholesterol (decrease; P = 0.016), low-density lipoprotein (decrease; P = 0.033), high-density lipoprotein (decrease; P = 0.006), and alanine transaminase (decrease; P = 0.019). Interactions between group and time failed to reach significance. CONCLUSIONS: In conclusion, findings from our study do not confirm that fermented yogurt products are superior in reducing liver fat or improving metabolic risk markers compared to non-fermented milk products. In fact, all intervention products (both fermented yogurt products and non-fermented milk products) did not affect liver fat and caused largely similar modest favorable changes in some metabolic risk markers. The study was registered at www. CLINICALTRIALS: gov (# NCT04755530).

Dairy product consumption and type 2 diabetes in an Argentinian population: is there an association?

Introduction: Introduction: dairy products have long been recommended as part of a healthy eating plan, but there is a controversial opinion about whether or not they should be included in the diet of people with type 2 diabetes (T2D). Objective: the aim of this study was to know if there is an association between the intake of total dairy and dairy subgroups and the chance of having T2D, and the status of markers of glucose metabolism. Methods: three hundred and forty-two adult subjects participated in the study. A validated food-frequency questionnaire was applied to establish the dairy intake. Clinical-pathological and anthropometric variables (height, weight, waist circumference and serum concentrations of blood glucose, glycated hemoglobin [HbA1c], high sensitive C-reactive protein [hs-CRP], tumor necrosis factor alpha [TNFα], interleukin [IL] 6 and IL-10) were measured. Consumption tertiles were calculated for each dairy subgroup. Correlation coefficients, multiple linear regression models and logistic regression models were used to assess the relation between dairy product consumption and markers of glucose metabolism. Results: a negative correlation was observed between the consumption of fermented dairy products and IL-10 (r = -0.27, p = 0.0206). Fermented dairy products were inversely associated with blood glucose, and HbA1c. Total dairy intake was positively associated with a lower chance of having diabetes in tertiles 2 and 3 of consumption, in relation to the reference tertile, adjusted for age, smoking habit, and alcohol intake, body mass index (BMI) and dietary variables. Conclusions: with this study, we broaden our understanding of the role of dairy intake in diabetes risk. However, more long-term studies are needed to confirm the associations and explore different confounding factors.

Introducción: Introducción: los lácteos se han recomendado durante mucho tiempo como parte de un plan de alimentación saludable, pero existen opiniones controvertidas sobre si deben incluirse en la dieta de las personas con diabetes tipo 2 (DT2). Objetivo: el objetivo fue conocer si existe asociación entre la ingesta de lácteos totales y subgrupos lácteos y la posibilidad de tener DT2, y el estado de los marcadores del metabolismo de la glucosa. Métodos: participaron 342 sujetos adultos. Se aplicó un cuestionario de frecuencia de consumo para establecer el consumo de lácteos. Se midieron variables clínicas-patológicas y antropométricas (talla, peso, circunferencia de cintura y concentraciones séricas de glucosa en sangre, hemoglobina glicosilada [HbA1c], proteína C reactiva ultrasensible [PCR-us], factor de necrosis tumoral alfa [TNFα], interleuquina [IL] 6 e IL-10). Se calcularon terciles de consumo para cada subgrupo de lácteos. Se utilizaron coeficientes de correlación, modelos de regresión lineal múltiple y regresión logística para evaluar la relación entre el consumo de lácteos y los marcadores del metabolismo de la glucosa. Resultados: los productos lácteos fermentados se asociaron inversamente con la glucosa en sangre y la HbA1c. La ingesta total de lácteos se asoció positivamente con una menor probabilidad de tener diabetes en los terciles 2 y 3 de consumo, en comparación con el tercil de referencia, ajustado por edad, tabaquismo, ingesta de alcohol, índice de masa corporal (IMC) y variables dietéticas. Conclusiones: con este estudio, ampliamos nuestra comprensión del papel de la ingesta de lácteos en el riesgo de diabetes. Sin embargo, se necesitan más estudios a largo plazo para confirmar las asociaciones y explorar diferentes factores de confusión.

Isolation and characterization of lactic acid bacteria producing a potent anti-listerial bacteriocin-like inhibitory substance (BLIS) from chhurpi, a fermented milk product.

Nowadays, the bacteriocin industries have seen significant growth, supplanting chemical preservatives in its ability to improve the shelf-life and safety of food. The increasing customer desire to use natural preservatives has fueled advancing bacteriocin research. The objective of this study was to identify lactic acid bacteria (LAB) that produce bacteriocin-like inhibitory substance (BLIS) and have strong anti-listerial activity. We have identified and analyzed a LAB obtained from chhurpi samples, a popular milk-derived product in the Himalayan regions of India and Nepal. The strain was studied and identified based on its morphological, biochemical, and physiological characteristics. Furthermore, the molecular 16s-rDNA analysis suggests that the strain was Lactococcus sp. RGUAM1 (98.2% similar to Lactococcus lactis subsp. hordniae NBRC 100931T). The isolated strain can produce a potent BLIS, which has shown efficacy against three gram-positive bacteria responsible for food spoilage, such as Listeria monocytogenes (MTCC 657), Staphylococcus aureus subsp. aureus (MTCC 87), Lactobacillus plantarum (MTCC 1407), Lactobacillus paraplantarum (MTCC 12904). The scanning electron microscope (SEM) image illustrates that the crude cell-free supernatant (CFS) disrupts the cell envelope, leading to the release of cellular contents and the clustering of cells. In addition, this BLIS can easily withstand a wide range of pH (2-12), temperature (up to 100 °C for 15 min), bile salt (0.3% W/V), salinity (4% W/V), and enzyme activity of 1600 AU/ml against Listeria monocytogenes. Our research offers a robust framework and valuable insights into bio-preservation and its potential applications in diverse food products.

Assessment of the in-vitro probiotic efficacy and safety of Pediococcus pentosaceus L1 and Streptococcus thermophilus L3 isolated from Laban, a popular fermented milk product.

Probiotics are beneficial microorganisms, mostly lactic acid bacteria (LAB), that offer health benefits to the host when consumed in adequate amounts. This study assessed the probiotic efficacy and safety of LAB strains isolated from Laban, a traditional fermented milk product. Seven primarily selected Gram-positive, catalase-negative, non-spore-forming isolates were examined for their antimicrobial activity against the bacterial pathogens Bacillus cereus, Salmonella typhi, Staphylococcus aureus, and Vibrio cholera, and the fungal pathogen Candida albicans. Two isolates, identified as Pediococcus pentosaceus L1 and Streptococcus thermophilus L3, which showed antimicrobial activity against all pathogens, were further evaluated for their probiotic competence. The selected isolates demonstrated strong resistance to low pH, bile salts, and phenol, indicating their potential for gastric endurance. They also exhibited high cell surface hydrophobicity to various hydrocarbons, autoaggregation, and coaggregation properties, demonstrating strong adhesion abilities. In addition, both isolates showed strong antioxidant activity and were non-hemolytic. Although the isolates had some resistance to certain antibiotics, they were generally susceptible to commonly used antibiotics. The two LAB strains also exhibited promising technological properties, such as milk coagulation and exopolysaccharide production, indicating their potential to enhance the quality of dairy products. The results suggest that the LAB strains isolated from Laban have strong potential as probiotics, and due to their food origin, they are highly likely to exhibit maximal efficacy in food and pharmaceutical products for human consumption.

Effect of lactic acid bacteria fermentation on cow milk allergenicity and antigenicity: A review.

Cow milk is a major allergenic food. The potential prevention and treatment effects of lactic acid bacteria (LAB)-fermented dairy products on allergic symptoms have garnered considerable attention. Cow milk allergy (CMA) is mainly attributed to extracellular and/or cell envelope proteolytic enzymes with hydrolysis specificity. Numerous studies have demonstrated that LAB prevents the risk of allergies by modulating the development and regulation of the host immune system. Specifically, LAB and its effectors can enhance intestinal barrier function and affect immune cells by interfering with humoral and cellular immunity. Fermentation hydrolysis of allergenic epitopes is considered the main mechanism of reducing CMA. This article reviews the linear epitopes of allergens in cow milk and the effect of LAB on these allergens and provides insight into the means of predicting allergenic epitopes by conventional laboratory analysis methods combined with molecular simulation. Although LAB can reduce CMA in several ways, the mechanism of action remains partially clarified. Therefore, this review additionally attempts to summarize the main mechanism of LAB fermentation to provide guidance for establishing an effective preventive and treatment method for CMA and serve as a reference for the screening, research, and application of LAB-based intervention.

Optimization of lactic acid bacterial starter culture to improve the quality and flavor characteristics of traditional Hurood.

Hurood is a traditional fermented milk product prepared by traditional Mongolian techniques of fermenting raw milk, partial degreasing, heating, whey drainage, emulsification of curd, and molding. Currently, Hurood available in the market is generally prepared by small-scale enterprises at home or in open air. Therefore, lack of standardization of bacterial starter culture leads to variation in the flavor and sensory properties of Hurood from batch to batch. In this study, we aimed to assess the best starter culture combination obtained from 37 lactic acid bacterial strains isolated from traditional Hurood. The solidification state and sensory quality were used as indexes for determining the fermentation efficiency of the bacterial starter culture combinations. The yield and texture characteristics were used to determine the optimal ratio of bacterial strains in a combination and the processing conditions for traditional Hurood production. The most optimal bacterial culture combination was observed to be NF 9-3:NF 10-4:CH 3-1 in 5:4:1 ratio and in 3% amount. The most optimal whey temperature and heating-stirring temperature were observed to be 55°C to 60°C and 85°C to 90°C, respectively. Hurood prepared with the optimal combination of bacterial strains exhibited significantly enhanced sensory quality, flavor, and contents of AA and fatty acids. Therefore, the use of optimal starter culture of lactic acid bacteria could produce Hurood with significantly superior sensory qualities, making the product more acceptable to consumers.

Proteomic Comparisons of Caprine Milk Whole Cream Buttermilk Whey and Cheese Whey Cream Buttermilk.

Buttermilk, a potential material used to produce milk fat globule membrane (MFGM), is obtained as a byproduct of butter making from milk whole cream and cheese whey cream. This study investigated the effects of rennet and acid coagulation on the protein profiles of buttermilk rennet-coagulated whey (BRW) and buttermilk acid-coagulated whey (BAW). They were compared to those of whey cream buttermilk (WCB). Rennet coagulation was more efficient in removing casein, while retaining more IgG and lactoferrin than acid coagulation. BRW had more MFGM than BAW. Butyrophilin, xanthine dehydrogenase, and mucin1 were significantly higher (P < 0.05) in BRW, while fatty acid-binding protein 3 was enriched in BAW. KEGG analysis showed that complement and coagulation cascades had the greatest differences, and the abundance of proteins involved in this signaling pathway in BRW and BAW was higher, suggesting their potential anticoagulant and anti-inflammatory activity. BAW had higher apolipoprotein A4 and transcobalamin 2, which are essential carriers for transporting long-chain fatty acids and vitamin B12 from the intestine to the blood. Therefore, BAW intake might improve lipids and vitamin B12 absorption. This study can help deepen the understanding of protein composition of MFGM-enriched whey and facilitate the production of MFGM proteins for infants and old-aged populations.