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.

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.

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.

Optimal combination of cow and quinoa milk for manufacturing of functional fermented milk with high levels of antioxidant, essential amino acids and probiotics.

The aim of this research was to produce Rayeb milk, a bio-fermented milk product that has important benefits for health and nutrition. The Rayeb milk was divided into five different treatments: T1 from cow milk, T2 from quinoa milk, T3 from a mixture of cow and quinoa milk (50%:50%), T4 from a mixture of cow and quinoa milk (75%:25%), and T5 from a mixture of cow and quinoa milk (25%:75%). As a starting culture, ABT-5 culture was used. The results demonstrated that blending quinoa milk with cow milk increased the total solids, fat, total protein, pH, acetaldehyde, and diacetyl values of the resulting Rayeb milk. Additionally, the total phenolic content, antioxidant activity, minerals, and amino acids-particularly important amino acids-in Rayeb milk with quinoa milk were higher. In Rayeb milk prepared from a cow and quinoa milk mixture, Lactobacillus acidophilus and Bifidobacterium bifidum were highly stimulated. All Rayeb milk samples, particularly those that contained quinoa milk, possessed more bifidobacteria than the recommended count of 106 cfu g-1 for use as a probiotic. Based on the sensory evaluation results, it is possible to manufacture a bio-Rayeb milk acceptable to the consumer and has a high nutritional and health values using a mixture of cow milk and quinoa milk (75%:25% or 50%:50%) and ABT-5 culture.

Integration of Meta-Multi-Omics Data Using Probabilistic Graphs and External Knowledge.

Multi-omics has the promise to provide a detailed molecular picture of biological systems. Although obtaining multi-omics data is relatively easy, methods that analyze such data have been lagging. In this paper, we present an algorithm that uses probabilistic graph representations and external knowledge to perform optimal structure learning and deduce a multifarious interaction network for multi-omics data from a bacterial community. Kefir grain, a microbial community that ferments milk and creates kefir, represents a self-renewing, stable, natural microbial community. Kefir has been shown to have a wide range of health benefits. We obtained a controlled bacterial community using the two most abundant and well-studied species in kefir grains: Lentilactobacillus kefiri and Lactobacillus kefiranofaciens. We applied growth temperatures of 30 °C and 37 °C and obtained transcriptomic, metabolomic, and proteomic data for the same 20 samples (10 samples per temperature). We obtained a multi-omics interaction network, which generated insights that would not have been possible with single-omics analysis. We identified interactions among transcripts, proteins, and metabolites, suggesting active toxin/antitoxin systems. We also observed multifarious interactions that involved the shikimate pathway. These observations helped explain bacterial adaptation to different stress conditions, co-aggregation, and increased activation of L. kefiranofaciens at 37 °C.

Exopolysaccharide-Producing Lacticaseibacillus rhamnosus Space Mutant Improves the Techno-Functional Characteristics of Fermented Cow and Goat Milks.

Lacticaseibacillus rhamnosus Probio-M9 (Probio-M9) is increasingly used as a co-fermentation culture in fermented milk production. Recently, a capsular polysaccharide (CPS)- and exopolysaccharide (EPS)-producing mutant of Probio-M9, HG-R7970-3, was generated by space mutagenesis. This study compared the performance of cow and goat milk fermentation between the non-CPS/-EPS-producing parental strain (Probio-M9) and the CPS/EPS producer (HG-R7970-3), and the stability of products fermented by the two bacteria. Our results showed that using HG-R7970-3 as the fermentative culture could improve the probiotic viable counts, physico-chemical, texture, and rheological properties in both cow and goat milk fermentation. Substantial differences were also observed in the metabolomics profiles between fermented cow and goat milks produced by the two bacteria. Comparing with Probio-M9-fermented cow and goat milks, those fermented by HG-R7970-3 were enriched in a number of flavor compounds and potential functional components, particularly acids, esters, peptides, and intermediate metabolites. Moreover, HG-R7970-3 could improve the post-fermentation flavor retention capacity. These new and added features are of potential to improve the techno-functional qualities of conventional fermented milks produced by Probio-M9, and these differences are likely imparted by the acquired CPS-/EPS-producing ability of the mutant. It merits further investigation into the sensory quality and in vivo function of HG-R7970-3-fermented milks.

Metagenome-assembled genomes for biomarkers of bio-functionalities in Laal dahi, an Indian ethnic fermented milk product.

Laal dahi is a sweetened and soft pudding-like fermented milk product of the Eastern regions of India, which has not been studied for its microbial community structures and health promoting functionality in terms of 'omics' approaches. We applied metagenomic and metagenomes-assembled genomes (MAGs) tools to decipher the biomarkers for genes encoding for different health promoting functionalities in laal dahi. Abundance of bacterial domains was observed with negligible presence of eukaryotes and viruses. Bacillota was the most abundant phylum with different bacterial species viz., Enterococcus italicus, Lactococcus raffinolactis, Lactobacillus helveticus, Bifidobacterium mongoliense, Hafnia alvei, Lactococcus lactis, Acetobacter okinawensis, Streptococcus thermophilus, Thermus thermophilus, Leuconostoc citreum, Leuconostoc pseudomesenteroides, Acetobacter orientalis, Lactobacillus gallinarum, Lactococcus chungangensis and Lactobacillus delbrueckii. Comparison of laal dahi microbiome with that of similar fermented milk products was also carried out after retrieving the metagenomic datasets from public databases. Significant abundance of Lb. helveticus, E. italicus, Lc. raffinolactis and Lc. lactis in laal dahi. Interestingly, Bifidobacterium mongoliense, Lb. gallinarum, Lc. chungangensis and Acetobacter okinawensis were only detected in laal dahi but Streptococcus infantarius, Lacticaseibacillus rhamnosus and Lb. johnsonii were absent. Reconstruction of putative single environment-specific genomes from metagenomes in addition to subsampling of the abundant species resulted in five high-quality MAGs identified as Lactobacillus delbrueckii, Lactobacillus helveticus, Lactococcus chungangensis, Lactococcus lactis and Streptococcus thermophilus. All MAGs showed the presence of various genes with several putative functions corresponding to different probiotic and prebiotic functions, short-chain fatty acids production, immunomodulation, antitumor genes, essential amino acid and vitamin biosynthesis. Genes for γ-Aminobutyric acid (GABA) production were only detected in MAG of Lactococcus lactis. Gene clusters for secondary metabolites (antimicrobial peptides) were detected in all MAGs except Lc. chungangensis. Additionally, detection of clustered regularly interspaced short palindromic repeats (CRISPR)-associated (Cas) elements was observed only in Lactobacillus delbrueckii and Streptococcus thermophilus. Annotation of several genes with potential health beneficial properties in all five MAGs may support the need to explore the culturability of these MAGs for future use in controlled fermentation of functional dairy products.

Metagenomic analysis and antibacterial activity of kefir microorganisms.

The microbiota composition of kefir grain and milk kefir was assessed via a metagenomic approach. Significant microorganisms were isolated and identified using molecular methods. A safety assessment was conducted based on antibiotic susceptibility and blood hemolysis. Probiotic traits such as resistance to gastric tract conditions, surface characteristics, adhesion to intestinal cells, and antibacterial activity were also assessed. Metagenomic analysis revealed that kefir grains are a more stable community with clear dominant species as compared to milk kefir. Lactobacillus kefiranofaciens BDGO-A1, Lactobacillus helveticus BDGO-AK2, and Lactobacillu kefiri strains showed tolerance to acidic pH and the presence of bile salts, adhesion capability to Caco-2 cells, in vitro antibacterial activity, and the production of antibacterial proteins. In the metagenomic analysis, contigs associated with these species showed the presence of genes involved in exporting polyketide antibiotics and bacteriocin production. To fully exploit the potential probiotic properties of these microorganisms to help human health, further investigation is necessary to elucidate the mechanisms behind the biological activity and the genotypic characteristics of the isolated strains.

Development of innovative fermented products by exploiting the diversity of immunomodulatory properties and fermentative activity of lactic and propionic acid bacteria.

Many consumers nowadays demand plant-based milk analogs for reasons related to lifestyle, health, diet and sustainability. This has led to the increasing development of new products, fermented or not. The objective of the present study was to develop a plant-based fermented product (based on soy milk analog or on hemp milk analog), as well as mixes, using lactic acid bacteria (LAB) and propionic acid bacteria (PAB) strains, as well as consortia thereof. We screened a collection of 104 strains, from nine LAB species and two PAB species, based on their ability to ferment plant or milk carbohydrates, to acidify goat milk, soy milk analog and hemp milk analog, as well as to hydrolyze proteins isolated from these three products. Strains were also screened for their immunomodulatory ability to induce secretion of two interleukins, i.e., IL-10 and IL-12, in human Peripheral Blood Mononuclear Cells. We selected five strains: Lactobacillus delbrueckii subsp. lactis Bioprox1585, Lactobacillus acidophilus Bioprox6307, Lactococcus lactis Bioprox7116, Streptococcus thermophilus CIRM-BIA251, and Acidipropionibacterium acidipropionici CIRM-BIA2003. We then assembled them in 26 different bacterial consortia. Goat milk and soy milk analog fermented by each of the five strains or by the 26 consortia were tested in vitro, for their ability to modulate inflammation in cultured Human Epithelial Intestinal Cells (HEIC) stimulated by pro-inflammatory Lipopolysaccharides (LPS) from Escherichia coli. Plant-based milk analogs, fermented by one consortium composed of L.delbrueckii subsp. lactis Bioprox1585, Lc.lactis Bioprox7116, and A.acidipropionici CIRM-BIA2003, reduced the secretion of the proinflammatory cytokine IL-8 in HIECs. Such innovative fermented vegetable products thus open perspectives as functional foods targeting gut inflammation.

Metagenomic insights into bacterial communities and functional genes associated with texture characteristics of Kazakh artisanal fermented milk Ayran in Xinjiang, China.

The complex microflora of traditional fermented milk is crucial to milk coagulation mainly through acid and protease production; however, it is still unclear which microbes and proteases significantly influence the texture of Ayran, a Kazakh artisanal fermented milk in Xinjiang, China. In this study, fifty-nine samples of Ayran were collected and investigated on texture properties. Finally, six Ayran samples with different texture features were screened out, and the taxonomic and functional attributes of their microbiota were characterized by metagenomics. The results showed that the hardness of the fermented milk in Yili Kazakh Autonomous Prefecture was significantly higher than that in other pasture areas. Lactobacillus and Lactococcus were the core genera that affected the coagulation quality of milk. Furthermore, we found that the proline iminopeptidase pip (EC 3.4.11.5) gene of Lactobacillus helveticus and Limosilactobacillus fermentum and the dipeptidase E pepE (EC 3.4.13.21) gene of Lactococcus lactis were most associated with the coagulation quality of fermented milk. Furthermore, positive correlations were observed among the hardness of fermented milk, the activity of the proteases, and the corresponding functional gene expressions.

Effect of Storage Time and Bacterial Strain on the Quality of Probiotic Goat's Milk Using Different Types and Doses of Collagens.

Recently, increasing attention has been focused on developing new products based on goat's milk. Consumers positively perceive fermented goat's milk products as health-promoting due to their nutritional value, digestibility, and potential source of probiotics. This study aimed to evaluate the possibility of using different doses of collagen and collagen hydrolysate in the production of probiotic goat's milk fermented by four monocultures: Lacticaseibacillus casei 431® Lactobacillus acidophilus LA- 5®, Lacticaseibacillus paracasei LP26, and Lacticaseibicillus rhamnosus Lr- 32®. A total of 20 experimental groups were prepared, including control groups (without additives), and due to the added probiotic (Lacticaseibacillus casei, Lactobacillus acidophilus, Lacticaseibacillus paracasei, and Lacticaseibacillus rhamnosus), various collagen doses (1.5% and 3.0%) and collagen types (hydrolysate and bovine collagen). Physicochemical, organoleptic, and microbiological characteristics were evaluated after 1 and 21 days of cold storage. The applied additives increased the acidity of the milk even before fermentation. However, milk with bovine collagen and hydrolysate had a higher pH value after fermentation than control milk. The study showed higher than 8 log cfu g−1 viability of probiotic bacteria in goat's milk products during storage due to the proper pH, high buffering capacity, and rich nutrient content of goat's milk. The best survival rate was shown for the L. casei strain after 21 days in milk with collagen protein hydrolysate. Moreover, collagen in milk fermented by L. rhamnosus decreased syneresis compared to its control counterpart. The addition of collagen, especially the hydrolysate, increased the gel hardness of the fermented milk. The collagen additives used in the milk, both in the form of hydrolysate and bovine collagen, caused a darkening of the color of the milk and increased the intensity of the milky-creamy and sweet taste.

Safety Evaluation of Goat Milk Added with the Prebiotic Inulin Fermented with the Potentially Probiotic Native Culture Limosilactobacillus mucosae CNPC007 in Co-culture with Streptococcus thermophilus QGE: Analysis of Acute and Repeated Dose Oral Toxicity.

Despite functional goat milk products having emerged due to their importance for human nutrition and health, few studies have assessed the safety of consumption of goat dairy products containing potentially probiotic autochthonous lactic acid bacteria supplemented with prebiotic carbohydrates. Aiming this field, this study evaluated the safety of goat's milk fermented with Streptococcus thermophilus QGE, the autochthonous Limosilactobacillus mucosae CNPC007 culture, and the prebiotic inulin, through single- and repeated-dose oral toxicity tests (SDT and RDT, respectively) in animals. Ten female Swiss Webster mice were used for SDT evaluation - 2 groups, SDTc (20 mL/kg of filtered water) and SDTt (20 mL/kg of fermented milk) - and 40 Wistar rats for RDT - RDT3, RDT6, and RDT12 (treated with fermented milk at doses of 3 mL/kg, 6 mL/kg, and 12 mL/kg, respectively) and also RDTc (12 mL/kg of filtered water). For SDT, no signs of mortality or toxicity were observed, and the animals maintained the expected weight gain and feed intake. The RDT trials did not show mortality or signs of toxicity, as well as no change in body weight and organs, in the hematological and biochemical parameters, and also in relation to morphology and histology. Since the fermented milk did not cause any toxic effect in the conditions evaluated, it can be said that its no-adverse effect level (NOAEL) was considered to be higher than 20 mL/kg/day. Thus, the fermented milk with L. mucosae CNPC007 and inulin was considered to be of low toxicity, safe for use in rodents, and allowed for use in further studies.

Impact of lactic acid bacteria and their metabolites on the techno-functional properties and health benefits of fermented dairy products.

After conversion of lactose to lactic acid, several biochemical changes occur such as enhanced protein digestibility, fatty acids release, and production of bioactive compounds etc. during the fermentation process that brings nutritional and quality improvement in the fermented dairy products (FDP). A diverse range of lactic acid bacteria (LAB) is being utilized for the development of FDP with specific desirable techno-functional attributes. This review contributes to the knowledge of basic pathways and changes during fermentation process and the current research on techniques used for identification and quantification of metabolites. The focus of this article is mainly on the metabolites responsible for maintaining the desired attributes and health benefits of FDP as well as their characterization from raw milk. LAB genera including Lactobacillus, Streptococcus, Leuconostoc, Pediococcus and Lactococcus are involved in the fermentation of milk and milk products. LAB species accrue these benefits and desirable properties of FDP producing the bioactive compounds and metabolites using homo-fermentative and heterofermentative pathways. Generation of metabolites vary with incubation and other processing conditions and are analyzed and quantified using highly advanced and sophisticated instrumentation including nuclear magnetic resonance, mass-spectrometry based techniques. Health benefits of FDP are mainly possible due to the biological roles of such metabolites that also cause technological improvements desired by dairy manufacturers and consumers.

Molecular characterization of five novel plasmids from Enterococcus italicus SD1 isolated from fermented milk: An insight into understanding plasmid incompatibility.

Enterococcal plasmids have attracted considerable interest because of their indispensable role in the pathogenesis and dissemination of multidrug-resistance. In this work, five novel plasmids pSRB2, pSRB3, pSRB4, pSRB5 and pSRB7 have been identified and characterised, coexisting in Eneterococcus italicus SD1 from fermented milk. The plasmids pSRB2, pSRB3 and pSRB5 were found to replicate via theta mode of replication while pSRB4 and pSRB7 were rolling-circle plasmids. Comparative analysis of SD1-plasmids dictated that the plasmids are mosaic with novel architecture. Plasmids pSRB2 and pSRB5 are comprised of a typical iteron-based class-A theta type origin of replication, whereas pSRB3 has a Class-D theta type replication origin like pAMß1. The plasmids pSRB4 and pSRB7 shared similar ori as in pWV01. The SD1 class-A theta type plasmids shared significant homology between their replication proteins with differences in their DNA-binding domain and comprises of distinct iterons. The differences in their iterons and replication proteins restricts the "handcuff" formation for inhibition of plasmid replication, rendering to their compatibility to coexist. Similarly, for SD1 rolling circle plasmids the differences in the replication protein binding site in the origin and the replication protein supports their coexistence by inhibiting the crosstalk between the origins and replication proteins. The phylogenetic tree of their replication proteins revealed their distant kinship. The results indicate that the identified plasmids are unique to E. italicus SD1, providing further opportunities to study their utility in designing multiple gene expression systems for the simultaneous production of proteins in enterococci with the renewed concept of plasmid incompatibility.

Composition and factors influencing community structure of lactic acid bacterial in dairy products from Nyingchi Prefecture of Tibet.

This study investigated the community composition of lactic acid bacteria (LAB) from yaks' milk (YM) Tibetan yellow cattle milk (TM) and their fermented products from different counties in the Nyingchi Prefecture, Tibet using Pacific Biosciences (PacBio) single-molecule real-time (SMRT) sequencing. Sequencing revealed 26 genera and 94 species from 71 dairy samples; amongst these Lactobacillus delbrueckii (36.17%), Streptococcus thermophilus (19.46%) and Lactococcus lactis (18.33%) were the predominant species. This study also identified the main factors influencing LAB community composition by comparing amongst samples from different locations, from different milk types, and from different altitudes. The LAB communities in YM and TM were more diverse than in fermented yaks' milk (FYM) and fermented Tibetan yellow cattle milk (FTM) samples. Similarly, whether milk was fermented or not accounted for differences in LAB species composition while altitude of the dairy products had very little effect. Milk source and production process were the most likely causes of drastic shifts in microbial community composition. In addition, fermented dairy products were enriched in genes responsible for secondary metabolic pathways that were potentially beneficial for health. Comprehensive descriptions of the microbiota in different dairy products from the Nyingchi Prefecture, Tibet might help elucidate evolutionary and functional relationships amongst bacterial communities in these products.

FDF-DB: A Database of Traditional Fermented Dairy Foods and Their Associated Microbiota.

BACKGROUND: Fermented foods are attracting increasing interest due to their nutritional and health benefits, including a positive impact on gut microbiota exerted by their associated microbes. However, information relative to traditional fermented dairy products, along with their autochthonous microbiota, is still fragmented and poorly standardized. Therefore, our aim was to collect and aggregate data useful for obtaining a comprehensive overview translated in a classical database interface that can be easily handled by users. METHODS: a preliminary inventory was built up by systematically collecting data from publicly available resources for the creation of a list of traditional dairy foods produced worldwide, including additional metadata useful for stratifying, and collapsing subgroups. RESULTS: we developed the Fermented Dairy Food Database (FDF-DB), a feasible resource comprising 1852 traditional dairy foods (cheeses, fermented milks, and yogurt) for which microbial content and other associated metadata such as geographical indication label, country/region of origin, technological aspects were gathered. CONCLUSIONS: FDF-DB is a useful and user-friendly resource where taxonomic information and processing production details converge. This resource will be of great aid for researchers, food industries, stakeholders and any user interested in the identification of technological and microbiological features characterizing traditional fermented dairy products.

Dairy starters and fermented dairy products modulate gut mucosal immunity.

The gut microbiota plays a crucial role in the regulation of mucosal immunity and of the function of the intestinal barrier. Dysbiosis is accordingly associated with rupture of mucosal immune homeostasis, leading to inflammatory intestinal diseases. In this context, probiotic bacteria, including a new generation of intestinal probiotics, can maintain intestinal homeostasis and promote health. Surprisingly, little is known about the impact of fermented dairy products in this context, while they represent our main source of live and active bacteria. Indeed, they provide, through our daily diet, a high number of bacteria whose effect on mucosal immunity deserves attention. Among bacteria ingested in fermented dairy products, Streptococcus thermophilus, Lactobacillus delbrueckii, Lactobacillus helveticus, Lactococcus lactis and Propionibacterium freudenreichii are on top, as they are ingested in high concentrations (close to 109 per gram of product) in fermented milks or cheeses. This review gives an overview of the potential immunomodulatory effects of these main dairy starters. It further explores studies dealing with fermented dairy products containing theses starters, in a context of inflammation.

Antibacterial Property and Metagenomic Analysis of Milk Kefir.

Milk kefir fermentation has been used in households for generations. Consumption of milk kefir has been associated with various health benefits, presumably from the probiotics of yeast and bacteria that make up the kefir grains. In addition, many of the microbes are known to produce novel antimicrobial compounds that can be used for other applications. The microbes living inside kefir grains differ significantly depending on geographical location and production methods. In this study, we aimed to use metagenomic analysis of fermented milk by using three different kefir grains (kefir 1, kefir 2, and kefir 3) from different US sources. We analyzed the microbial compositions of the three milk fermentation samples. This study revealed that each sample contains unique and distinct groups of microbes, kefir 1 showed the least diversity, and kefir 3 showed the highest diversity. Kefir 3 is rich in Proteobacteria while kefir 2 is dominated by the Firmicutes. Using bacterial indicator growth analyses carried out by continuous readings from microplate-based bioreactor assays suggested that kefir 2 fermentation filtrate has higher antibacterial property. We have screened 30 purified cultures of kefir 2 sample and isolated two lactic acid bacteria strains with higher antibacterial activities; the two strains were identified as Leuconostoc mesenteroides 28-1 and Lentilactobacillus kefiri 25-2 by 16S genomic PCR with confirmed antibacterial activities of fermentation filtrate after growing under both aerobic and anaerobic conditions.

[The role of ferments in food sustainability]. / El rol de los fermentos en la sostenibilidad alimentaria.

Introduction: Food fermentation is one of the oldest conservation techniques and has evolved over the centuries. This study contributes to the understanding of the impact of fermentation and consequently of fermented products in the evolution of humanity and its influence on sustainability and food use. The production of fermented dairy products is the second industry after alcoholic beverages; thus, yogurt is one of the main fermented products consumed worldwide. Considering fermentation as a technology, this brings us different benefits such as sustainability, since in Spain each person wastes 77 kilos of food per year in their homes and we know that 9% of food waste in our country corresponds to dairy products. For this reason, we have worked with different ferments to select those that allow us to extend the useful life of the product, making it more flexible in its distribution and conservation. Also considering food safety due to the change in pH and the production of certain substances that will protect against pathogens and undesirable bacteria, guaranteeing the highest quality standards.

Introducción: La fermentación de los alimentos constituye una de las técnicas de conservación más antiguas, que ha ido evolucionando a lo largo de los siglos. Este estudio contribuye a la comprensión del impacto de la fermentación y, en consecuencia, de los productos fermentados en la evolución de la humanidad y su influencia en la sostenibilidad y en el aprovechamiento alimentario. La elaboración de productos lácteos fermentados es la segunda industria después de la de bebidas alcohólicas, así pues, el yogur es uno de los principales productos fermentados consumidos en todo el mundo. Considerando la fermentación como una tecnología, esta nos aporta distintos beneficios como la sostenibilidad, ya que en España cada persona desperdicia 77 kilos de alimentos al año en sus hogares y sabemos que el 9 % del desperdicio alimentario en nuestro país corresponde a los lácteos. Por esta razón, se ha trabajado con diferentes fermentos para seleccionar aquellos que permitan alargar la vida útil del producto y hacerlo más flexible en su distribución y conservación, teniendo en cuenta también la seguridad alimentaria debido al cambio de pH y a la producción de determinadas sustancias que protegen frente a patógenos y bacterias indeseables, garantizando los máximos estándares de calidad.

Exopolysaccharides of Lactic Acid Bacteria: Production, Purification and Health Benefits towards Functional Food.

Lactic acid bacteria (LAB) are capable of synthesising metabolites known as exopolysaccharides (EPS) during fermentation. Traditionally, EPS plays an important role in fermented dairy products through their gelling and thickening properties, but they can also be beneficial to human health. This bioactivity has gained attention in applications for functional foods, which leads them to have prebiotic, immunomodulatory, antioxidant, anti-tumour, cholesterol-lowering and anti-obesity activity. Understanding the parameters and conditions is crucial to optimising the EPS yields from LAB for applications in the food industry. This review provides an overview of the functional food market together with the biosynthesis of EPS. Factors influencing the production of EPS as well as methods for isolation, characterisation and quantification are reviewed. Finally, the health benefits associated with EPS are discussed.