Search Results (15)

Foodborne diseases represent a major public health concern, particularly those associated with dairy products contaminated with Staphylococcus aureus, a pathogen capable of producing heat-stable enterotoxins. This study evaluated the potential of native lactic acid bacteria (LAB) isolated from artisanal kefir grains as natural biocontrol agents in fermented dairy foods. Kefir grains obtained from three artisanal producers were microbiologically characterized, revealing LAB as the dominant group and the absence of Enterobacteriaceae. Strains belonging mainly to the genera Lactobacillus sensu lato, Leuconostoc, and Pediococcus were isolated and exhibited differentiated metabolic profiles. Safety assessment showed no hemolytic activity and an overall susceptibility to clinically relevant antibiotics, although genus-dependent intrinsic resistance patterns were observed. Several strains displayed enzymatic activities related to carbohydrate digestion and high tolerance to simulated gastrointestinal conditions, with survival rates exceeding 90% during both gastric and intestinal phases. Neutralized cell-free supernatant (CFS) demonstrated differential inhibitory activity, with significant antagonism of S. aureus and E. coli, comparable to those of commercial reference strains. In a yogurt model system stored at 4 °C, selected Lactobacillus and Pediococcus strains induced a progressive and significant reduction in S. aureus populations, achieving complete elimination to undetectable levels in shorter times than commercial probiotic strains. Overall, these results demonstrate that native LAB from artisanal kefir grains exhibit an adequate safety and functional profile, together with strong antagonistic activity, supporting their potential application as natural protective cultures to improve the food hygiene of fermented dairy products. Full article

Background: Fermentation is among the oldest and most versatile food processing techniques, enhancing not only shelf life but also nutritional and functional value. While Asian and Western fermented foods are extensively studied, traditional Eastern European fermentations—such as sauerkraut, kefir, bryndza, kvass, and sourdough—remain largely unexplored despite their enduring cultural and dietary importance. These foods combine spontaneous or mixed-culture fermentations, diverse substrates, and unique microbial consortia that may yield distinct bioactive profiles with potential health benefits. Methods: This narrative review synthesizes data from scientific articles, regional reports, and ethnographic sources retrieved from PubMed, Scopus, and Google Scholar up to 2025. Studies were selected for relevance to composition, microbiology, bioactive compounds, and human or experimental health outcomes related to Eastern European fermented foods. Results: Available evidence indicates that traditional fermented dairy, cereal, and vegetable products from Eastern Europe contain fermentation-derived bioactive compounds, including specific bioactive peptides, transformed polyphenols, microbial-synthesized vitamins, organic acids, and live or non-viable microorganisms. Experimental studies describe the generation of ACE-inhibitory peptides, polyphenol biotransformation, and prebiotic or postbiotic metabolites with reported antioxidant, antihypertensive, immunomodulatory, and metabolic effects. However, substantial variability in artisanal production practices and the limited number of standardized human studies currently constrain definitive conclusions. Conclusions: Eastern European fermented foods represent a culturally unique yet scientifically undercharacterized component of functional nutrition. Their complex microbial ecosystems and diverse substrates offer valuable models for studying diet–microbe interactions. Further omics-based and clinical research is warranted to clarify bioavailability, mechanisms of action, and their potential integration into evidence-based dietary strategies. Full article

Dairy products harbor complex and dynamic microbial communities that contribute to their sensory properties, safety, and cultural distinctiveness. Raw milk contains a diverse microbiota shaped by seasonality, storage conditions, lactation stage, animal health, farm management, and genetics, serving as a variable starting point for further processing. Fermentation, whether spontaneous or starter driven, selects for subsets of lactic acid bacteria (LAB), yeasts, and molds, resulting in microbial succession that underpins both artisanal and industrial products such as kefir and cheese. Kefir represents a balanced LAB–yeast symbiosis, with species composition influenced by grain origin, milk type, and processing parameters, whereas the cheese microbiota reflects the interplay of starter and non-starter LAB, coagulants, ripening conditions, and “house microbiota”. Methodological factors—including DNA extraction, sequencing platform, and bioinformatic pipelines—further impact the reported microbial profiles, highlighting the need for standardization across studies. This review synthesizes current knowledge on raw milk, kefir, and cheese microbiomes, emphasizing the biological, technological, environmental, and methodological factors shaping microbial diversity. A holistic understanding of these drivers is essential to preserve product authenticity, ensure safety, and harness microbial resources for innovation in dairy biotechnology. Full article

Buffalo milk is a rich source of precursor fatty acids for bioactive compounds and provides an optimal environment for bacterial growth. This study aimed to isolate and select lactic acid bacteria strains with potential to conjugated linoleic acid (CLA) production for technological application in fermented buffalo milk. Fifty-eight strains were isolated from raw milk, kefir, artisanal cheese, kombucha, and jaboticaba juice and tested for CLA biosynthesis. In milk fermentation, selected strains with linoleic acid (LA) conversion rates ranging from 65.66% to 21.86% were L. paraplantarum, L. plantarum, P. pentosaceus, and L. fermentum. The highest viability average values between 11.85 and 11.15 Log CFU/mL were observed after 8 h of fermentation for the L. plantarum, control L. plantarum, and L. fermentum treatments, while it took 10 h of fermentation for L. paraplantarum and P. pentosaceus to reach a stationary phase, with pH stabilizing at 4.60 ± 0.1 after 30 h. Despite L. paraplantarum showing the highest in vitro CLA production (0.99 mg/mL), in buffalo milk, all strains similarly produced c9t11 CLA, with no detectable t11c12 CLA. P. pentosaceus and L. fermentum showed a fatty acid profile with higher PUFA content, especially in CLA and MUFA, related to a lower degree of atherogenicity (IA) and thrombogenicity index (ThI). These findings boost understanding of dairy (raw milk, artisanal cheese, and milk kefir) and non-dairy substrates (kombucha and jaboticaba juice) as reservoirs for functional bacteria and highlight buffalo milk as a matrix for diversification of naturally enriched fermented dairy products. Full article

Kefir, a traditional probiotic beverage with significant cultural, social, and health relevance, has garnered increasing scientific interest for its functional properties. Here, we synthesized findings from 14 studies investigating the bacterial and fungal diversity in artisanal cow’s milk kefir through metagenomic analysis. Following the PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses), a comprehensive search was conducted in databases including Portal BVS, Scopus, Scielo, and Web of Science. From an initial pool of 522 articles, 14 were selected based on stringent inclusion and exclusion criteria, focusing on English-written studies. Key terms such as “kefir milk”, “artisanal kefir”, “milk”, “metagenomics”, and “cow” were identified through Boolean searches over the last five years. This review addresses the growing need for research on the microbial diversity of artisanal cow’s milk kefir from various global regions. The results indicate a remarkable diversity in microbial communities, primarily dominated by bacteria from the phylum Firmicutes (notably Lactobacillus) and yeasts from the genera Saccharomyces and Kluyveromyces. These microbial compositions are shaped by factors such as milk type, production methods, and grain handling practices, reflecting regional adaptations and influencing kefir’s sensory, probiotic, and functional properties. We argue that a full understanding of these microbial dynamics is critical for standardizing production processes and enhancing quality control measures, ultimately ensuring artisanal kefir’s consistency and health benefits. Full article

Artisanal kefir is produced by fermenting milk with kefir grains, resulting in a lightly carbonated drink with health-promoting bioactive compounds. However, sensory variability and fermentation conditions challenge its standardization, limiting commercialization in Brazil due to regulatory requirements. This study evaluated the physicochemical properties, volatile compounds, and microbiological stability of artisanal kefir produced in southern Brazil during 30 days of storage. Metabarcoding analysis, carried out by sequencing the V3/V4 regions of the 16S rRNA gene (bacteria) and the ITS region (fungi), revealed an increase in bacterial diversity, with a predominance of Enterococcus and Acetobacter, while fungal diversity decreased, with a predominance of Kazachstania. The physicochemical parameters remained stable. The concentration of volatile compounds, analyzed using a gas chromatograph coupled to a mass spectrometer, decreased, except for an increase in 2-heptanol. The aromatic profile was enriched with alcohols and ketones, possibly influenced by Enterococcus and Acetobacter. These findings show that kefir maintained microbiological stability and adequate sensory characteristics throughout the period analyzed. The study provides subsidies for the standardization of artisanal kefir and compliance with Brazilian quality standards, as well as guiding future research into durability, quality, and consumer perception. Full article

This is the first study that investigates the effect of kefir with an emphasis on the production of short-chain fatty acids (SCFAs) during the fermentation process in food products. The products developed and characterized were an artisanal cream cheese without cream and one with added cream, and for the analysis of the fatty acid profile, both cream cheeses were compared with commercial cream cheese. The artisanal cream cheese had a high amount of lactic acid bacteria characterizing the product formed by Lactobacilli and a low concentration of lactose due to the fermentation process. Compared to commercial cream cheese, our products without and with added cream had a higher concentration of short-chain fatty acids (SCFAs), especially butyric acid, which is important for the health of the gastrointestinal tract, omega 3, and oleic fatty acid, which has been associated with the prevention and control of some diseases. Overall, the artisanal cream cheese cream with fermented cream with kefir grains is a functional product with an innovative character compared to current products on the market and was well accepted by the younger public. This new product comes as an option for those who need to change their eating habits and maintain a healthy lifestyle. Full article

Fermented milk products (FMPs) contain probiotics that are live bacteria considered to be beneficial to human health due to the production of various bioactive molecules. In this study, nine artisanal FMPs (kefir, ayran, khurunga, shubat, two cottage cheeses, bryndza, khuruud and suluguni-like cheese) from different regions of Russia were characterized using metagenomics. A metagenomic sequencing of ayran, khurunga, shubat, khuruud and suluguni-like cheese was performed for the first time. The taxonomic profiling of metagenomic reads revealed that Lactococcus species, such as Lc. lactis and Lc. cremoris prevailed in khuruud, bryndza, one sample of cottage cheese and khurunga. The latter one together with suluguni-like cheese microbiome was dominated by bacteria, affiliated to Lactobacillus helveticus (32–35%). In addition, a high proportion of sequences belonging to the genera Lactobacillus, Lactococcus and Streptococcus but not classified at the species level were found in the suluguni-like cheese. Lactobacillus delbrueckii, as well as Streptococcus thermophilus constituted the majority in another cottage cheese, kefir and ayran metagenomes. The microbiome of shubat, produced from camel’s milk, was significantly distinctive, and Lentilactobacillus kefiri, Lactobacillus kefiranofaciens and Bifidobacterium mongoliense represented the dominant components (42, 7.4 and 5.6%, respectively). In total, 78 metagenome-assembled genomes with a completeness ≥ 50.2% and a contamination ≤ 8.5% were recovered: 61 genomes were assigned to the Enterococcaceae, Lactobacillaceae and Streptococcaceae families (the Lactobacillales order within Firmicutes), 4 to Bifidobacteriaceae (the Actinobacteriota phylum) and 2 to Acetobacteraceae (the Proteobacteria phylum). A metagenomic analysis revealed numerous genes, from 161 to 1301 in different products, encoding glycoside hydrolases and glycosyltransferases predicted to participate in lactose, alpha-glucans and peptidoglycan hydrolysis as well as exopolysaccharides synthesis. A large number of secondary metabolite biosynthetic gene clusters, such as lanthipeptides, unclassified bacteriocins, nonribosomal peptides and polyketide synthases were also detected. Finally, the genes involved in the synthesis of bioactive compounds like β-lactones, terpenes and furans, nontypical for fermented milk products, were also found. The metagenomes of kefir, ayran and shubat was shown to contain either no or a very low count of antibiotic resistance genes. Altogether, our results show that traditional indigenous fermented products are a promising source of novel probiotic bacteria with beneficial properties for medical and food industries. Full article

Wild artisanal cultures, such as a symbiotic culture of bacteria and yeasts (SCOBY) and water kefir grains (WKG), represent a complex microorganism consortia that is composed of yeasts and lactic and acetic acid bacteria, with large strains of diversity and abundance. The fermented products (FPs) obtained by the microbiome’s contribution can be included in functional products due to their meta-biotics (pre-, pro-, post-, and paraprobiotics) as a result of complex and synergistic associations as well as due to the metabolic functionality. In this study, consortia of both SCOBY and WKG were involved in the co-fermentation of a newly formulated substrate that was further analysed, aiming at increasing the postbiotic composition of the FPs. Plackett–Burman (PBD) and Response Surface Methodology (RSM) techniques were employed for the experimental designs to select and optimise several parameters that have an influence on the lyophilised starter cultures of SCOBY and WKG activity as a multiple inoculum. Tea concentration (1–3%), sugar concentration (5–10%), raisins concentration (3–6%), SCOBY lyophilised culture concentration (0.2–0.5%), WKG lyophilised culture concentration (0.2–0.5%), and fermentation time (5–7 days) were considered the independent variables for mathematical analysis and fermentation conditions’ optimisation. Antimicrobial activity against Bacillus subtilis MIUG B1, Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, and Aspergillus niger MIUG M5, antioxidant capacity (DPPH), pH and the total acidity (TA) were evaluated as responses. The rich postbiotic bioactive composition of the FP obtained in optimised biotechnological conditions highlighted the usefulness of the artisanal co-cultures, through their symbiotic metabolic interactions for the improvement of bioactive potential. Full article

Wild probiotic consortia of microorganisms (bacteria and yeasts) associated in the artisanal cultures’ microbiota (milk kefir grains, water kefir grains and kombucha) are considered valuable promoters for metabiotics (prebiotics, probiotics, postbiotics and paraprobiotics) production. The beneficial effects of the fermented products obtained with the artisanal cultures on human well-being are described by centuries and the interest for them is continuously increasing. The wild origin and microbial diversity of these above-mentioned consortia give them extraordinary protection capacity against microbiological contaminants in unusual physico-chemical conditions and unique fermentative behaviour. This review summarizes the state of the art for the wild artisanal cultures (milk and water kefir grains, respectively, kombucha—SCOBY), their symbiotic functionality, and the ability to ferment unconventional substrates in order to obtain valuable bioactive compounds with in vitro and in vivo beneficial functional properties. Due to the necessity of the bioactives production and their use as metabiotics in the modern consumer’s life, artisanal cultures are the perfect sources able to biosynthesize complex functional metabolites (bioactive peptides, antimicrobials, polysaccharides, enzymes, vitamins, cell wall components). Depending on the purposes of the biotechnological fermentation processes, artisanal cultures can be used as starters on different substrates. Current studies show that the microbial synergy between bacteria—yeast and/or bacteria—offers new perspectives to develop functional products (food, feeds, and ingredients) with a great impact on life quality. Full article

Isolation and functional characterization of microorganisms are relevant steps for generating starter cultures with functional properties, and more recently, those related to improving mental health. Milk kefir grains have been recently investigated as a source of health-related strains. This study focused on the evaluation of microorganisms from artisanal Mexican milk kefir grains regarding probiotic properties, in vitro fermentability with commercial prebiotics (lactulose, inulin, and citrus pectin), and γ-aminobutyric acid (GABA)-producing capacity. Microorganisms were identified belonging to genera Lactococcus, Lactobacillus, Leuconostoc, and Kluyveromyces. The probiotic properties were assessed by aggregation abilities, antimicrobial activity, antibiotic susceptibility, and resistance to in vitro gastrointestinal digestion, showing a good performance compared with commercial probiotics. Most of isolates maintained a concentration above 6 log colony forming units/mL after the intestinal phase. Specific isolates of Kluyveromyces (BIOTEC009 and BIOTEC010), Leuconostoc (BIOTEC011 and BIOTEC012), and Lactobacillus (BIOTEC014 and BIOTEC15) showed a high fermentability in media supplemented with commercial prebiotics. The capacity to produce GABA was classified as medium for L. lactis BIOTEC006, BIOTEC007, and BIOTEC008; K. lactis BIOTEC009; L. pseudomesenteroides BIOTEC012; and L. kefiri BIOTEC014, and comparable to that obtained for commercial probiotics. Finally, a multivariate approach was performed, allowing the grouping of 2–5 clusters of microorganisms that could be further considered new promising cultures for functional dairy food applications. Full article

Among artisanal fermented beverages, kefir (fermented milk drink) and water kefir (fermented nondairy beverage) are of special interest because their grains can be considered natural reservoirs of safe and potentially probiotic strains. In the last years, several reports on Lacticaseibacillus paracasei (formerly Lactobacillus paracasei) isolated from both artisanal fermented beverages were published focusing on their health-promoting properties. Although this is not the predominant species in kefir or water kefir, it may contribute to the health benefits associated to the consumption of the fermented beverage. Since the classification of L. paracasei has been a difficult task, the selection of an adequate method for identification, which is essential to avoid mislabeling in products, publications, and some publicly available DNA sequences, is discussed in the present work. The last findings in health promoting properties of L. paracasei and the bioactive compounds are described and compared to strains isolated from kefir, providing a special focus on exopolysaccharides as effector molecules. The knowledge of the state of the art of Lacticaseibacillus paracasei from kefir and water kefir can help to understand the contribution of these microorganisms to the health benefits of artisanal beverages as well as to discover new probiotic strains for applications in food industry. Full article

The reported health effects of fermented dairy foods, which are traditionally manufactured in Bulgaria, are connected with their microbial biodiversity. The screening and development of probiotic starters for dairy products with unique properties are based exclusively on the isolation and characterization of lactic acid bacterial (LAB) strains. This study aims to systematically describe the LAB microbial content of artisanal products such as Bulgarian-type yoghurt, white brined cheese, kashkaval, koumiss, kefir, katak, and the Rhodope’s brano mliako. The original technologies for their preparation preserve the valuable microbial content and improve their nutritional and probiotic qualities. This review emphasises the features of LAB starters and the autochthonous microflora, the biochemistry of dairy food production, and the approaches for achieving the fortification of the foods with prebiotics, bioactive peptides (ACE2-inhibitors, bacteriocins, cyclic peptides with antimicrobial activity), immunomodulatory exopolysaccharides, and other metabolites (indol-3-propionic acid, free amino acids, antioxidants, prebiotics) with reported beneficial effects on human health. The link between the microbial content of dairy foods and the healthy human microbiome is highlighted. Full article

Artisanal kefir is a traditional fermented dairy product made using kefir grains. Kefir has documented natural antimicrobial activity and health benefits. A typical kefir microbial community includes lactic acid bacteria (LAB), acetic acid bacteria, and yeast among other species in a symbiotic matrix. In the presented work, the 16S rRNA gene sequencing was used to reveal bacterial populations and elucidate the diversity and abundance of LAB species in international artisanal kefirs from Fusion Tea, Britain, the Caucuses region, Ireland, Lithuania, and South Korea. Bacterial species found in high abundance in most artisanal kefirs included Lactobacillus kefiranofaciens, Lentilactobacillus kefiri,Lactobacillus ultunensis, Lactobacillus apis, Lactobacillus gigeriorum, Gluconobacter morbifer, Acetobacter orleanensis, Acetobacter pasteurianus, Acidocella aluminiidurans, and Lactobacillus helveticus. Some of these bacterial species are LAB that have been reported for their bacteriocin production capabilities and/or health promoting properties. Full article

Kefir, a fermented dairy beverage, exhibits antimicrobial activity due to many metabolic products, including bacteriocins, generated by lactic acid bacteria. In this study, the antimicrobial activities of artisanal kefir products from Fusion Tea (A), Britain (B), Ireland (I), Lithuania (L), the Caucuses region (C), and South Korea (K) were investigated against select foodborne pathogens. Listeria monocytogenes CWD 1198, Salmonella enterica serovar Enteritidis ATCC 13076, Staphylococcus aureus ATCC 25923, and Bacillus cereus ATCC 14579 were inhibited by artisanal kefirs made with kefir grains from diverse origins. Kefirs A, B, and I inhibited all bacterial indicator strains examined at varying levels, except Escherichia coli ATCC 12435 (non-pathogenic, negative control). Kefirs K, L, and C inhibited all indicator strains, except S. aureus ATCC 25923 and E. coli ATCC 12435. Bacteriocins present in artisanal kefirs were determined to be the main antimicrobials in all kefirs examined. Kefir-based antimicrobials are being proposed as promising natural biopreservatives as per the results of the study. Full article