Non-dairy probiotic formulations are gaining attention due to their health benefits, but it is essential to assess their ability to maintain probiotic viability while ensuring sensory acceptance, which may be achieved by the incorporation of fruit. This study evaluated the effect of pitaya pulp on probiotic viability, post-acidification, color, total phenolic compounds, and sensory characteristics of a cashew nut extract-based probiotic fermented beverage. Cashew nut extract was supplemented with 5% (B05) and 10% (B10) pitaya pulp and fermented by Streptococcus thermophilus and Lacticaseibacillus casei BGP93. The control (BC) contained no pulp. Pitaya pulp did not influence pH, titratable acidity, or probiotic counts, which ranged from 7.15 to 7.83 log CFU mL-1. However, it affected color parameters: treatments with pitaya pulp showed L values ∼12% and b* values 52%-73.7% lower than BC, while a* values were higher in B05 and B10, respectively, compared to BC. It also reduced phenolic compounds after 28 days (208.66, 124.70, and 134.50µg EAG g-1 in BC, B05, and B10, respectively). Pitaya pulp enhanced appearance, flavor, overall acceptance, and purchase intention, with B05 achieving the highest scores. Its addition is a promising approach for developing probiotic plant-based fermented beverages.

Diarrhea, a common gastrointestinal disorder, is often exacerbated by conventional antibiotic treatments that disrupt gut microbiota, necessitating the exploration of Lactic acid bacteria (LAB) alternatives. This study investigates the therapeutic potential and mechanisms of Streptococcus thermophilus NCU074001 (ST) in a rat model of PEG3350-induced osmotic diarrhea. ST treatment mitigated diarrheal symptoms and improved key markers of intestinal health by acting as a key modulator of the gut ecosystem. Its efficacy was driven by balancing immune responses via elevated IL-10 and suppressed pro-inflammatory cytokines (IL-6, IL-1β, TNF-α, IFN-γ). Furthermore, ST reinforced the intestinal barrier by upregulating MUC2 expression and reshaping gut microbial ecology by suppressing certain genera (Bacteroides and Anaerofilum) while enriching others (Lactobacillus, Akkermansia, Phascolarctobacterium, and Parabacteroides). This taxonomic restoration was accompanied by a functional metabolic shift, characterized by increased production of short-chain fatty acids (acetate and butyrate) and a targeted modulation of tryptophan metabolism that enhanced the production of anti-inflammatory indole derivatives. Correlation analyses suggested potential links between ST-mediated microbiota remodeling and barrier strengthening and immunomodulation. Collectively, these results indicate that ST functions as a promising probiotic integrating immunomodulation, microbiota restoration, and metabolic reprogramming to alleviate diarrhea, and thus presents a promising therapeutic alternative to conventional antibiotics.

Abstract Radiation resistance in Deinococcus requires an SOS-independent response mechanism, controlled by M78 family (COG2856) metallopeptidase IrrE and XRE family transcriptional repressor DdrO, to induce expression of DNA repair genes after exposure to radiation. DdrO must form dimers to bind target DNA sites. IrrE inactivates DdrO by cleaving the C-terminal dimerization domain of DdrO. However, the molecular basis of the interaction between IrrE and DdrO is still unknown. Here, we showed that IrrE is monomeric in solution and forms heterodimers with DdrO, with the N-terminal DNA-binding domain of DdrO contributing to the interaction. We further revealed that the initially isolated radiation-sensitive irrE mutant strain encodes an oxidation-sensitive IrrE protein affected in DdrO cleavage. Predicted COG2856/XRE regulatory protein pairs are present in many environmental, pathogenic, and industrial bacteria. Single-stranded DNA enhanced the cleavage activity of IrrE from Deinococcus as well as from closely related Marinithermus and Oceanithermus species, but not of the distant homologs ImmA from Bacillus subtilis and Rir from Streptococcus thermophilus. The formation of a heterotrimer containing IrrE, DdrO and single-stranded DNA was also demonstrated. Together, these findings provide new insights into the molecular interplay between the key regulators IrrE and DdrO.

BackgroundSoy protein is a popular plant-based protein source, but is nutritionally limited by its incomplete essential amino acid profile and lower bioavailability relative to animal proteins. Emerging evidence suggests that probiotics may improve the absorption of amino acids from plant proteins.MethodsOur research evaluated the ability of Streptococcus thermophilus ST4 to improve the soy protein nutritional quality by increasing the bioavailability of essential amino acids, using in vitro digestion models, as well as animal experiments.ResultsAfter 4 h, supplementation with S. thermophilus ST4 increased amino acid concentrations in vitro. Total amino acids rose by up to 96.9%, essential amino acids by 69.1%, and non-essential amino acids by 124.4%. Afterward, rats fed either a standard or high-protein diet received S. thermophilus ST4 at doses of 1 × 107 or 1 × 109 CFU/day. High-dose treatment significantly elevated serum total amino acids by 29.7–32.4% and essential amino acids by 37.7–43.2% (p < 0.01). Postprandial analysis further confirmed a 62.0% increase in essential amino acids in the high-protein group following probiotic supplementation.ConclusionS. thermophilus ST4 supplementation improved the nutritional quality of soy protein by enhancing essential amino acid bioavailability. These findings support its application as a probiotic for improving plant-based protein utilization, offering a practical dietary strategy to address amino acid limitations in vegetarian and high-protein diets.

Structural, genomic and phenotypic analysis of exopolysaccharide produced by Streptococcus thermophilus ST65.

Streptococcus thermophilus alleviates fatty liver disease by regulating gut microbiota, lipid metabolism, and inflammation.

Dairy environment and seasons affect the microbiome of a traditional artisanal cheese.

Dynamics of thermophilic starters in PDO Comté cheese: Insights from viability qPCR.

Streptococcus suis is a major pig pathogen with zoonotic potential, posing an occupational risk to farmers and meat handlers. We characterized 110 S. suis strains from diseased pigs in Ireland (2005-2022) using whole-genome sequencing to investigate population structure and phage-host dynamics. We identified 15 distinct serotypes, with serotypes 9 and 2 being the most dominant. In silico multi-locus sequence typing revealed high diversity within the collection, identifying several sequence types (STs), including 26 novel STs. Investigation of strain-level genomic clustering using PopPUNK against global S. suis genomes showed that the Irish isolates were phylogenetically dispersed across the broader global S. suis population rather than clustering in a single clonal group. The majority of Irish isolates fall within the ten established pathogenic lineages, including the highly virulent zoonotic lineage 1. A locally persistent clonal lineage was identified among Irish isolates, showing minimal genetic variation over a decade.Prophage analysis revealed novel viral taxa that were interspersed among known streptococcal phages, rather than clustering distinctly. Restriction-modification systems were the predominant anti-viral defence systems identified across genomes. CRISPR-Cas systems were present in limited strains but showed substantial targeting bias toward full-length prophages, indicating ongoing phage pressure. CRISPR spacers matched non-S. suis streptococcal phages, and phylogenomic analysis revealed that Vansinderenvirus phages clustered with S. suis rather than other Streptococcus thermophilus phages, suggesting evolutionary connections between phage lineages infecting different streptococci.This study presents the first comprehensive genomic characterization of S. suis in Ireland, revealing a diverse population with significant implications for animal and human health.

Multilayered characterization of sour cream fermentation: Effects of cream origin and fermentation time on microbiota, lipid transformation, and aroma compounds.

Multiomics analysis of a novel American raw milk cheese (Cornerstone) and the effect of production and aging location.

Ayran, a popular fermented dairy product in Türkiye, the Balkans and the Middle East, is commonly made by incorporating salt and water into yoghurt. Viscosity and rheological properties are key in determining the quality properties of ayran drinks. This study is aimed to determine the effect of the most available culture (whether exopolysaccharide (EPS)-producing or not), which is globally marketed, on ayran rheology, viscosity, microstructure, and sensory properties. Four ayran treatments were produced as follows: T1 (ayran made using classic yoghurt culture, Streptococcus thermophilus and L. delbrueckii subsp. bulgaricus); T2: ayran made using ABT-5 culture (L. acidophilus, Bifidobacterium bifidum and S. thermophilus); T3: ayran manufactured by EPS-producing culture (L. delbrueckii subsp. bulgaricus and S. thermophilus); and T4: ayran made using EPS-producing culture + Bifidobacterium Animalis subsp. lactis BB12. Ayran samples were analyzed for rheology, viscosity, microstructure, serum separation, and sensory properties. Unlike T2 and T1, the ayran sample T4 recorded the highest viscosity, the lowest flow behaviour, and the lowest serum separation. Sensory analysis indicated that all ayran samples were found acceptable by the panellists, and T3 followed by T4 gained the highest scores over the cold storage period. Therefore, using EPS-producing strains could be a successful and promising strategy to produce ayran with enhanced quality attributes.

Aim: The benefit of topical application of probiotics on pain and itching associated with skin disorders has become an increasingly intriguing topic in recent years. These effects are mainly associated with the anti-inflammatory activity of probiotics. Given the crucial role of the endocannabinoid system (ECS) in skin pathophysiology, here, the ability of Streptococcus thermophilus was evaluated, in comparison with Lactobacillus acidophilus, to inhibit two enzymes involved in endocannabinoid (eCB) degradation: fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL). Methods: Bacterial lysates were obtained from both probiotics. FAAH and MAGL activities were assayed using fluorometric and colorimetric methods. The effect of probiotic lysates on FAAH and MAGL activities was also evaluated on human keratinocytes stimulated with lipopolysaccharide (LPS). Results: S. thermophilus inhibited both FAAH and MAGL, although to varying extents. In comparison, L. acidophilus had a minimal effect on FAAH and did not influence MAGL activity. Conclusions: Although preliminary, our findings suggest that S. thermophilus may exert both potential analgesic and anti-inflammatory effects by modulating the ECS and reducing the degradation of EC, known to play a key role in immune regulation and inflammation. Results presented confirm the selective actions of probiotics and propose a novel mechanism that may contribute to the beneficial effects of S. thermophilus in alleviating signs and symptoms associated with inflammatory skin conditions. Our evidence shows significant inhibitory activity of S. thermophilus on FAAH and MAGL activity, suggesting its ability to influence skin conditions by modulating ECS and preventing the eCB degradation.

Colorectal cancer (CRC) has a high mortality rate worldwide. Oral and intestinal microbiota members may have an effect on gastrointestinal tumors’ pathogenesis, particularly in CRC. Designed as a pilot study, this study’s aim was to investigate the relationship between CRC and oral microbiota and to identify potential biomarkers for CRC diagnosis. Saliva samples were collected from recently diagnosed CRC patients (n = 14) and healthy controls (n = 14) between March 2023 and December 2023. Microbiota (16S rRNA) analyses were conducted on these saliva samples using a next-generation sequencing method. Phylogenetic analyses, including alpha diversity, principal component analysis (PCA), principal coordinate analysis (PCoA), beta diversity, biomarker, and phenotype analyses, were conducted using the Qiime2 (Quantitative Insights Into Microbial Ecology) platform. Alpha diversity indices (Shannon: p = 0.78, Cho1: p = 0.28, Simpson: p = 0.81) showed no significant difference between CRC and control groups. Beta diversity analysis using Bray–Curtis PCoA indicated significant differences in the microbial community between the two groups (p = 0.003). Examination of OTU distributions revealed that the Mycoplasmatota phylum was undetectable in the oral microbiota of healthy controls but was significantly elevated in CRC patients (CRC: 0.13 ± 0.30, Control: 0.00 ± 0.00, p &lt; 0.05). Additionally, Metamycoplasma salivarium, Bacteroides intestinalis, and Pseudoprevotella muciniphila were undetectable in healthy controls but significantly more prevalent in CRC patients (p &lt; 0.05 for all three species). LEfSe analysis identified eight species with an LDA score &gt; 2, Granulicatella adiacens, Streptococcus thermophilus, Streptococcus gwangjuense, Capnocytophaga sp. FDAARGOS_737, Capnocytophaga gingivalis, Granulicatella elegans, Bacteroides intestinalis, and Pseudoprevotella muciniphila, as potential biomarkers. The results of this study contribute critical evidence of the role of oral microbiota in the pathogenesis of colorectal cancer. Alterations in the microbiota suggest potential biomarkers in understanding the biological mechanisms underlying CRC and developing diagnostic and therapeutic strategies.

The aim of the current study was to investigate the effects of the addition of inulin to yoghurt produced with fat-free milk on the viability of bacteria (Lactobacillus acidophilus), sensory quality, and physical properties. Inulin was added at four different percentages to yoghurts (0%; IN0, 4%; IN4, 8%; IN8, and 12%; IN12). Yoghurts were produced with fat-free milk, inulin and starter cultures containing Lactobacillus acidophilus, Lactobacillus delbrueckii ssp bulgaricus, Bifidobacterium lactis and Streptococcus thermophilus. Viscosity, pH, bacterial counting (Lactobacillus acidophilus) and sensory evaluation were performed. Also, the sensory evaluation was performed as single-blind in terms of appearance, flavor, smell, color, creaminess, texture and consistency with 20 trained panelists. The addition of inulin increased the viscosity (p

ABSTRACT Moringa oleifera has a greater nutritional value due to the different parts of this tree being used as rich sources of vitamins, minerals, and amino acids. At the same time, yogurt is considered to have healthful properties because of its probiotic ability, helping to maintain the balance of gut microbiota. The aim of the present investigation is to assess the influence of the addition of MOFE on the fermentation behavior and product quality of yogurts made by standard yogurt starter cultures, consisting of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus. It was also done to study the physicochemical characteristics and storage stability of the enriched yogurt. Incubation time and extract concentration were optimized using Response Surface Methodology (RSM), based on multiple responses of titratable acidity, pH, protein, antioxidant activity, total phenolic content, and total flavonoid content. Sensory evaluation revealed that there is no significant difference in the enriched and control yogurts in terms of appearance and texture, but the enriched yogurt had a better flavor and overall acceptability.

The valorization of food processing by-products is a key strategy for advancing sustainability in the agri-food sector. This study developed a fermented milk product incorporating tomato powder (TP) obtained from surplus tomatoes not meeting retail appearance standards. Four yogurt formulations were prepared containing TP (2% and 4%, w/v) and two controls with skim milk powder adjusted to equivalent total solids. Samples were inoculated with a commercial starter culture and fermented at 42 °C to a final pH of 4.6. TP addition did not hinder fermentation but altered acidification kinetics, as the 4% TP yogurt exhibited a faster initiation (Tm ≈ 80 vs. 120 min in the control) yet a slower rate of pH decline (Vmax = 0.009 vs. 0.019 pH units/min). TP-fortified yogurts exhibited higher water holding capacity (98% vs. 83%), increased firmness (87 g vs. 47 g), and substantially elevated viscosity (63,000–68,000 mPa·s) while lycopene enrichment enhanced color attributes. Viable counts of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus remained within typical ranges (~6.8 and ~4.9 log CFU/g, respectively, after 24 h), confirming that TP did not compromise microbial activity. Overall, incorporating TP improved structural and functional properties while simultaneously providing tomato-derived antioxidants and promoting a sustainable, circular utilization of surplus tomato streams in fermented dairy products.

Off-odors produced by volatile compounds remain a major barrier to consumer acceptance of plant-based proteins. This study presents a novel two-stage fermentation strategy to effectively reduce undesirable volatiles in eight plant proteins. A sequential fermentation process was developed using Lactobacillus plantarum in Stage 1 and a traditional yogurt culture, Streptococcus thermophilus, Lactobacillus delbrueckii subsp. Bulgaricus and Lactobacillus acidophilus, in Stage 2. This method was applied to solutions of 9% soy, pea, chickpea, mung bean, faba bean, rice, barley-rice, and hemp proteins. Volatile profiles were analyzed via Selected Ion Flow Tube Mass Spectrometry (SIFT-MS) and sensory evaluation before and after fermentation. The two-stage fermentation resulted in significant deodorization, with 95–99% reduction in key odorants such as hexanal, 2-pentylfuran, methoxypyrazines, and sulfur compounds across all proteins. The sequential approach significantly outperformed a one-stage fermentation. Allulose enhanced L. plantarum activity while strawberry preserves supported traditional yogurt culture performance. Non-fermentable additives such as pectin, xanthan gum, and oil had minimal effects on volatiles. The proposed fermentation method offers an effective, scalable, and clean-label solution for mitigating off-odors in plant-based proteins. By leveraging microbial metabolism and formulation synergies, this strategy provides a foundation for developing more palatable plant-based dairy alternatives.

Introduction. Dental caries is one of the most prevalent dental diseases. The primary cause of this pathology is a disruption in the species composition of the oral microbiota. The main causative agent of caries is the bacterium Streptococcus mutans, which begins to dominate the pellicle of the teeth among representatives of its genus, secreting lactic acid that destroys the integrity of the enamel. The attachment of pathogenic microorganisms to dental plaque occurs, as with representatives of the normal flora, through proteins – lectins. This creates a prospect for introducing non-pathogenic, non-acid-producing microorganisms into the oral microbiome by artificially incorporating them into the pellicular microflora. The aim of this research is to develop a method for incorporating non-acid-producing microorganisms into the oral microbiome, based on the co-flocculation of yeasts and streptococci. Materials and methods. The yeast strains Saccharomyces cerevisiae I-224 and Saccharomyces boulardii were selected as non-acid-producing microorganisms. Streptococcus thermophilus var. lactis was used as a producer of the extracellular exp polysaccharide matrix for the common biofilm. Yeast biomass was cultivated in sterile grape must, while streptococcal biomass was grown in liquid YPD medium at 26°C for five days. Following separate cultivation of the lactic streptococcus and the wine yeasts, the cultures were decalcified via centrifugation at 4,000 rpm and treatment of the sediment with a 0.3 mol/l potassium oxalate solution. The precipitated microbial biomass was combined and subjected to flocculation by adding a 1.0% calcium chloride solution. The efficiency of co-flocculate formation was determined microscopically at a 900× magnification after staining the specimen with methylene blue. Results. The yeast Saccharomyces cerevisiae I-224 actively integrated into the common polysaccharide matrix, as evidenced by the clearing of the space around the co-flocculate and the absence of free streptococcal and yeast cells. The weakly flocculating probiotic yeast Saccharomyces boulardii scarcely formed unified flocculates with the bacteria. Discussion and conclusion. An original method has been developed for the creation of interspecies conglomerates of bacteria and yeasts united by a common exopolysaccharide matrix. This method opens the prospect of creating an oral probiotic that reduces the acid load on tooth enamel, as it allows for the partial replacement of acid-producing bacteria with agents of alcoholic fermentation.

Abstract Prebiotics are a category of nutrients susceptible to degradation by the human intestinal microflora. Probiotics possess the ability to metabolise and convert prebiotics into organic acids that benefit human health by interacting with the local intestinal microenvironment. A combination of fructooligosaccharides, isomaltooligosaccharides, and inulin in a ratio of 2:1:3, with an addition ratio of 40%, was selected. The ratio of probiotics was fine-tuned using an orthogonal test and the simulated gastric juice method to determine the optimal composition: 0.3 g of Streptococcus thermophilus , 0.5 g of Lactobacillus acidophilus , 0.5 g of Lactobacillus plantarum , 0.4 g of Lactobacillus rhamnosus , and 0.3 g of Lactobacillus bulgaricus in a 20 g product system. Subsequently, the influence of temperature on the product was assessed, and the shelf life of the product under varying temperatures was calculated. Stored at 4 °C, the product lasted for 13 months, indicating effective preservation capabilities under these conditions.