Search Results (40)

This study focuses on the identification of three lactic acid bacteria isolates obtained from traditional Algerian fermented wheat as well as the evaluation of their biological activities, mainly their probiotic, antimicrobial, anti-inflammatory, and antioxidant properties. These isolates were identified through phenotypic and genotypic characterizations. It was found that isolate LB3 was Lactiplantibacillus plantarum, while isolates LB1 and LB2 were identified as Weissella confusa. It was observed that the strains LB1, LB2, and LB3 are capable of maintaining their growth at pH 3.0 and in bile salts after 4 h, with individual survival rates ranging from 41% to 90% depending on the strain. Furthermore, their co-aggregation capacity with Staphylococcus aureus ATCC6528 indicated a percentage higher than 50%. The three strains displayed powerful inhibitory effects against pathogenic bacteria, showing inhibition rates of 5% to 40%. They also exhibited significant anti-inflammatory activity ranging from 20% to 39%. All three lactic acid bacteria (LAB) isolates exhibited significant antioxidant activity. Their intact cells demonstrated a high ability to scavenge DPPH radicals and possessed substantial ferric reducing power, while their intracellular extracts showed high levels of glutathione (GSH). Additionally, they exerted a protective effect against plasma lipid peroxidation, with inhibition rates ranging from 20% to 39%. These findings suggest that these strains possess promising probiotic potential as future therapeutic agents to be used in the development of novel functional fermented foods. Full article

Antibiotic overuse has contributed to the emergence of multidrug-resistant (MDR) bacteria, posing a serious public health threat. Pets may act as reservoirs of MDR bacteria, with the potential to transmit these pathogens to humans. This study aimed to identify probiotic alternatives to antibiotics by isolating and evaluating lactic acid bacteria (LAB) from feline milk. In addition to conventional in vitro assessments such as growth kinetics, adhesion ability, safety, and antipathogenic activity, this study also evaluated the antioxidant capacity and production of beneficial metabolites. Three LAB strains were isolated from feline milk, including two strains of Lactobacillus plantarum (M2 and M3) and one strain of Weissella confusa (M1). Resistance assays revealed that strains M2 and M3 exhibited high survival rates under stress conditions, including exposure to bile salts, acidic environments, artificial intestinal and gastric juice. Notably, strain M3 demonstrated strong auto-aggregation ability (73.39%) and high hydrophobicity toward trichloromethane (62.16%). It was also nonhemolytic and susceptible to various β-lactam antibiotics. Furthermore, strain M3 exhibited potent antimicrobial activity in both co-aggregation and Oxford cup assays. Overall, L. plantarum M3 displayed superior probiotic properties, suggesting its potential as an adjunct or alternative to antibiotics in managing MDR bacterial infections in cats. Full article

High potential is attributed to the concomitant use of probiotics and prebiotics in a single food product, called “synbiotics”, where the prebiotic component distinctly favours the growth and activity of probiotic microbes. This study implemented a detailed comparison between the prebiotic effect of Fructooligosaccharides (FOSs) and Raffinose family oligosaccharides (RFOs) on the viable count of bacteria, hydrolysis into monosaccharides, the biosynthesis of short-chain fatty acids and sensory attributes of soymilk fermented with 1% (v/v) co-cultures of Lacticaseibacillus rhamnosus JCM1136 and Weissella confusa 30082b. The highest viable count of 1.21 × 10⁹ CFU/mL was observed in soymilk with 3% RFOs added as a prebiotic source compared with MRS broth with 3% RFOs (3.21 × 10⁸) and 3% FOS (6.2 × 10⁷ CFU/mL) when replaced against glucose in MRS broth. Raffinose and stachyose were extensively metabolised (4.75 and 1.28-fold decrease, respectively) in 3% RFOs supplemented with soymilk, and there was an increase in glucose, galactose, fructose (2.36, 1.55, 2.76-fold, respectively) in soymilk supplemented with 3% FOS. Synbiotic soymilk with 3% RFOs showed a 99-fold increase in methyl propionate, while the one supplemented with 3% FOS showed an increase in methyl butyrate. The highest acceptability based on the sensory attributes was for soymilk fermented with 2% RFOs + 2% FOS + 2% table sugar + 1% vanillin (7.87 ± 0.52) with high mouth feel, product consistency, taste, and flavour. This study shows that the simultaneous administration of soy with probiotic bacteria and prebiotic oligosaccharides like FOSs and RFOs enhance the synergistic interaction between them, which upgraded the nutritional and sensory quality of synbiotic soymilk. Full article

The biotechnological potential of the lactic acid bacterial genus Weissella has not been fully unearthed. Since Weissella have not been tested against Fusaria and their mycotoxins, newly isolated Weissella confusa strains were characterized and tested for their antifungal capacities on Fusarium plant pathogens. W. confusa BF2 and ML2 successfully inhibited Fusarium verticillioides NCIM 1100, F. verticillioides NCIM 1099, Fusarium graminearum MTCC 2089, and Fusarium oxysporum MTCC 284 in co-cultures. Ethyl acetate extracts of the cell-free culture supernatants (CFCS) of W. confusa also exhibited antifungal activity against the tested fungal cultures. The main mycotoxins of Fusaria were tested against the Weissella isolates. In MRS broth, W. confusa BF2 was resistant to the Fusarium mycotoxins (deoxynivalenol, zearalenone, T2, and fumonisin B1), while the ML2 strain showed 22.1–24.5% growth inhibition. Meanwhile, neither bacterium showed potential in mycotoxin reduction. The study highlighted that W. confusa BF2 and ML2 and their CFCS are suitable for Fusarium growth inhibition, as shown on surface-sterilized peanuts and wheat grains, but not for mycotoxin elimination. Full article

Controlled fermentation carried out by selected starters might enhance the safety, nutritional, and biological profiles of non-dairy fermented products. This research aims to study the biological potential and impact on the human gut microbiota of a novel fermented finger millet-based product. Finger millet (Eleusine coracana), suspended in an aqueous sucrose-based solution, was fermented by Weissella confusa 2LABPT05 and Lactiplantibacillus plantarum 299v (1%, 1:1 ratio (v/v)), at 30 °C/200 rpm in an orbital incubator until pH ≈ 4.5–5.0. Microbial growth, phenolic compounds, antioxidant, and antidiabetic activities were evaluated. In vitro digestion followed by in vitro faecal fermentation were used to study the impact of the fermented plant-based functional beverage (PBFB) on the human gut microbiota. Antidiabetic activity (21% vs. 14%) and total phenolics (244 vs. 181 mg of gallic acid equivalents/kg PBFB) increased with fermentation. The digested fermented PBFB contributed to the increase, over the first 6 h, of the Bifidobacterium’s 16S rRNA gene copy numbers, concomitant with significant release of the acetic, propionic, and butyric short chain fatty acids, and also lactic acid. The novel PBFB has been shown to have antidiabetic potential and bifidogenic effects, and consequently its consumption might positively impact blood glucose levels and the human gut microbiota. Full article

The use of lactic acid bacteria for developing functional foods is increasing for their ability to synthesize beneficial metabolites such as vitamin B (riboflavin, RF) and postbiotic compounds. Here, the spontaneous mutant FS54 B2 was isolated by treatment of the dextran-producing Weissella confusa FS54 strain with roseoflavin. FS54 B2 overproduced RF (4.9 mg/L) in synthetic medium. The FMN riboswitch is responsible for the regulation of RF biosynthesis, and sequencing of the coding DNA revealed that FS54 B2 carries the G131U mutation. FS54 B2 retained the capacity of FS54 to synthesize high levels of dextran (3.8 g/L) in synthetic medium. The fermentation capacities of the two Weissella strains was tested in commercial oat-, soy- and rice-based beverages. The best substrate for FS54 B2 was the oat-based drink, in which, after fermentation, the following were detected: RF (2.4 mg/L), dextran (5.3 mg/L), potential prebiotics (oligosaccharides (panose (5.1 g/L), isomaltose (753 mg/L) and isomaltotriose (454 mg/L)) and the antioxidant mannitol (16.3 g/L). pH-lowering ability and cell viability after one month of storage period were confirmed. As far as we know, this is the first time that an RF-overproducing W. confusa strain has been isolated, characterized and tested for its potential use in the development of functional beverages. Full article

The impact of wheat sourdough inoculated with a promising lactic acid bacterium Weissella confusa V20, isolated from a Tunisian desert plant, on the quality characteristics of sourdough and bread as well as on acrylamide formation was evaluated. W. confusa V20 sourdough (SWc) did not provide high final acidity and could effectively metabolize sucrose, resulting in significant (p < 0.05) increases in glucose (44.5%) and fructose (84.2%) levels. A substantial decrease (p < 0.05) in free asparagine was observed upon fermentation, reducing from 16 ± 0.9 mg/100 g dry weight (d.w.) in the control dough with baker’s yeast (DBB) to 9.9 ± 0.4 mg/100 g d.w. in the dough inoculated with W. confusa V20 sourdough (DWc) and to 14.2 ± 0.2 mg/100 g d.w. in the dough produced with spontaneous sourdough (DSS). To improve the texture and flavor of the bread, the sourdough process should be further optimized in a strain-specific approach. V20 sourdough was more effective in enhancing the quality of the dough and bread compared to sourdough fermented with yeast. W. confusa V20 proved to be highly effective in reducing acrylamide levels, achieving a significant 62% decrease compared to the control. Full article

Background: Weissella confusa is a member of the lactic acid bacterium group commonly found in many salt-fermented foods. Strains of W. confusa isolated from high-salinity environments have been shown to tolerate salt stress to some extent. However, the specific responses and mechanisms of W. confusa under salt stress are not fully understood. Methods: To study the effect of NaCl stress on W. confusa, growth performance and metabolite profiles of the strains were compared between a NaCl-free group and a 35% NaCl-treated group. Growth performance was assessed by measuring viable cell counts and examining the cells using scanning electron microscopy (SEM). Intracellular and extracellular metabolites were analyzed by non-targeted metabolomics based on liquid chromatography-mass spectrometry (LC-MS). Results: It was found that the viable cell count of W. confusa decreased with increasing salinity, and cells could survive even in saturated saline (35%) medium for 24 h. When exposed to 35% NaCl, W. confusa cells exhibited surface pores and protein leakage. Based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, 42 different metabolites were identified in the cells and 18 different metabolites in the culture medium. These different metabolites were mainly involved in amino acid metabolism, carbohydrate metabolism, and nucleotide metabolism. In addition, salt-exposed cells exhibited higher levels of intracellular ectoine and lactose, whose precursors, such as aspartate, L-2,4-diaminobutanoate, and galactinol, were reduced in the culture medium. Conclusions: This study provides insight into the metabolic responses of W. confusa under salt stress, revealing its ability to maintain viability and alter metabolism in response to high NaCl concentrations. Key metabolites such as ectoine and lactose, as well as changes in amino acid and nucleotide metabolism, may contribute to its tolerance to salt. These findings may improve our understanding of the bacterium’s survival mechanisms and have potential applications in food fermentation and biotechnology. Full article

The importance of the valorization of industrial by-products has led to increasing research into their reuse. In this research, the innovative by-product okara oat flour, derived from the vegetable beverage industry, was studied. Oat okara sourdough was also produced and evaluated. The microbiological identification and typing involved bacterial and yeast isolates from both flour and sourdough. Untargeted metabolomics allowed the identification of biomarkers of fermented flour, such as phenolic classes, post-fermentation metabolites, fatty acids, and amino acids. The microorganisms most found were Weissella confusa, Enterococcus faecium, Pediococcus pentosaceus, and Pichia kudriavzevii, while Saccharomyces cerevisiae appeared only at the end of the sourdough’s back-slopping. Untargeted metabolomics identified a total of 539 metabolites, including phenolic compounds, lipids, amino acids, and organic acids. An increase in polyphenols released from the food matrix was detected, likely because of the higher bio-accessibility of phenolic metabolites promoted by microbial fermentation. Fermentation led to an increase in isoferulic acid, p-coumaric acid, sinapic acid, and a decrease in amino acids, which can be attributed to the metabolism of lactic acid bacteria. Some key markers of the fermentation process of both lactic acid bacteria and yeast were also measured, including organic acids (lactate, succinate, and propionate derivatives) and flavor compounds (e.g., diacetyl). Two bioactive compounds, such as gamma-aminobutyric acid and 3-phenyl-lactic acid had accumulated at the end of fermentation. Taken together, our findings showed that oat okara flour can be considered an excellent raw material for formulating more sustainable and functional foods due to fermentation promoted by autochthonous microbiota. Full article

The role of lipopolysaccharide (LPS) in the development of diseases is clear, but the specific mechanisms remain poorly understood. This study aimed to investigate the microbiome aberrations in the guts of mice against the background of LPS, as well as the anti-inflammatory effect of probiotic supplementation with Lactobacillus plantarum from the gut, a mix of commercial probiotic lactic acid bacteria, and Weissella confusa isolated from milk using next-generation sequencing. LPS injections were found to induce inflammatory changes in the intestinal mucosa. These morphological changes were accompanied by a shift in the microbiota. We found no significant changes in the microbiome with probiotic supplementation compared to the LPS group. However, when Lactobacillus plantarum and a mix of commercial probiotic lactic acid bacteria were used, the intestinal mucosa was restored. Weissella confusa did not contribute to the morphological changes of the intestinal wall or the microbiome. Changes in the microbiome were observed with probiotic supplementation of Lactobacillus plantarum and a mix of commercial probiotic lactic acid bacteria compared to the control group. In addition, when Lactobacillus plantarum was used, we observed a decrease in the enrichment of the homocysteine and cysteine interconversion pathways with an increase in the L-histidine degradation pathway. Full article

Growing interest in probiotics has spurred research into their health benefits for hosts. This study aimed to evaluate the probiotic properties, especially antibacterial activities and the safety of two Weissella confusa strains, W1 and W2, isolated from Khao-Mahk by describing their phenotypes and genotypes through phenotypic assays and whole genome sequencing. In vitro experiments demonstrated that both strains exhibited robust survival under gastric and intestinal conditions, such as in the presence of low pH, bile salt, pepsin, and pancreatin, indicating their favorable gut colonization traits. Additionally, both strains showed auto-aggregation and strong adherence to Caco2 cells, with adhesion rates of 86.86 ± 1.94% for W1 and 94.74 ± 2.29% for W2. These high adherence rates may be attributed to the significant exopolysaccharide (EPS) production observed in both strains. Moreover, they exerted remarkable antimicrobial activities against Stenotrophomonas maltophilia, Salmonella enterica serotype Typhi, Vibrio cholerae, and Acinetobacter baumannii, along with an absence of hemolytic activities and antibiotic resistance, underscoring their safety for probiotic application. Genomic analysis corroborated these findings, revealing genes related to probiotic traits, including EPS clusters, stress responses, adaptive immunity, and antimicrobial activity. Importantly, no transferable antibiotic-resistance genes or virulence genes were detected. This comprehensive characterization supports the candidacy of W1 and W2 as probiotics, offering substantial potential for promoting health and combating bacterial infections. Full article

Background: WCFA19 (Weissella confusa WIKIM51), found during the fermentation of kimchi, is known for its inhibitory effects on body weight and body fat. This study looked at the impact of WCFA19 isolated from dandelion kimchi on weight loss in overweight and obese adults that are otherwise healthy. Methods: This study was conducted as a multicenter, double-blind, randomized, placebo-controlled study with 104 overweight and obese subjects. Subjects were randomized evenly into the test group (WCFA19, 500 mg, n = 40) or control group (n = 34) for 12 weeks from 14 June 2021 to 24 December 2021. Effects were based on DEXA to measure changes in body fat mass and percentage. Results: Among the 74 subjects analyzed, WCFA19 oral supplementation for 12 weeks resulted in a significant decrease in body fat mass of 633.38 ± 1396.17 g (p = 0.0066) in overweight and obese individuals in the experimental group. The control group showed an increase of 59.10 ± 1120.57 g (p = 0.7604), indicating a statistically significant difference between the two groups. There was also a statistically significant difference (p = 0.0448) in the change in body fat percentage, with a decrease of 0.41 ± 1.22% (p = 0.0424) in the experimental group and an increase of 0.17 ± 1.21% (p = 0.4078) in the control group. No significant adverse events were reported. Conclusions: Oral supplementation of 500 mg of WCFA19 for 12 weeks is associated with a decrease in body weight, particularly in body fat mass and percentage. Full article

Vulvovaginal candidiasis (VVC) is a genital infection caused by Candida albicans (C. albicans). Weissella confusa WIKIM51 (Wilac D001) is known to be detected in dandelion kimchi, produce lactic acid, and have an anti−inflammatory ability; however, its diverse antifungal effects have not been studied. Here, we investigated the antifungal effect of Wilac D001 in C. albicans compared to Lactobacillus species on vaginal epithelial cells (VECs). To test the antifungal ability of Wilac D001 against C. albicans on VECs, an adhesion test, pro-inflammatory cytokines (interleukin (IL)-6 and IL-8) analysis, and a disk diffusion test were performed. The acid tolerance test was conducted to investigate the viability of Wilac D001 in various acidic conditions. Lactobacillus reuteri (L. reuteri) and L. rhamnosus were used as positive controls. Wilac D001 showed the capacity to inhibit the colonization of C. albicans by adhering to VECs, with an inhibitory effect similar to that of positive controls. Both pro−inflammatory cytokines including IL−6 and IL−8 concentrations were significantly decreased when Wilac D001 was treated on C. albicans-infected VECs, respectively (p < 0.001). The result of the disk diffusion test indicates that the inhibitory ability of Wilac D001 is comparable to L. reuteri and L. rhamnosus on agar plates infected with C. albicans. Our results demonstrate that Weissella confusa WIKIM51 has antifungal effects against VECs infected by C. albicans. Full article

Context and Objectives: There is an urgent need for a dietary shift towards an increased consumption of plant protein foods. However, some nutritional and sensory challenges are associated with whole-meal grains and pulses. Fermentation is a promising technology for reducing anti-nutrients, increasing protein digestibility, and reducing starch digestibility in plant-based matrices. This study aimed to evaluate the impact of different fermentation conditions using different bacteria on the nutritional composition of grains and pulses. Methods: Milled wheat, buckwheat, and chickpeas were fermented using different bacteria or combinations of bacteria, i.e., Lactobacillus delbrueckii + Streptococcus thermophilus (Vega), Lacticaseibacillus rhamnosus (Lrham), Leuconostoc pseudomesenteroides (Lpseu), Weissella confusa alone (Wcon) or combined with Lactococcus lactis (Wcon + Lac), or Pediococcus pentosaceus (Wcon + Pen), for 24 or 48 h. Protein hydrolysis and protein and starch digestibility were measured using the O-phtaldialdehyde and Infogest methods, respectively. Starch digestibility was evaluated using the Englyst method. Dietary fibers (DF) were quantified. Results: In buckwheat, all fermentation conditions increased protein hydrolysis, especially Vega. In chickpeas, Lrham and Wcon, alone and in combination, increased protein hydrolysis. In wheat, fermentation did not increase protein hydrolysis. Protein digestibility increased only with Wcon + Pen in buckwheat. For chickpeas and wheat, fermentation did not increase protein hydrolysis, and it was lowest with Lpseu in both cases. Lpseu, Wcon + Lac, and Wcon + Pen led to increased DF in buckwheat, especially soluble high-molecular-weight (HMW) buckwheat (dextran formation). In chickpeas, no increase in DF content was observed due to the hydrolysis of oligosaccharides, but soluble HMW DF increased with Lpseu, Wcon + Lac, and Wcon + Pen (dextran formation). No significant change was observed for wheat DF. The starch hydrolysis index (HI) increased with Lrham over 48 h and Lpseu over 24 h but decreased with Wcon + Lac over 24 h in buckwheat. In chickpeas, HI was reduced in all conditions, the lowest values being with Wcon + Pen and Wcon + Lac. In wheat, HI increased with Lrham over 48 h and decreased with Wcon + Pen. Conclusions: The impact of the fermentation conditions tested differed depending on the grains. Some conditions improved the nutritional characteristics of these grains. These results show promising effects concerning the nutritional quality of grains, which need to be confirmed in finished products. Full article

Lactic acid bacteria (LAB) produce important metabolites during fermentation processes, such as exopolysaccharides (EPS), which represent powerful natural antioxidants. On the other hand, H. sabdariffa L. anthocyanin extracts protect LAB and support their development. This study uncovers for the first time, the antioxidant profile of Weissella confusa PP29 probiotic media and focuses on elevating its impressive antioxidant attributes by synergistically integrating H. sabdariffa L. anthocyanin extract. The multifaceted potential of this innovative approach is explored and the results are remarkable, allowing us to understand the protective capacity of the fermented product on the intestinal mucosa. The total phenolic content was much lower at the end of the fermentation process compared to the initial amount, confirming their LAB processing. The DPPH radical scavenging and FRAP of the fermented products were higher compared to ascorbic acid and antioxidant extracts, while superoxide anion radical scavenging and lipid peroxidation inhibitory activity were comparable to that of ascorbic acid. The antioxidant properties of the fermented products were correlated with the initial inoculum and anthocyanin concentrations. All these properties were preserved for 6 months, demonstrating the promising efficacy of this enriched medium, underlining its potential as a complex functional food with enhanced health benefits. Full article