Exploration of probiotic attributes in lactic acid bacteria isolated from fermented Theobroma cacao L. fruit using in vitro techniques

Lactic Acid Bacteria Strains Isolated from Jerusalem Artichoke (Helianthus tuberosus L.) Tubers as Potential Probiotic Candidates

The search for probiotic candidates is an area that accompanies the world trend of development of novel probiotic strains and new products. In recent years, unconventional sources of potential probiotic bacteria have been studied. Furthermore, there has been an increasing interest in non-dairy and plant-based probiotic foods, currently being considered as a priority for the food industry. The aim of this study was to evaluate the probiotic potential of lactic acid bacteria (LAB) isolated from Jerusalem artichoke tubers. These strains were characterized by in vitro tests for their biochemical and probiotic properties and safety aspects. The results demonstrated that the LAB strains isolated exhibited a survival rate after acid exposure exceeding 90%, maintained viability above 88% under simulated gastrointestinal conditions, and the autoaggregation capacity ranged from 61 to 81%. Additionally, the strains showed no hemolytic activity and were sensitive to antibiotics. The isolates also downregulated the proinflammatory responses and showed antimicrobial activity against E. coli and B. cereus. The bacilli strains showed a high similarity with Lentilactobacillus kosonis and Lentilactobacillus curieae. Hence, these strains revealed potential probiotic in vitro characteristics that position them to be used in plant-based functional food. This strategic exploration of probiotic bacteria sourced from vegetables not only enhances the diversity of available strains-both taxonomically and functionally-but also fosters the development of sustainable, plant-based probiotic applications.

Characterizations of lactic acid bacteria derived from pickles and the effects of fermentation on phenolic compounds in peony flowers

This study aims to characterize lactic acid bacteria (LAB) in pickles and investigate the effect of lactic acid fermentation on phenolic compounds in peony flowers. Six strains of Lactobacillus plantarum and one strain of Weissella identified by 16S rRNA sequencing met the safety standards confirmed by metabolite safety assessment and antibiotic resistance analysis. NPLP12 exhibited excellent fermentation characteristics and its tolerance, adhesion, and antioxidant indicators all demonstrated its potential as probiotics and starter. After fermentation with NPLP12, the content of total phenols (15.2 %) and flavonoids (22.7 %) in the liquid extract of peony flowers was significantly increased, and the antioxidant activity was also enhanced. Ultra Performance Liquid Chromatography Tandem Mass Spectrometry (UPLC-MS/MS) analysis confirmed that apigenin 7-O-glucoside and kaempferol-3-O-glucoside were key synergistic components. This study provides a reference for the screening of peony flower fermentation strains, the utilization of peony flower resources and the development of functional peony flower fermentation beverages.

Exploring the antidiabetic activity of potential probiotic bacteria isolated from traditional fermented beverage

Type 2 Diabetes continues to be one of the major public health issues worldwide without any sustainable cure. The modulation of gut microbiota is believed to be caused by probiotic bacteria and several probiotic strains have previously shown antidiabetic activity. The present study aims to isolate potential probiotic bacteria from traditionally used fermented rice beer of Assam, India and to investigate its anti-hyperglycemic effect. Of the 20 isolated bacterial isolates, 5 isolates showed potential probiotic activities, of which, 2 isolates viz. Bacillus sp. FRB_A(A) and Acetobacter sp. FRB_B(S) showed good in vitro anti-oxidant and anti α-glucosidase activities. Based on the in vitro results, isolate Bacillus sp. FRB_A(A) was further used to evaluate the antidiabetic activity in streptozotocin induced diabetic rat model. After 21 days, the blood glucose level in diabetic rats with probiotic administration significantly lowered from 458.00 ± 46.62 mg/dl to 108.20 ± 6.76 mg/dl (p < 0.001), whereas, in diabetic rats without probiotic remained high (576.20 ± 29.48 mg/dl). On analyzing the endogenous antioxidant profile in various tissues of the experimental rats, reduced lipid peroxidation, glutathione level and superoxide dismutase and glutathione peroxidase activity were observed in probiotic administered rats in comparison to the streptozotocin treated diabetic controls. In conclusion, the bacteria Bacillus sp. FRB_A(A) isolated from fermented rice beer possesses probiotic attributes and exhibits significant anti-hyperglycemic activities.

Evaluation of Potential Probiotic Properties and In Vivo Safety of Lactic Acid Bacteria and Yeast Strains Isolated from Traditional Home-Made Kefir

Probiotics are known for their health-promoting resources and are considered as beneficial microorganisms. The current study focuses on the isolation, and on a complete in vitro and in vivo characterization, of yeast and lactic acid bacteria acquired from traditional homemade kefir in order to assess their potentiality as probiotic candidates. In particular, the isolates Pichia kudriavzevii Y1, Lactococcus lactis subsp. hordniae LAB1 and Lactococcus lactis subsp. lactis LAB2 were subjected to in vitro characterization to evaluate their suitability as probiotics. Resistance to acid and bile salts, auto-aggregation, co-aggregation, hydrophobicity, and biofilm production capability were examined, as well as their antioxidant activity. A safety assessment was also conducted to confirm the non-pathogenic nature of the isolates, with hemolysis assay and antibiotic resistance assessment. Moreover, mortality in the invertebrate model Galleria mellonella was evaluated. Current findings showed that P. kudriavzevii exhibited estimable probiotic properties, placing them as promising candidates for functional foods. Both lactic acid bacteria isolated in this work could be classified as potential probiotics with advantageous traits, including antimicrobial activity against enteric pathogens and good adhesion ability on intestinal cells. This study revealed that homemade kefir could be a beneficial origin of different probiotic microorganisms that may enhance health and wellness.