Novel Probiotic Strains From Honey and Fermented Edible Flowers Mitigate Chronic Cortisol‐Induced Leaky Gut Syndrome in the CaCo2 Cell Model

Chronic stress and elevated cortisol levels can compromise intestinal barrier function, potentially leading to leaky gut syndrome and associated health conditions. The probiotic potential of novel strains isolated from honey and edible flowers was evaluated in the present study. Five strains identified as Lactiplantibacillus plantarum (MP), Enterococcus lactis (PERI), Lactiplantibacillus plantarum (PARI), Lactocasiebacillus rhamnosus (M1A), and Enterococcus nangengnisis (KK) exhibited strong bile salt hydrolase (BSH) activity. Furthermore, these strains produced short-chain fatty acids, including acetic acid (8.0 to 10.0 mM), butyric acid (0.3 to 0.5 mM) and propionic acid (1.8 to 2.5 mM), known to support gut health and immune modulation. Under chronic cortisol exposure, L. rhamnosus (M1A), L. plantarum (BAN), and L. plantarum (PARI) significantly alleviated tight junction disruption, experimentally proven by FITC dextran leakage and gene expression of zona occludin-1 (≤3-fold increase) and cadherin (≤4.36-fold increase) compared to the cortisol-treated CaCo2 cell model. These findings indicate that the novel probiotic strains can enhance intestinal barrier integrity under chronic stress conditions in a model system; however, they warrant further investigation for their potential application in functional foods targeting gut health. PRACTICAL APPLICATIONS: Probiotic consumption improves gut microbiota balance and thereby enhances immune responses. Natural sources, including honey and edible flowers, are gaining attention for having a rich diversity of Lactic acid bacteria, which are known to have probiotic properties. Lactic acid bacterial strains isolated from these sources in the present study showed probiotic activity and produced short-chain fatty acids, supporting gastrointestinal health and immune responses. These strains can be used to develop functional food products for better gut health and overall well-being.