Novel Probiotic Strains From Honey and Fermented Edible Flowers Mitigate Chronic Cortisol-Induced Leaky Gut Syndrome in the CaCo 2 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 CaCo 2 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.