Enhancing the gastrointestinal resilience of the candidate probiotic yeast Lachancea thermotolerans DiSVA322 using a symbiotic bee pollen-alginate formulation

This study aimed to optimize symbiotic formulation to enhance the gastrointestinal resilience of the candidate probiotic yeast Lachancea thermotolerans DiSVA322 using adynamic simulation model, DYGIST system which simulates sequential gastric emptying, fractionary intestinal filling, bile removal via dialysis, and coexistence with stabilized human fecal microbiota. In its free form, the novel strain showed a significant viability drop to 15% at the onset of the iliac phase, decreasing further to 2.3% at its completion. However, even at this final 2.3% viability level, the strain successfully satisfied the therapeutic probiotic claim threshold (10 7 –10 8 ) viable cells) compared to the industrial control Saccharomyces cerevisiae var. boulardii (Codex™)and positively showed coexistence and compatibility with the resident microbiota, without altering their microbial equilibrium. To overcome this physiological susceptibility, cell immobilization in 0.5% sodium alginate gel beads was coupled with different functional food carriers (milk, yogurt, and bee pollen). While yogurt maintained cell viability, incorporation with bee pollen as a potential prebiotic matrix delivered the most striking synergistic outcome. This pairing led to a 258% increase in DiSVA322 survival compared to mineral water. Microscopic and chemical kinetics confirmed that yeast metabolic activity drove a progressive breakdown of pollen grains (from 10% to 23%), promoting a targeted release of antioxidant polyphenols that established a protective microenvironment for the yeast cells. Combining encapsulation technology with bee pollen successfully bridges the resilience gap between emerging non- Saccharomyces probiotics and established commercial strains under realistic, dynamic human digestive conditions.