Effects of Biofilm Formation on Gastrointestinal Tolerance, Mucoadhesion and Transcriptomic Responses of Probiotics.

Probiotic health benefits may be affected by decreased viability during food storage and gastrointestinal transit. Although microencapsulation is an effective protective strategy, its application to probiotics is limited. Currently, research on probiotic biofilms is expanding, with these biofilms being recognized as the fourth generation of probiotics. This study aimed to investigate the effects of biofilm formation on gastrointestinal tolerance and mucoadhesion of three different probiotics: Li01 ( Li01), (), and (). Biofilm growth was markedly inhibited by low pH and high bile salt concentrations. The formation of biofilms greatly improved the survival of all three strains under simulated gastrointestinal conditions. The biofilms increased intestinal adhesion and surface hydrophobicity in and Li01, while reducing adhesion in due to decreased hydrophobicity. Moreover, transcriptomic analysis of Li01 identified 157 differentially expressed genes, enriched in pathways including ABC transporters, quorum sensing, purine metabolism, arginine biosynthesis, the phosphotransferase system (PTS), RNA polymerase, and the NOD-like receptor signaling pathway. In conclusion, the formation of biofilms enhances gastrointestinal tolerance and intestinal adhesion of probiotics, presenting great applied potential in increasing the efficacy of probiotics.