Abstract:
This study delves into the temporal dynamics of bacterial interactions in the gastrointestinal
tract, focusing on how probiotic strains and pathogenic bacteria influence each other and
human health. This research explores adhesion, competitive exclusion, displacement, and inhibition
of selected diarrhoeagenic Escherichia coli (D-EAEC) and potential probiotic strains under various
conditions. Key findings reveal that adhesion is time-dependent, with both D-EAEC K2 and probiotic
L. plantarum FS2 showing increased adhesion over time. Surprisingly, L. plantarum FS2 outperformed
D-EAEC K2 in adhesion and exhibited competitive exclusion and displacement, with inhibition of
adhesion surpassing competitive exclusion. This highlights probiotics’ potential to slow pathogen
attachment when not in competition. Pre-infecting with L. plantarum FS2 before pathogenic infection
effectively inhibited adhesion, indicating probiotics’ ability to prevent pathogen attachment.
Additionally, adhesion correlated strongly with interleukin-8 (IL-8) secretion, linking it to the host’s
inflammatory response. Conversely, IL-8 secretion negatively correlated with trans-epithelial electrical
resistance (TEER), suggesting a connection between tight junction disruption and increased
inflammation. These insights offer valuable knowledge about the temporal dynamics of gut bacteria
interactions and highlight probiotics’ potential in competitive exclusion and inhibiting pathogenic
bacteria, contributing to strategies for maintaining gastrointestinal health and preventing infections.
