Differential coping strategies exerted by biofilm and planktonic cells of <i>Bacillus subtilis</i> in response to a protozoan predator

The human protozoan parasite <i>Entamoeba histolytica</i> feeds on intestinal microbiota to survive. To enhance the effectiveness of probiotics, we characterized how they respond to amoeba predators. We found that probiotics decrease the expression of biofilm-related genes to avoid predation while simultaneously inducing their stress response and increasing their motility. Our results can provide novel directions for engineering probiotic bacteria to overcome gastrointestinal-associated parasitic diseases. Additionally, it highlights a fundamental mechanism through which bacterial prey can evade predation in the gastrointestinal tract.