Modulating Residence Time and Biogeography of Engineered Probiotics

The benefits of probiotic microbes have been studied for decades with steadily increasing demand in food processing, biochemical, and biomedical applications. While the identification of new probiotics, and elucidating the molecular mechanisms of health-promoting activities comprise the bulk of prior investigations, engineering strains to enhance and expand their potential uses has come to the forefront in recent years. This chapter reviews current key efforts in modulating probiotic residence time and targeting region specificity in the gastrointestinal tract by highlighting probiotic delivery and survival methods (encapsulation and biofilms) as well as controlling adhesion and colonization tactics (expressing adhesion-promoting factors and metabolic niche engineering). This discussion also reviews foundational concepts such as polymer materials and encapsulation strategies, mucus adhesion mechanisms in probiotics, and methods for quantifying adhesion.