ABSTRACT
Microorganisms exist in diverse communities in and on the human body, where their importance is becoming increasingly better understood and appreciated. Given the preference of certain microbes for specific locations on the body, these niches could be leveraged to engineer microbial therapeutics to treat diseases or maintain host health. Probiotics have been used as dietary supplements for many decades. Many studies have shown (and continue to show) that the composition of the human microbiota is correlated with multiple and diverse health conditions. The probiotics are mostly used as generics and thus are non-specific for different pathogenic organisms. The use of synthetic biology tools along with a good understanding of the virulence factors involved in pathogenesis can offer an alternative, specific treatments. Genetic manipulation of a probiotic strain can modulate the immune system, alter the metabolism of the host, improve stress tolerance and/or survival of the probiotic in the gastrointestinal tract. Engineered probiotic strains also have the ability to sense, record, and respond to their local environments in order to confer beneficial effects to the host. The success of these designed probiotics depends on the availability of genetic tools. Recent advances in molecular and synthetic biology have opened the door for new and emerging applications for engineered probiotics. This chapter focuses on engineered probiotics, their mechanism of action, probiotics which take advantage of the quorum sensing and the use of E. coli as microbial chassis, and potential future prospects for their applications.
