Engineering probiotics to biosynthesize natural substances for microbiome brain research

PROJECT SUMMARY To advance microbiome brain studies the general goals of this collaborative proposal are to provide services to research community by engineering probiotics e g E coli Nissle EcN Bifidobacteria longum Lactobacillus plantarum to biosynthesize various naturally occurring chemicals as prebiotic probiotic conjugates which will be marketed as important laboratory agents to study the effects of natural products on neurological diseases by modulating gut microbiome As a proof of concept EcN that produces high levels of hydroxytryptophan HTP a natural biosynthetic precursor of serotonin will be fed to mice to evaluate its bioavailability pharmacokinetic tolerability modulation of microbiome and toxicity We have recently developed a novel microbial approach for HTP production by rationally engineering a phenylalanine hydroxylase into a tryptophan hydroxylase and reconstituting a novel HTP biosynthetic mechanism in a model microorganism E coli K derivative The proposed research in phase I will focus on Aim testing whether the novel microbial approach for producing high level HTP in the E coli strain BW can be utilized in the probiotic strain EcN HTP EcN and Aim on testing that the HTP EcN has no adverse effects and the produced HTP is biologically available We choose EcN as the host strain because its safety has been well documented and it can directly interact with mucosal dendritic cells in the gut and promote the absorbance of biomolecules biosynthesized by itself Furthermore it can reside in the gut for weeks and realize controlled release and sustained delivery of biosynthesized compounds HGG Research LLC is a company that will develop methods to synthesize various natural compounds in probiotic strains Research by the academic partner currently at the University of Georgia will evaluate the bioavailability modulation of microbiome and toxicity The design of studies by expressing various phytochemicals in different probiotic strains using an inducer free expression system in a mouse model would be the next stage following this STTR project Biosynthesis of natural products by probiotics in gut has several advantages compared to oral feeding of these compounds We believe that the proposed research is innovative and of great significance and represents a frontier in health research metabolic engineering and synthetic biology with implications in biology chemistry and engineering PROJECT NARRATIVE The gut brain axis is now recognized as a regulator of mood cognition pain sleep and eating behavior Probiotics have been used in modulating gut microbiota to prevent and treat a variety of diseases and disorders including those that are associated with the gut brain axis Gut microflora can function as the vectors for generating and delivering various types of naturally occurring beneficial compounds Furthermore natural products have been studied widely for their preventive complementary treatments for various neurological diseases and they can modulate microbiome To advance microbiome brain studies the general goals of this collaborative proposal are to provide services to research community by engineering probiotics e g E coli Nissle EcN Bifidobacteria longum Lactobacillus plantarum to biosynthesize various naturally occurring chemicals as prebiotic probiotic conjugates which will be marketed as important laboratory agents to study the effects of natural products on neurological diseases by modulating gut microbiome The proposed research will lead to the development of food grade genetic tools and techniques that can have much broader applications in engineering many other probiotics which will greatly improve our capability of manipulating probiotics for health related use