Characterization of an engineered live bacterial therapeutic for the treatment of phenylketonuria in a human gut-on-a-chip

Abstract

Engineered bacteria (synthetic biotics) represent a new class of therapeutics that leverage the tools of synthetic biology. Translational testing strategies are required to predict synthetic biotic function in the human body. Gut-on-a-chip microfluidics technology presents an opportunity to characterize strain function within a simulated human gastrointestinal tract. Here, we apply a human gut-chip model and a synthetic biotic designed for the treatment of phenylketonuria to demonstrate dose-dependent production of a strain-specific biomarker, to describe human tissue responses to the engineered strain, and to show reduced blood phenylalanine accumulation after administration of the engineered strain. Lastly, we show how in vitro gut-chip models can be used to construct mechanistic models of strain activity and recapitulate the behavior of the engineered strain in a non-human primate model. These data demonstrate that gut-chip models, together with mechanistic models, provide a framework to predict the function of candidate strains in vivo.

Microbiota and Colorectal Cancer: From Gut to Bedside

“…The use of the microbiota as direct therapy to tackle cancer and other diseases has also been assessed as a possibility and has shown promising results in recent years ( Nelson et al, 2021 ; Braat et al, 2006 ). With the advent of genetic engineering technologies, it is now possible to use bacteria as a delivery system to selectively release therapeutic compounds into the tumour in vivo ( Zhu et al, 2019 ; Riglar and Silver, 2018 ; Zhou et al, 2018 ; An et al, 2019 ; Chung et al, 2021 ; Chowdhury et al, 2019 ; Frahm et al, 2015 ).…”

Mechanical Strain-Enabled Reconstitution of Dynamic Environment in Organ-on-a-Chip Platforms: A Review

“…Hence, this gut-on-a-chip system can recapitulate the fully functional epithelium monolayer tissue by leveraging the dynamic microenvironment for different studies on the in vitro intestinal model. In fact, the parallel vacuum chamber structure-induced mechanical stretch has been widely used in follow-up gut-on-a-chip and intestine-on-a-chip works [76,77]. and monolayer barrier function.…”

“…Hence, this gut-on-a-chip system can recapitulate the fully functional epithelium monolayer tissue by leveraging the dynamic microenvironment for different studies on the in vitro intestinal model. In fact, the parallel vacuum chamber structure-induced mechanical stretch has been widely used in follow-up gut-on-a-chip and intestine-on-a-chip works [76,77]. While the in vitro artificial gut model was not established from primary cells or stem cells, it has been demonstrated by the same group that the poorly differentiated cell lines could still be qualified to undergo spontaneous villus morphogenesis, elevate mucus production, and improve drug metabolizing activity [78].…”

“…They claimed that bacteria would overgrow without the peristaltic strain, which was similar to the observation in patients with ileus and inflammatory bowel disease. More recently, Nelson et al succeed in demonstrating the predictive ability of the human gut-on-a-chip platform for the characterization of an engineered live bacterial therapeutic [77]. Single bolus application of a synthetic live biotherapeutic, SYN5183 was applied to the gut compartment, resulting in dose-dependent increases in the biomarker, trans-cinnamic acid (TCA), and a corresponding 26.9% decrease in systemic Phe.…”

An engineered bacterial therapeutic lowers urinary oxalate in preclinical models and in silico simulations of enteric hyperoxaluria

“…Moreover, mathematical modeling is a useful tool to translate preclinical evidence of drug action to clinical benefit and has been proven successful in the acceleration of drug development across a wide assortment of therapeutic indications (Milligan et al , 2013 ). The application of mechanistic modeling frameworks to live bacterial therapeutics combining preclinical data of strain activity with prior knowledge of human GI physiology enables the prediction of effects on biomarkers of disease and increased confidence regarding the translational potential of synthetic biotics in patients (Charbonneau et al , 2021 ; Nelson et al , 2021 ).…”