# Preclinical Evaluation of Synthetic Biology-Driven Engineered Escherichia coli Nissle 1917 as a Living Therapeutic for Sustained L‑DOPA Delivery

## TL;DR

Scientists engineered a probiotic bacteria to continuously deliver L-DOPA, a treatment for Parkinson's disease, showing promising results in mice.

## Contribution

A novel probiotic strain of Escherichia coli is developed to stably deliver L-DOPA for Parkinson's treatment.

## Key findings

- The engineered bacteria produced up to 12,000 ng/mL L-DOPA in vitro.
- In mice, the bacteria increased brain L-DOPA and dopamine levels by 1- to 2-fold.
- The therapy reduced motor and nonmotor deficits in Parkinson's mouse models better than traditional L-DOPA.

## Abstract

Dopamine deficiency
resulting from nigrostriatal dopaminergic neuronal
damage manifests as extrapyramidal motor symptoms of Parkinson’s
disease (PD). Oral tablet dosing of levodopa, administered 3–4
times a day, remains the standard of care due to its tolerability
and effectiveness; however, it is prone to deleterious side effects,
including off-periods and levodopa-induced dyskinesia after long-term
use. Herein, using synthetic biology approaches, we developed and
systematically evaluated the feasibility of a probiotic-based live-biotherapeutic
system to continuously deliver L-DOPA stably, thereby relieving motor
symptoms. Our data demonstrate that our engineered plasmid-based L-DOPA-expressing Escherichia coli Nissle 1917 probiotic strain (EcN2
LDOPA‑P3) efficiently produced up to 12,000
ng/mL L-DOPA in vitro. In mouse model systems, EcN2
LDOPA‑P3 readily colonized for up to 48 h, achieved
steady-state plasma L-DOPA concentrations, and increased brain L-DOPA
and dopamine levels by 1- to 2-fold. Lastly, EcN2
LDOPA‑P3 significantly diminished motor and nonmotor behavioral deficits
in a mouse model of PD compared to traditional chemical L-DOPA therapy.
These findings support the therapeutic feasibility of a noninvasive,
orally administered bioengineered bacterial therapy for the chronic
delivery of L-DOPA, which may address limitations associated with
current treatment alternatives.