Engineered probiotics block arsenite absorption in the gastrointestinal tract

Area of Science:

• Environmental Science
• Microbiology
• Biotechnology

Background:

• Chronic exposure to arsenite in food and water poses a significant global health risk.
• Current strategies are insufficient to prevent ingested arsenite absorption via the gastrointestinal tract.

Purpose of the Study:

• To engineer a probiotic bacterium for in situ sensing and sequestration of dietary arsenite.
• To develop a practical, probiotic-based method for reducing host absorption of ingested arsenite.

Main Methods:

• Engineered Escherichia coli Nissle 1917 (EcN) with an arsenite-responsive genetic toggle switch.
• Incorporated a high-affinity, non-toxic arsenite-binding protein as a chelator within the engineered EcN.
• Utilized a mass-transfer model for in vivo dosing and conducted mouse studies to assess efficacy.

Main Results:

• Engineered EcN demonstrated efficient in vitro arsenite removal while maintaining robust growth.
• Mouse studies confirmed that engineered EcN reduced arsenite absorption into the bloodstream.
• The probiotic approach promoted fecal elimination of arsenite in vivo.

Conclusions:

• Engineered EcN provides a promising probiotic-based strategy for reducing dietary arsenite absorption.
• This approach offers a novel solution for mitigating the health impacts of toxic pollutants in food and water.
• Further development could lead to practical interventions for managing arsenic exposure.