Biomedical Breakthrough Uses Engineered Probiotic Bacteria to Deliver Targeted Anticancer Drugs Directly into Tumors

Shandong University researchers engineer E. coli to deliver anticancer drugs directly to tumors, establishing a new foundation for bacteria-assisted therapy.

By: AXL Media

Published: Mar 18, 2026, 9:03 AM EDT

Source: Information for this report was sourced from PLOS

Harnessing Probiotic Strains as Living Drug Delivery Vehicles

A pioneering study published in PLOS Biology has introduced a novel method for cancer treatment using genetically modified bacteria to deliver small molecule anticancer agents. Researchers at Shandong University in Qingdao, China, focused on Escherichia coli Nissle 1917 (EcN), a well known probiotic strain, as a base for their therapeutic framework. Unlike traditional treatments that circulate through the entire body, these engineered bacteria are designed to inhabit and interact specifically with the tumor microenvironment. By leveraging the natural ability of certain bacteria to colonize tumors, the research team has established a foundation for a bacteria assisted delivery system that could revolutionize how potent oncology drugs are administered to patients.

The Biosynthesis of Romidepsin within the Tumor Microenvironment

The core of the experiment involved the genetic engineering of the EcN strain to produce Romidepsin, also known as FK228, which is an FDA approved drug recognized for its powerful anti tumor properties. Using advanced genomic techniques, the scientists transformed the probiotic into a living factory capable of synthesizing the drug on site. When tested in a mouse model using breast cancer cells, the engineered EcN successfully localized within the tumor tissue and began releasing the therapeutic agent. This localized release ensures that the highest concentration of the drug is present exactly where it is needed, which may mitigate the severe side effects often associated with systemic drug delivery in human oncology.

Dual Action Therapy Combining Colonization and Chemical Efficacy

The research findings suggest that the efficacy of this treatment stems from a synergistic effect between the bacteria and the drug itself. The authors of the study noted that the tumor colonization properties of EcN work in tandem with the anticancer activity of Romidepsin to form a dual action therapy. In both laboratory settings and live mouse models, the bacteria remained stable and effective under varying physiological conditions. This suggests that the engineered strain is robust enough to survive the complex environment of a cancerous tumor while maintaining its primary function of drug secretion, effectively acting as a persistent, targeted therapy from within the malignancy.