Tumor Colonization and Therapy by Escherichia coli Nissle 1917 Strain in Syngeneic Tumor-Bearing Mice Is Strongly Affected by the Gut Microbiome

"Tumor-selective treatment of metastatic pancreatic cancer with an engineered, probiotic living drug"

Pancreatic ductal adenocarcinoma (PDAC) poses significant challenges for effective treatment, with systemic chemotherapy often proving inadequate due to poor drug delivery and the tumor's immunosuppressive microenvironment. Engineered bacteria present a novel approach to target PDAC, leveraging their ability to colonize tumors and deliver therapeutic payloads. Here, we engineered probiotic Escherichia coli Nissle 1917 (EcN) to produce the pore-forming Theta toxin (Nis-Theta) and evaluated its efficacy in a preclinical model of PDAC. Probiotic administration resulted in selective colonization of tumor tissue, leading to improved overall survival compared to standard chemotherapy. Moreover, this strain exhibited cytotoxic effects on both primary and distant tumor lesions while sparing normal tissues. Importantly, treatment also modulated the tumor microenvironment by increasing anti-tumor immune cell populations and reducing immunosuppressive markers. These findings demonstrate the potential of engineered probiotic bacteria as a safe and effective therapeutic approach for PDAC, offering promise for improved patient outcomes.

Advanced probiotics: bioengineering and their therapeutic application

The role of gut bacteria in human health has long been acknowledged and dysbiosis of the gut microbiota has been correlated with a variety of disorders. Synthetic biology has rapidly grown over the past few years offering a variety of biological applications such as harnessing the relationship between bacteria and human health. Lactic acid bacteria (LAB) are thought to be appropriate chassis organisms for genetic modification with potential biomedical applications. A thorough understanding of the molecular mechanisms behind their beneficial qualities is essential to assist the multifunctional medicinal sectors. Effective genome editing will aid in the creation of next-generation designer probiotics with enhanced resilience and specialized capabilities, furthering our knowledge of the molecular mechanisms behind the physiological impacts of probiotics and their interactions with the host and microbiota. The goal of this review is to provide a brief overview of the methods used to create modified probiotics with the scientific rationale behind gene editing technology, the mechanism of action of engineered probiotics along with their application to treat conditions like inflammatory bowel disease, cancer, bacterial infections, and various metabolic diseases. In addition, application concerns and future directions are also presented.

Engineering bacteria for cancer immunotherapy

Bacterial therapeutics have emerged as promising delivery systems to target tumors. These engineered live therapeutics can be harnessed to modulate the tumor microenvironment or to deliver and selectively release therapeutic payloads to tumors. A major challenge is to deliver bacteria systemically without causing widespread inflammation, which is critical for the many tumors that are not accessible to direct intratumoral injection. We describe potential strategies to address this challenge, along with approaches for specific payload delivery and biocontainment to ensure safety. These strategies will pave the way for the development of cost-effective, widely applicable next-generation cancer therapeutics.

Bacterial Therapy of Cancer: A Way to the Dustbin of History or to the Medicine of the Future?

Bacteria are the constant companions of the human body throughout its life and even after its death. The history of a human disease such as cancer and the history of microorganisms, particularly bacteria, are believed to closely intertwined. This review was conceived to highlight the attempts of scientists from ancient times to the present day to discover the relationship between bacteria and the emergence or development of tumors in the human body. Challenges and achievements of 21st century science in forcing bacteria to serve for cancer treatment are considered. The future possibilities of bacterial cancer therapy, including the creation of bacterial microrobots, or "bacteriobots", are also discussed.