Benefits and concerns of probiotics: an overview of the potential genotoxicity of the colibactin-producing Escherichia coli Nissle 1917 strain Original paper
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Divine Aleru
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Divine Aleru
Read MoreI am a biochemist with a deep curiosity for the human microbiome and how it shapes human health, and I enjoy making microbiome science more accessible through research and writing. With 2 years experience in microbiome research, I have curated microbiome studies, analyzed microbial signatures, and now focus on interventions as a Microbiome Signatures and Interventions Research Coordinator.
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Microbes
Microbes
Microbes, short for microorganisms, are tiny living organisms that are ubiquitous in the environment, including on and inside the human body. They play a crucial role in human health and disease, functioning within complex ecosystems in various parts of the body, such as the skin, mouth, gut, and respiratory tract. The human microbiome, which is […]
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Divine Aleru
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Researched by:
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Divine Aleru
ID
Divine Aleru
Read More
Microbiome Signatures identifies and validates condition-specific microbiome shifts and interventions to accelerate clinical translation. Our multidisciplinary team supports clinicians, researchers, and innovators in turning microbiome science into actionable medicine.
Divine Aleru
What was studied?
This review examines the benefits and potential risks associated with Escherichia coli Nissle 1917 (EcN), focusing on its use as a probiotic, particularly addressing concerns regarding its genotoxic potential due to the presence of the colibactin-producing pathogenic island (pks). EcN has been widely used to treat gastrointestinal disorders, but its potential to produce colibactin, a genotoxic metabolite, has raised safety concerns. The review provides an overview of in vitro and in vivo studies evaluating the probiotic and genotoxic properties of EcN, with a focus on its potential role in colorectal cancer (CRC) development.
Who was studied?
The review does not focus on specific individuals or groups. Instead, it synthesizes findings from a variety of studies that examine the effects of EcN in both human and animal models. These studies span from clinical trials to laboratory experiments investigating EcN’s genotoxicity, antimicrobial activity, immune-modulatory effects, and its role in maintaining gastrointestinal health. The review also considers data from metagenomic analyses, safety studies, and clinical trials evaluating EcN’s effectiveness in treating conditions like inflammatory bowel disease (IBD), ulcerative colitis (UC), and gastrointestinal infections.
Most important findings
The primary concern identified in the review is the potential genotoxicity of EcN, primarily due to the colibactin it produces. Colibactin has been shown to induce DNA double-strand breaks (DSBs) and mutations, which are implicated in the development of CRC. Several studies highlighted that colibactin-producing EcN could cause chromosomal abnormalities and promote neoplastic transformation in epithelial cells. However, EcN’s probiotic effects, such as modulating immune responses and enhancing gut barrier integrity, have been demonstrated to be beneficial. Despite the safety concerns, some in vitro studies and clinical trials have suggested that EcN does not exhibit harmful genotoxic effects in healthy individuals or under specific controlled conditions.
Key implications
While EcN has been shown to offer significant benefits, particularly in treating gastrointestinal disorders and modulating the immune system, its genotoxic potential due to colibactin production cannot be overlooked. This highlights the importance of evaluating the safety of probiotics, such as EcN, through comprehensive genetic and biochemical studies. Although EcN has been safely used for many years in specific therapeutic settings, its application should be carefully considered in vulnerable populations, such as immunocompromised individuals or those with a predisposition to cancer. Regulatory bodies and safety guidelines must address the risks associated with probiotic strains that produce potentially harmful metabolites, such as colibactin. Further research is essential to balance the therapeutic benefits of EcN with its possible risks, particularly in clinical settings.
E. coli Nissle 1917
Escherichia coli Nissle 1917 (EcN) is a rare, non-pathogenic strain of E. coli discovered during World War I from a soldier who did not get dysentery while others did. Unlike harmful E. coli, EcN acts as a probiotic: it settles in the gut, competes with bad bacteria for food and space, produces natural antimicrobials, and even helps strengthen the gut barrier.
Probiotics
Probiotics are live microorganisms that offer significant health benefits when administered in adequate amounts. They primarily work by modulating the gut microbiome, supporting a balanced microbial ecosystem. Probiotics have been shown to improve gut health, modulate immune responses, and even influence metabolic and mental health disorders. With growing evidence supporting their therapeutic potential, probiotics are increasingly recognized for their role in treating conditions like irritable bowel syndrome (IBS), antibiotic-associated diarrhea (AAD), and even mental health conditions like depression and anxiety through their impact on the gut-brain axis.