The non-pathogenic Escherichia coli strain Nissle 1917 – features of a versatile probiotic Original paper

What was studied?

This article reviews the versatile properties of Escherichia coli Nissle 1917 (EcN), focusing on its microbiological, immunological, and pharmacological characteristics as a probiotic. The strain’s origins, isolation, and non-pathogenic nature were explored, highlighting its lack of virulence factors, and its beneficial properties such as inhibiting pathogenic bacteria, enhancing epithelial barrier function, and modulating inflammatory responses. The article also delves into its safety profile, genetic makeup, and clinical efficacy in treating gastrointestinal diseases like chronic constipation, inflammatory bowel diseases (IBD), and diarrhea. The review examines EcN’s unique ability to promote intestinal health and its mechanisms of action, offering insights into its widespread use as a therapeutic agent.

Who was studied?

The study focuses on Escherichia coli Nissle 1917, a strain that was first isolated by Alfred Nissle in 1917 due to its antagonistic effects against pathogenic enterobacteria. EcN is a non-pathogenic strain of E. coli, meaning it does not carry any pathogenic virulence factors, such as enterotoxins, cytotoxins, or adhesins, making it safe for use in humans. It is commonly used in medical and veterinary applications as a probiotic agent. Its biological activities, safety, and therapeutic applications were analyzed, highlighting its use in treating chronic gastrointestinal conditions and its efficacy in both human and animal models. The study also notes its genetic features, such as genomic islands and the presence of fitness factors that contribute to its probiotic properties.

Most important findings

EcN is distinguished from other E. coli strains due to its ability to inhibit the growth of pathogenic bacteria, such as Salmonella, E. coli O157:H7, and Clostridium perfringens. It is particularly noted for its immunomodulatory properties, including its ability to reduce inflammation and improve intestinal barrier function. The strain produces microcins, which inhibit the growth of competing bacteria, and it has a unique lipopolysaccharide (LPS) structure that is crucial for its anti-inflammatory effects. EcN has been shown to stimulate the production of defensins and strengthen tight junctions in intestinal cells, helping to prevent conditions like leaky gut. Clinical trials have demonstrated EcN’s therapeutic potential in treating ulcerative colitis, chronic constipation, and infectious diarrhea.

Key implications

The findings suggest that E. coli Nissle 1917 is a highly effective probiotic with wide-ranging applications in gastrointestinal health. Its ability to inhibit pathogenic bacterial growth and modulate the immune system presents it as a potential therapeutic agent for chronic inflammatory diseases like ulcerative colitis and for improving gut health in general. EcN’s effects on the intestinal barrier and its ability to regulate inflammatory responses indicate its potential use in treating conditions associated with gut permeability and inflammation. Moreover, its safety profile and proven clinical efficacy make it a valuable alternative to traditional antibiotic treatments, especially for preventing and managing infections in both humans and animals.