Written by: Kari Raman, PharmD, RPh
Published May 2, 2023

Escherichia – A Double-edged Sword: Probiotic and Pathogen

Escherichia, commonly referred to as E. coli, is a diverse group of bacteria that can be found in the intestines of healthy humans and a lot of normal/healthy animals. While certain strains are known to be pathogenic and cause infections, others are recognized as probiotics with potential health benefits. In this article, we’ll explore the dual nature of Escherichia and discuss its use as a probiotic, as well as the importance of proper hygiene when dealing with this bacterium.

This is definitely a bacteria that causes some confusion among the patients at pharmacies I’ve worked in. That’s because the most well-known member of the Escherichia genus is Escherichia coli (E. coli). E. coli is a normal resident of the human gut and is normally believed to be beneficial for human health. However, some strains of E. coli can cause serious infections. You probably have heard of E. coli outbreaks that make people sick (here is an outbreak linked to not-well washed lettuce at a fast food chain.) It can also be a common cause of UTIs.

What does Escherichia/E. coli do?

Escherichia has a complex role in the human body. On one hand, some strains can be beneficial, producing essential vitamins like vitamin K and B-complex vitamins, while aiding in digestion and supporting a healthy gut microbiome. On the other hand, certain strains can be harmful, leading to severe gastrointestinal illnesses or even life-threatening infections, usually caused by poor hygiene or not-well prepared (often unwashed) food. It is crucial to understand that not all strains of E. coli are created equal, and their effects on the body can vary significantly. You don’t want to randomly start trying to get more of this probiotic bacteria without understanding what you are trying to accomplish, although I feel confident that most reputable probiotic suppliers are going to use safe strains of this probiotic species.

An interesting history for this probiotic

In 1917, a scientist named Alfred Nissle found a potentially powerful probiotic strain, now called E. coli Nissle 1917. It was World War I, and many soldiers were getting extremely sick from diarrhea and other stomach/gastrointestinal diseases. However, one soldier did not get sick. Nissle thought that the soldier might have a special type of E. coli in his gut that protected him from getting sick. He tested his theory by studying a sample of the soldier’s stool and found that this particular strain of E. coli could fight off harmful bacteria in the lab. This discovery led to further research on the potential health benefits of the EcN strain. 

I think it’s amazing to find probiotics like this – similar to how the probiotic yeast Saccharomyces was found, read about in my Saccharomyces article.

Is E. coli a probiotic?

There are some very specific strains of the E. coli bacteria species that have been used in probiotic supplements. The strain EcN discovered by Alfred Nissle, for example, is contained in the Mutaflor probiotic supplement. Patients need to be very careful when choosing a probiotic with this bacteria, as many strains are very dangerous, and they should talk with their doctor about the conditions they are seeking to treat before taking it. 

Which strain of E. coli is used in probiotics

Escherichia coli Nissel is a commonly used probiotic available from several, well-known providers. Most well-known strains of E. coli are often quite dangerous and can cause serious infections. It’s best to consult with a doctor before beginning a supplement program. 

Escherichia probiotics clinical trial summary

There are numerous studies conducted on Escherichia, particularly focusing on the probiotic strain E. coli Nissle 1917. This strain has demonstrated potential health benefits in various clinical trials, including:

Maintaining gut health: The right strains of E. coli have been shown to support a healthy balance of gut bacteria and contribute to overall digestive health. It can help prevent the colonization of pathogenic bacteria in the intestines by competing for resources and producing substances that inhibit the growth of harmful bacteria. For example, this cool study by researchers at UC Davis, shows that the right kind of Escherichia coli out competes Salmonella bacteria in the guts of mice. Salmonella is a type of bacteria that can cause food poisoning and other serious gastrointestinal problems. Once salmonella bacteria reach the gut, they can attach themselves to the lining of the small intestine, where they begin to grow and multiply. Salmonella releases toxins that can damage the cells lining the gut. This damage can lead to symptoms such as diarrhea, abdominal pain, and nausea. In some cases, the infection can become more severe. But it seems as if the right probiotic bacteria, like E. coli, can ‘box out’ the bad bacteria and help keep your gut healthier. That being said, even if you are taking a good probiotic you should never, ever eat anything with Salmonella (so proper food handling and preparation practices, like washing hands and surfaces thoroughly, cooking foods to the appropriate temperature, and avoiding cross-contamination of raw and cooked foods).

Boosting the immune system: Some studies suggest that certain strains of E. coli may help stimulate the immune system and enhance its ability to fight off infections. I would say this is more based on how particular blood and gut proteins respond to people in clinical trials, so it’s not as clear cut as other research. But still, it may be beneficial.

Treatment of inflammatory bowel disease (IBD): There are a few trials (this article summarizes them) that suggest that E. coli Nissle 1917 may help to reduce symptoms of ulcerative colitis and other forms of IBD. The exact cause of IBD is not fully understood, but it is believed to involve a combination of genetic, environmental, and immunological factors. The condition is often treated with medications that help to reduce inflammation and control symptoms. Probiotics, including E. coli Nissle 1917, have been studied for their potential to help manage symptoms of IBD. Some studies suggest that probiotics may help to reduce inflammation in the gut and improve the balance of beneficial bacteria in the microbiome.

Reducing the risk of allergies: A few studies have suggested that early exposure to certain strains of E. coli may reduce the risk of developing allergies later in life. This is a use case where you need to talk to your child’s pediatrician before beginning any supplementation. 

It’s important to note that much of the research on E. coli as a probiotic is still in its early stages, and more studies are needed to fully understand its potential benefits.

Escherichia coli – the right strain is a helpful probiotic 

In conclusion, the complex and dual nature of Escherichia (E. coli) bacteria presents both challenges and opportunities for researchers and healthcare providers. While some strains are known to be pathogenic, causing severe infections and public health crises, others have been identified as probiotics that may offer potential health benefits. The key lies in understanding and differentiating between these strains, allowing for the safe and effective use of probiotics while minimizing the risks associated with pathogenic strains.

The discovery of E. coli Nissle 1917, a strain with probiotic properties, has led to a growing body of research on its potential health benefits. Clinical trials have demonstrated that E. coli Nissle 1917 may support gut health by maintaining a healthy balance of bacteria in the gut microbiome and preventing the colonization of pathogenic bacteria. This probiotic strain has also been shown to stimulate the immune system, potentially enhancing the body’s ability to fight off infections.

Moreover, E. coli Nissle 1917 has shown promise in the treatment of inflammatory bowel disease (IBD), including ulcerative colitis. While the exact cause of IBD is not fully understood, it is believed to involve a combination of genetic, environmental, and immunological factors. Probiotics like E. coli Nissle 1917 may help manage IBD symptoms by reducing inflammation and improving the balance of beneficial bacteria in the gut microbiome.

It is important to emphasize that research on E. coli as a probiotic is still in its early stages, and more studies are needed to fully understand its potential benefits and risks. Healthcare providers and patients need to exercise caution when choosing a probiotic containing E. coli, as many strains are dangerous. Proper hygiene and food handling practices are also crucial to minimize the risk of infection with pathogenic strains.

As the understanding of the human microbiome continues to expand, so too does the potential for harnessing the power of beneficial bacteria like E. coli Nissle 1917. However, it is vital that researchers, healthcare providers, and consumers alike remain vigilant and informed about the potential risks associated with certain strains of E. coli. By doing so, we can work toward a future where probiotics play a more prominent role in supporting and maintaining overall health and well-being.

In summary, the double-edged nature of Escherichia bacteria underscores the importance of further research and cautious application of probiotics containing E. coli. As scientists continue to investigate the potential benefits of strains like E. coli Nissle 1917, it is crucial for healthcare providers and patients to carefully select and use probiotics, prioritizing safety and efficacy. By acknowledging both the risks and the potential benefits of Escherichia bacteria, we can move toward a better understanding of the human microbiome and its impact on health, paving the way for improved therapies and preventive measures in the future.

If you like this article, check out some of my other proboitic tips like How Long it Takes Probiotics to Work and Signs You Need Proboitics.

Pharmacist Kari Raman

I’m Kari Raman PharmD, RPh, and I am a licensed, practicing pharmacist. I hold a Doctorate in Pharmacy from The University of the Pacific, and I’ve served patients in retail, compounding and hospital pharmacies.

Probiotics are confusing!

One of the most common questions I get asked by patients is about probiotics. And the truth is, probiotics are not as well understood by the healthcare community as they should be.

So I’ve been reading a lot of probiotic clinical trials, and sharing what I’m learning here.

I hope Pharmacist Probiotics helps you find out if there is a type of probiotic that works for you!