The E-coli strain 'Nissle 1917' (Mutaflor) A Powerful Probiotic

The E-coli strain ‘Nissle 1917’ (Mutaflor) A Powerful Probiotic

When it comes to E. coli, not all E. coli strains are created equal and one, in particular, is actually a powerful probiotic. The E. coli strain Nissle 1917 can help to promote a healthy gut.

As a naturopath, I’ve treated many people with digestive issues and understand how miserable these problems can be.

In this article, I will explain what the E. coli strain is and how it could benefit you.

The Discovery of E. coli strain Nissle 1917 (Mutaflor)

This story began in the early part of the last century. The E. coli strain Nissle 1917 was first discovered back in 1917 during World War I. In Dobrudja, a region in the Balkans, armies from Russia and Romania were fighting the Central Powers.

The area was a battlefield and heavily contaminated with enteric pathogens, microbes that affect the intestine and make people sick. Not an ideal situation when soldiers needed to be fighting fit.

The German army was hit hard by intestinal infections, so when physician and bacteriologist Alfred Nissle showed up, they welcomed him with open arms. At this point in time, there were no antibiotics available to treat patients.

Nissle examined sick and healthy patients, taking stool samples from both. With E. coli, some strains can provide beneficial effects while others can make a person very sick.

As Nissle continued to collect stool samples from soldiers, one man caught his attention. He was a non-commissioned officer who despite others around him falling sick, remained healthy.   

After examining the stool sample from this officer, he found that a particular strain of E.coli behaved in a similar way to a probiotic.

The E. coli strain Nissle 1917 was isolated and coined while Nissle continued to run experiments to test its effectiveness as a treatment. The professor went on to grow the strain in his lab before popping two capsules back to test it, luckily producing no side effects.

In the same year as the discovery, Nissle began to manufacture the strain under the trade name Mutaflor, meaning flora-changing.

The fascinating story of a powerful probiotic that started its life in the trenches of the Balkans during the First World War isn’t a tale you’re likely to hear again!

Thanks to Nissle, it’s probably one of the most intensively investigated bacterial strain’s today.  

The E-coli strain 'Nissle 1917' (Mutaflor) A Powerful Probiotic

Characteristics of the E. coli strain Nissle 1917/Mutaflor

Probiotics are non-pathogenic living microorganisms that can offer numerous health benefits when consumed. Non-pathogenic organisms don’t cause harm or disease to any other living thing.  

So, what makes E.coli strain Nissle 1917 different from other strains?

E.coli strain Nissle 1917, often abbreviated to EcN is a non-pathogenic member of the E. coli family.

EcN doesn’t produce any enterotoxins or cytotoxins. Enterotoxins are toxins that are produced by some microorganisms and can cause gastrointestinal symptoms. Besides this, EcN has special characteristics that differentiate it from other harmful strains of E. coli. These features are thought to be important for its probiotic activities.

One specific characteristic of EcN is a particular lipopolysaccharide (LPS) in its outer cell membrane.

LPS plays a massive role in the structural integrity of bacteria and protects the membrane from certain kinds of attacks. In this case, LPS is responsible for EcN’s ability to decrease the inflammatory response of the immune system without showing adverse effects.  

Another important characteristic is the link between EcN and the intestinal epithelial cells. This connection leads to a strengthening of the epithelial barrier and the repair of ‘leaky gut’ phenomena.

Epithelial cells are a type of cell that lines the surface of your body and can be found on your skin, urinary tract, blood vessels, and organs.

Strain-specific characteristics of E. coli Nissle 1917 also include:

  • The ability to colonise
  • Can inhibit the growth and the killing of pathogens
  • Prevent the colonisation of pathogens in the gut
  • Anti-inflammatory properties
  • Stimulate colonic mucosa

EcN is thought to aid a disturbed gut barrier by stimulating the production of epithelial defensin. Defensins play an important role in host defence and can kill bacteria in a number of ways. They can be produced by blood and tissue cells.  

In addition to this, it’s been found that products of EcN metabolism may be helpful in treating patients with chronic constipation. Studies have shown that EcN may be therapeutically effective in a variety of conditions such as ulcerative colitis, diarrhoea and chronic constipation.

The E. coli strain Nissle 1917 is characterised by a number of features that set it aside from the rest of its family members. As a potent probiotic, it can work to promote digestive health.

The E-coli strain 'Nissle 1917' (Mutaflor) A Powerful Probiotic

What does Mutaflor Do?

Mutaflor is a probiotic which contains the E. coli strain Nissle 1917. During its discovery, it was found that it had a number of beneficial effects on various gastrointestinal disorders.

Our gastrointestinal tract contains hundreds of species of bacteria with the majority being found in the large intestine. This is often referred to as our gut flora (or gut microbiome).

Your gut flora is responsible for many crucial roles such as:

  • Help the body digest certain foods
  • Help with the production of some vitamins
  • Support the immune system, performing a barrier effect
  • Balanced and healthy gut bacteria is key to proper digestive functioning
The E-coli strain 'Nissle 1917' (Mutaflor) A Powerful Probiotic

When we are born, our gastrointestinal tract is sterile and contains no bacteria. The colonisation of bacteria starts during the birthing process. E.coli is one of the initial colonisers in the gut, creating the right internal environment for the complex balance of bacteria to begin. This balance plays such a vital role in health.

As one of the first colonisers of the infant gut. E. coli plays a role in establishing and maintaining a healthy gut. It also provides a defence barrier against harmful, pathogenic bacteria.

A study conducted in 2013 investigated exactly how some beneficial types of E. coli protect against other pathogenic strains. The results showed that harmful strains of E. coli must compete with EcN to get the nutrients they need to colonise, take over and infect the host.

The E-coli strain 'Nissle 1917' (Mutaflor) A Powerful Probiotic

Benefits of Mutaflor Probiotic

Mutaflor is a strong probiotic and has commonly been used to treat chronic constipation. The E. coli strain could also be beneficial to a number of health conditions including irritable bowel syndrome and irritable bowel disease.

Irritable Bowel Disease

Irritable bowel disease (IBD) is a term generally used to cover two conditions: ulcerative colitis and Crohn’s disease. Both are long-term conditions that include the inflammation of the gut. Ulcerative colitis only impacts the colon whereas Crohn’s disease can affect any part of the digestive system.

Almost 75,000 Australians have Crohn’s disease or ulcerative disease, with the number only projected to increase. IBD is becoming more complex and more prevalent throughout the population. It’s estimated to affect 1 in 250 people aged 5-40.

In three randomised studies, Mutaflor was compared with mesalazine on the remission maintenance in patients with ulcerative colitis. Mesalazine is a medication that is commonly used to treat inflammatory bowel disease including ulcerative colitis.

The first study compared remission behaviour in patients being treated with either Mutaflor or mesalazine. The second study focused on treating an acute attack. The third and final study was carried out in ten European countries and again, compared the E. coli strain Nissle 1917 to standard medication.

All three studies concluded that there were no significant differences between the Mutaflor and the mesalazine group. When taken orally, two at a time daily, Mutaflor proved to be just as effective as mesalazine.     

In one study, 28 patients with Crohn’s disease were treated with prednisolone and Mutaflor versus placebo over the course of one year. Scientists found that once remission had been reached, the Mutaflor patient group experienced fewer relapses than the control group.

The E-coli strain 'Nissle 1917' (Mutaflor) A Powerful Probiotic

Leaky Gut

Leaky gut is also referred to as increased intestinal permeability. It’s a digestive condition in which bacteria and toxins “leak” through the intestinal wall. When the intestinal walls become loose, the gut becomes more permeable and can allow bacteria and toxins to leak into the bloodstream.

When the gut is “leaky”, it can cause inflammation throughout the body and may trigger a reaction from the immune system. Symptoms of a leaky gut can include bloating, digestive issues, tiredness and skin problems.

Factors that are believed to play a role in a leaky gut are:

  • Excessive alcohol intake
  • Very high sugar in the diet
  • Stress
  • Poor gut health
  • Yeast overgrowth
  • Nutritional deficiencies
  • Inflammation

One study found that the probiotic E. coli strain Nissle 1917 inhibited leaky gut by enhancing mucosal integrity. A thin layer of mucus covers the epithelial cells in your gut and this is essential for protecting these cells.

While the mucus doesn’t specifically act as an intestinal barrier, it protects our epithelial cells from inflammatory-causing bacteria and compounds. It’s vital for epithelial cell functioning which is crucial in preventing leaky gut.   

If you are interested in learning more about leaky gut, check out our article “Do you have a leaky gut? (Plus warning signs to look for)”

The E-coli strain 'Nissle 1917' (Mutaflor) A Powerful Probiotic

Irritable Bowel Syndrome

If you’re one of the many people that experience irritable bowel syndrome (IBS) you’re not alone. It’s estimated that IBS affects 10-15% of the population globally.

IBS is one of the most common gastrointestinal disorders and tends to be under-diagnosed as people with symptoms of IBS may not seek proper medical attention. Symptoms of IBS include:

  • Abdominal pain and cramping
  • Constipation
  • Diarrhoea
  • Gas and bloating
  • Fatigue  
  • Food intolerance
  • Anxiety

The Guideline of the German Society of Digestive and Metabolic Diseases recommends probiotics such as E. coli Nissle 1917 as a treatment option for irritable bowel syndrome.

In a multicentre study, 41 patients with IBS were treated with Mutaflor over four weeks. After four weeks, the majority of patients saw improvements in their IBS symptoms especially excessive bloating. Scientists found that 78% of patients rated the tolerance of Mutaflor as “good” to “very good”.   

The E-coli strain 'Nissle 1917' (Mutaflor) A Powerful Probiotic

Chronic Constipation

Chronic constipation is one of the most common digestive complaints I hear. It doesn’t just make you feel bloated but headachy, uncomfortable and irritable.

Chronic constipation can vary among different people. For some, it may mean infrequent bowel movements for weeks at a time and to others, it may mean straining or having difficulty passing stools. Either way, it’s very unpleasant.  

Mutaflor has long been used as a treatment for chronic constipation. In one eight-week study, patients who were treated with Mutaflor reported a significant increase in weekly stool frequency compared to the placebo group.

In a randomised trial carried out over nine weeks, researchers investigated the efficacy of Mutaflor. They found that the E. coli strain Nissle 1917 proved to be successful in treating chronic constipation and was almost entirely free of side effects.

The E-coli strain 'Nissle 1917' (Mutaflor) A Powerful Probiotic


Diarrhoea is classed as loose, watery stools, passed more frequently than normal. Acute diarrhoea can last for a few days but chronic diarrhoea can last for weeks. Some of the most common causes of diarrhoea include:

  • Viruses
  • Bacteria from contaminated water or food
  • Food sensitivities and intolerances
  • Problems with the colon function, like irritable bowel syndrome
  • Diseases that affect the stomach, such as Crohn’s disease

In one study looking at acute diarrhoea in children and infants, researchers found that E.coli strain Nissle 1917 was a safe and well-tolerated treatment. It showed significant superiority over the placebo group and reduced the duration of acute diarrhoea by 2.3 days.

Another study looked into using the probiotic E. coli strain Nissle 1917 for treating diarrhoea of more than four days duration in infants and toddlers. Scientists concluded that Mutaflor reduced the duration of the diarrhoea and was a suitable remedy for young children.

The E-coli strain 'Nissle 1917' (Mutaflor) A Powerful Probiotic

E. coli Nissle 1917 and Increased Serotonin

The relationship between the gut and the brain is a complex one, known as the gut-brain axis. An unhappy intestine can send signals to the brain just as a troubled brain can send signals to the gut.

Probiotics have the ability to restore the balance of bacteria in the gut and therefore may have a potential role in treating and preventing conditions such as anxiety and depression.

A growing body of evidence suggests that gut microbes can interact and affect serotonin signalling. Serotonin is a chemical in the brain that sometimes referred to as the happy chemical as it contributes to happiness. It’s thought to play a key role in appetite, mood, sleep, memory and digestion. Low levels of serotonin have been linked to depression.

The amount of sleep you get each day can impact your day massively. It’s no secret that we’re connected more than ever and switching off after a long day can be difficult.

In a report titled the Re-awakening Australia – The Economic Cost of Sleep Disorders in Australia, it’s estimated that more than 1.5 million Australian adults suffer from some kind of sleep disorder.

Tryptophan is an amino acid that helps the body to produce more serotonin, it comes from foods like spinach, turkey, salmon and eggs. You can find a large amount of this amino acid stored in the gastrointestinal tract (GI).

Research has shown that the E. coli strain Nissle 1917 is needed to convert tryptophan to serotonin, and this friendly bacteria also increases serotonin levels in the GI tract as well as the rest of the body.

The E-coli strain 'Nissle 1917' (Mutaflor) A Powerful Probiotic

Serotonin also helps to regulate stress by letting the brain know when to ask for less or more activity from the adrenal glands. Your adrenal glands help your body respond to stress by releasing hormones like adrenaline and cortisol. When there is a healthy balance of gut bacteria, the signals sent to your brain in response to stress are less extreme, therefore less damaging to the body.  

The E-coli strain 'Nissle 1917' (Mutaflor) A Powerful Probiotic


A strain of E. coli isn’t the first thing that pops into your head when you think of a probiotic or treatment for constipation. The role our gut bacteria plays in our overall health is regularly underestimated.

By establishing and maintaining a healthy gut, you’re better protected against harmful bacteria. Isolated over 100 years ago, EcN could play a major part in gut health and encouraging a proper functioning digestive system.

This is one of the many bacteria I look at with gut microbiome testing. I have seen incredible results with some clients when using Mutaflor in a targeted way.

Go here to learn more about gut microbiome testing.

I hope you enjoyed reading this article. Please share your thoughts in the comments 🙂

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