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Probiotic: Escherichia coli Nissle 1917 (EcN, MutaFlor)

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Escherichia coli Nissle 1917 (EcN, MutaFlor)

What’s in this article:

  • What We Think
  • Availability and Cost
  • Background info & What you need to know
  • What the research says
  • New way of using the strain- (research funded by ccfa- added 4/5/23)
  • Pro’s & Con’s
  • Practitioner Resources


What We Think: Do we ever recommend this in our practice?

*Note- this is not intended to be individualized guidance. Speak to your health care providers to find out if it’s beneficial for you.

In our practice, we do not typically recommend this strain. Most of the positive research on this strain is for Ulcerative colitis and a few others listed in practitioner resources. However, there are some potential concerning side effects with this strain that were notable in our pros/con’s list.

Our consensus, is that there are many other strains we can recommend that are widely available, less costly and without the potential drawbacks.


Availability & Cost

  • Not available in the US, imported so higher cost
  • Available in Canada & Australia 
  • Brand name- Mutaflor

Background Info & What you need to know:

Escherichia coli Nissle (EcN) 1917 is a beneficial bacterial strain that has been used  for certain GI conditions including diarrhea and ulcerative colitis  EcN has been shown to have benefits in the intestinal tract.  

The product that contains EcN 1917 is called Mutaflor originally from Germany and has shown to be beneficial in patients with ulcerative colitis.  Mutaflor is registered in Australia and is used to also help with constipation and diarrhea.  Mutaflor, as mentioned previously, is used as a treatment plan for patients with ulcerative colitis during times of remission and when patients are unable to tolerate Mesalazine.  

Mutaflor is used in Australia, Germany, Canada, and other countries.  EcN 1917, has been recommended by the European Crohn’s and Colitis Organization and its view on this probiotic strain is one that has been backed up by research and has shown to be equally effective as mesalazine when taken twice per day.  

Interestingly, Korean guidelines have recommended the routine use of EcN 1917 for remission maintenance versus inducing remission in UC patients who have adverse events to 5-ASA medications.  EcN 1917 can also be administered in enema form which studies have shown to help induce remission in patients with UC.  While there is research on how EcN 1917 can be an effective therapy for UC, the use of 5-ASA treatment was still crucial to take during the study to prevent dropout rates due to symptoms. 

What the research says: See more in practitioner resources 

Oral Use in UC: There are some early findings that this strain could be helpful, but with some potential downsides too (see con’s list)

Study Details: In a double-blind, randomized, placebo-controlled study 118 UC patients on 5-ASA treatment who either received the EcN probiotic or placebo 1x/daily for 8 weeks. IBD questionnaire (IBDQ) scores and clinical remission and response rates were compared to each other. Fewer patients in the EcN group had lower IBDQ scores; Higher number of patients in the EcN group compared to placebo group had clinical response at 4 weeks. Endoscopic remission was reached at 8 weeks. 

Rectal Use in UC: There are some early findings that this strain could be helpful

Study Details: Explorative, randomized, double-blind, placebo-controlled, parallel-group, multicentre, phase II dose-finding study. This study looked at 90 patients between 18 and 70 years of age with UC proctitis/proctosigmoiditis (mild-moderate). Oral EcN was not allowed if taken within 4 weeks from starting the study or steroids and 5-ASA rectal treatment 2 weeks within starting treatment. Patients assigned to either the probiotic at a variety of doses (40 ml, 20 ml, 10 ml) or placebo. 6 patients received 10 ml, 7 received 20 ml, and 7 received 40 ml of EcN 1x/daily for 2 weeks. 40 ml of EcN topical therapy was shown to be the more effective. 

A Potential New Way to Use The Strain – (referring to recent CCFA post)

CCFA recently posted about a new way researchers are looking at using this probiotic strain. This strain has now been studied not just for it’s potential probiotic use – but also as a potential way to better deliver drugs in IBD.

Researchers have engineered a strain of E. coli (Nissel 1917) to secrete proteins of therapeutic value that could help make the delivery of drugs a bit better by creating a new drug delivery system that:

  • Does not systemically suppress a patient’s immune system
  • Delivers anti-inflammatory antibodies directly to where inflammation is present

This type of delivery method of modified E. coli has the power to improve outcomes for patients taking anti-TNF medication. This research is still being developed.

Pro’s & Con’s


  1. EcN has anti-inflammatory properties within the intestinal tract
  2. Antimicrobial benefits (anti-bacterial)
  3. EcN stops the production of Enterohemorrhagic Escherichia coli (EHEC) which can produce a toxin called Shiga 
  4. Competes with other pathogens
  5. Helps repair loosen junctions of the intestinal epithelial cells (known to cause “leaky gut”)
  6. Decreases proinflammatory properties including cytokines 
  7. EcN 200 mg/day is the same as having Mesalamine 1000 mg/d in maintaining UC remission


  1. E. Coli strain is genotoxic colibactin- causing damage to DNA cells and can promote colorectal cancer (3)
  2. EcN produces colibactin in both animal models and in human samples
  3. Evidence showing EcN to induce remission is scarce 
  4. Smaller studies, needing more evidence of EcN effectiveness in patients with UC
  5. Challenges with EcN 1917 research since it would be unethical to discontinue UC treatment in order to see how effective this probiotic strain is for UC alone.


Practitioner Resources

  • Collagenous Colitis: Decrease in stool frequency from 7.6 to 3.7/day (P=0.034) [Tromm et al, 2004]
  • Maintaining Remission, UC, Adults: Equally effective as mesalazine in preventing relapse (P=0.003) [Kruis et al, 2004]
  • Similar to Mesalamine: In adults with inactive ulcerative colitis, 12-week supplementation of E. coli Nissle 1917 (50 billion CFU/day; n=50) was shown to be an equally effective maintenance therapy option as mesalamine (500mg tds; n=53). Clinical activity index, relapse rates, relapse-free time, global assessment and histological findings at the end of the study revealed no significantly different results between groups. [Kruis et al, 1997]
  • Maintaining Remission, UC, Children/Teens: At 12 months, the relapse rate was 25% in probiotic-treated teens vs 30% in the mesalazine group [Henker et al, 2008]
  • Inducing Remission, UC, Adults: In conjunction with standard IBD therapy (corticosteroids), remission rate (P=0.05) and time to remission was equivalent to mesalazine(P=0.009); duration of remission was also equivalent (P=0.017) [Rembacken et al, 1999]
  • Inducing Remission, UC, Adults: In patients with active ulcerative colitis, application of probiotic enemas alongside standard medical treatment resulted in a dose-dependent remission rate in comparison to placebo (overall per-protocol responder rates P=0.0446). Time to remission was found to be dependent on dose of enema. [Matthes et al, 2010]
  • Inducing Remission, UC, Adults: Adults with ulcerative colitis who received E. coli Nissle 1917 alone (2.5-25 x 10^9 CFU per 100mg capsule, 100 mg × 1 for 4 days followed by 100 mg × 2 daily for 7 weeks; n=25) or as an add-on treatment after antibiotic therapy (Ciprofloxacin 500 mg × 2 daily for 1 week; n=25) did not have improved remission rates (as assessed by Colitis Activity Index scores) compared to those who received placebo alone (n=25) or antibiotics alone (n=25). [Petersen et al, 2014]
  • Diverticular disease: Addition to standard treatment resulted in significant lengthening of remission (2.4 vs 14.1 months; P<0.001) [Fric et al, 2003]
  • Constipation, adults: Increase in number of stools per week (4.9 vs 2.6; P<0.001) and a decrease in occurrence of hard stools (both P<0.05) [Mollenbrink et al, 1994]


Scaldaferri F, Gerardi V, Mangiola F, Lopetuso LR, Pizzoferrato M, Petito V, Papa A, Stojanovic J, Poscia A, Cammarota G, Gasbarrini A. Role and mechanisms of action of Escherichia coli Nissle 1917 in the maintenance of remission in ulcerative colitis patients: An update. World J Gastroenterol. 2016 Jun 28;22(24):5505-11. doi: 10.3748/wjg.v22.i24.5505. PMID: 27350728; PMCID: PMC4917610.

Matthes, H., Krummenerl, T., Giensch, M. et al. Clinical trial: probiotic treatment of acute distal ulcerative colitis with rectally administered Escherichia coli Nissle 1917 (EcN). BMC Complement Altern Med 10, 13 (2010).

Nougayrède JP, Chagneau CV, Motta JP, Bossuet-Greif N, Belloy M, Taieb F, Gratadoux JJ, Thomas M, Langella P, Oswald E. A Toxic Friend: Genotoxic and Mutagenic Activity of the Probiotic Strain Escherichia coli Nissle 1917. mSphere. 2021 Aug 25;6(4):e0062421. doi: 10.1128/mSphere.00624-21. Epub 2021 Aug 11. PMID: 34378987; PMCID: PMC8386472.

Park SK, Kang SB, Kim S, Kim TO, Cha JM, Im JP, Choi CH, Kim ES, Seo GS, Eun CS, Han DS, Park DI. Additive effect of probiotics (Mutaflor) on 5-aminosalicylic acid therapy in patients with ulcerative colitis. Korean J Intern Med. 2022 Sep;37(5):949-957. doi: 10.3904/kjim.2021.458. Epub 2022 Mar 31. PMID: 36068716; PMCID: PMC9449212.

Scaldaferri F, Gerardi V, Mangiola F, Lopetuso LR, Pizzoferrato M, Petito V, Papa A, Stojanovic J, Poscia A, Cammarota G, Gasbarrini A. Role and mechanisms of action of Escherichia coli Nissle 1917 in the maintenance of remission in ulcerative colitis patients: An update. World J Gastroenterol. 2016 Jun 28;22(24):5505-11. doi: 10.3748/wjg.v22.i24.5505. PMID: 27350728; PMCID: PMC4917610.