E. coli Nissle 1917
Escherichia coli Nissle 1917 (Mutaflor)
The one probiotic guideline-endorsed to keep ulcerative colitis in remission
Evidence tier
Strong
Research weight
Citations
11 verified / 11
Classification
Probiotics
❝
What the evidence says. Multiple high-quality RCTs / meta-analyses with consistent effects.
What is E. coli Nissle 1917?
E. coli Nissle 1917 (Escherichia coli Nissle 1917 (Mutaflor)) is a probiotic strain used for maintains remission in ulcerative colitis as effectively as standard mesalazine (guideline-endorsed alternative). NutriDex grades the human evidence as Strong. For maintaining remission in ulcerative colitis, E. coli Nissle 1917 (Mutaflor) is the best-evidenced indication: multiple double-blind, double-dummy RCTs and a meta-analysis show it is equivalent (non-inferior) to standard-dose oral mesalazine in preventing relapse, and it is the only probiotic ECCO guidelines endorse as a mesalazine alternative for UC maintenance. It does NOT reliably induce remission in active UC and has no proven role in Crohn's disease. Smaller controlled trials support faster resolution of acute and prolonged diarrhea in infants/toddlers, while IBS data are weak and mixed (benefit, if any, limited to diarrhea-predominant subtypes).
Purported Benefits
✓Maintains remission in ulcerative colitis as effectively as standard mesalazine (guideline-endorsed alternative)
✓Reduces relapse risk in UC patients intolerant of or seeking an alternative to 5-ASA therapy
✓Shortens duration of acute diarrhea in infants and toddlers (response ~2.3 days faster than placebo)
✓Reduces stool frequency and shortens prolonged (>4 day) diarrhea in young children
✓Effective for remission maintenance in pediatric/adolescent UC (open-label pilot data)
✓Possible benefit limited to diarrhea-predominant IBS subtype (weak, exploratory evidence)
Evidence by outcome
The same supplement can be well-proven for one use and unproven for another — here is the human evidence graded outcome by outcome.
| Outcome | Evidence | Effect | Studies |
|---|---|---|---|
| Maintenance of remission in ulcerative colitisMultiple RCTs plus meta-analysis show equivalence to mesalazine; guideline-endorsed alternative. | Strong | ↑ benefit · moderate | 3 |
| Inducing remission in active UCMeta-analysis found no superiority for inducing remission in active disease (wide CI). | Preliminary | — no effect | 1 |
| Acute/prolonged diarrhea duration (infants/toddlers)Two RCTs (Henker) shortened response by ~2.3 days and reduced stool frequency in young children. | Moderate | ↑ benefit · moderate | 2 |
| IBS symptomsOne RCT found no overall benefit; only diarrhea-predominant subtype showed a minor signal. | Preliminary | ↔ mixed · negligible | 1 |
Dosing & Compounds
Typical Dose
UC maintenance: typically two enteric-coated capsules (~5 x10^9 CFU, marketed as 200 mg EcN) once daily, after an initial titration over the first week; taken with food. Pediatric diarrhea trials used the oral suspension at 1-3 mL/day (~10^8 viable cells/mL) by age. Effective dose range studied is roughly 2.5-25 x10^9 viable EcN per day.
Active Compounds
Safety & Cautions
Generally well tolerated; the most common effects are transient bloating, flatulence, and abdominal discomfort (typically <5%, mainly during the first days). Because EcN is a live, colonizing E. coli, avoid in severely immunocompromised patients, those with central venous catheters, short-bowel/severe gut-barrier compromise, or acute pancreatitis due to rare risk of bacterial translocation/bacteremia. Translocation has been shown when both microbiota and adaptive immunity are defective. Pregnancy/lactation safety data are limited; use caution. Educational only — always check with your doctor or pharmacist before combining E. coli Nissle 1917 with any medicine.
Key Studies ★ 11 studies
Meta-analysis
Zhao 2025 (Nutr Metab)
✓ PubMed
Umbrella meta-analysis of 20 meta-analyses (46 datasets) found probiotics significantly reduced IBD relapse risk vs placebo (RR 0.55; 95% CI 0.22-0.88) but showed no significant difference vs mesalazine, consistent with E. coli Nissle 1917's role in maintaining UC remission.
Systematic review
Scaldaferri 2022
✓ PubMed
Systematic review/meta-analysis of E. coli Nissle 1917 for IBD reported a risk ratio of 1.08 (95% CI 0.86-1.37) for preventing relapse in inactive ulcerative colitis versus standard 5-ASA, indicating equivalence to mesalazine for maintenance.
Meta-analysis
Losurdo 2015
✓ PubMed
Systematic review/meta-analysis (6 trials, 719 pts): EcN equivalent to mesalazine for relapse prevention (recurrence 36.8% vs 36.1%; OR 1.07, 95% CI 0.70-1.64) but not superior for inducing remission in active UC (OR 0.92, 95% CI 0.15-9.66).
RCT
Faghihi 2015
✓ PubMed
DB placebo-controlled RCT in IBS (n=139, 6 wk): no significant difference in total symptom score overall; only diarrhea-predominant IBS showed a positive (sleep) response.
RCT
Kruis 2004
✓ PubMed
DB double-dummy RCT (n=327, 12 mo): relapse 40/110 (36.4%) with EcN 200 mg/day vs 38/112 (33.9%) with mesalazine; significant equivalence (p=0.003) for maintaining UC remission.
RCT
Rembacken 1999
✓ PubMed
DB randomized trial in UC: EcN was as effective as mesalazine for maintaining remission, establishing the non-pathogenic E. coli strain as a 5-ASA alternative.
RCT
Henker 2007
✓ PubMed
Confirmative DB RCT in infants/toddlers with acute diarrhea (n=113): median response 2.5 days with EcN vs 4.8 days placebo (2.3 days faster; p=0.0007).
RCT
Henker 2008
✓ PubMed
Placebo-controlled trial in infants/toddlers with prolonged diarrhea (>4 days): EcN reduced stool frequency and shortened diarrhea versus placebo.
Review
Chen 2026
✓ PubMed
Review of E. coli Nissle 1917 as a model chassis for engineered probiotics and the translational challenges involved.
Review
Brown 2026
✓ PubMed
Engineering commensal microbes for host health
Pilot study
Henker 2008 (pediatric UC)
✓ PubMed
Open-label pilot in pediatric/adolescent UC: relapse 6/24 (25%) with EcN vs 3/10 (30%) with 5-ASA, supporting maintenance use in young patients.