What This Strain Does
Enterococcus faecium is a hardy, gram-positive bacterium naturally found in the human gastrointestinal tract and fermented foods. As part of the normal intestinal flora, it plays a role in maintaining gut balance and preventing colonization by pathogenic organisms. While the genus Enterococcus includes some hospital-associated pathogens, specific probiotic strains of E. faecium have been carefully selected and characterized for their safety and health benefits, earning regulatory approval in multiple countries.
The probiotic potential of E. faecium stems from several mechanisms. This bacterium produces lactic acid and bacteriocins—natural antimicrobial compounds—that inhibit the growth of harmful bacteria including Salmonella, E. coli, and Clostridium species. E. faecium is remarkably resilient, surviving stomach acid, bile salts, and varying temperatures better than many other probiotic species. This hardiness ensures that viable bacteria reach the intestines where they can provide benefits.
E. faecium also demonstrates impressive colonization ability, adhering well to intestinal epithelial cells and establishing itself among the resident gut flora. This colonization supports competitive exclusion—the process by which beneficial bacteria occupy ecological niches and consume resources that might otherwise support pathogen growth. By establishing and maintaining its presence, E. faecium helps preserve the balance of the gut ecosystem.
Importantly, probiotic strains of E. faecium undergo rigorous screening to ensure they do not carry antibiotic resistance genes that could be transferred to other bacteria. The strains used in commercial probiotics are specifically selected for their safety profile and beneficial properties, distinguishing them clearly from environmental or hospital-associated strains of the same species.
Research Highlights
Clinical research supports the use of characterized E. faecium strains for specific health applications:
Acute Diarrhea Treatment: A meta-analysis published in the World Journal of Gastroenterology examined multiple clinical trials of E. faecium SF68 in acute diarrhea. The analysis found that the probiotic significantly reduced diarrhea duration compared to placebo, with effects comparable to other established probiotic interventions. Benefits were observed in both adults and children.
Antibiotic-Associated Diarrhea Prevention: Research published in the Journal of Clinical Gastroenterology demonstrated that E. faecium supplementation during antibiotic therapy reduced the incidence of diarrhea and improved stool consistency. The protective effect was particularly notable in patients taking broad-spectrum antibiotics known to disrupt gut flora.
Traveler’s Diarrhea Prevention: Clinical trials have examined E. faecium for preventing traveler’s diarrhea. A study of European travelers to tropical destinations found that those taking E. faecium SF68 experienced significantly lower rates of diarrhea compared to placebo, with the greatest protection observed during the first two weeks of travel.
IBS Symptom Relief: A randomized controlled trial published in the European Journal of Gastroenterology and Hepatology found that E. faecium, in combination with other probiotics, reduced abdominal pain and bloating in IBS patients. Symptom improvements were accompanied by positive changes in gut microbiota composition.
Specific Strains to Look For
Strain identification is particularly important for E. faecium, as only specific characterized strains have demonstrated safety and efficacy:
E. faecium SF68 (also designated E. faecium NCIMB 10415 or E. faecium Fargo 688) is the most extensively studied probiotic strain, with decades of clinical research and a strong safety record. It has been used in commercial probiotic products in Europe for over 30 years.
E. faecium M-74 has been researched for its cholesterol-lowering properties and appears in some cardiovascular health-focused probiotic formulations.
E. faecium T110 has been studied primarily in veterinary applications but has research supporting its general probiotic properties.
When selecting products, absolutely ensure the specific strain is identified. Generic E. faecium labeling without strain designation should be avoided, as strain identification provides assurance of the safety characterization that distinguishes probiotic strains from other members of this species.
What to Look For in Products
Given the importance of strain-specific safety data for E. faecium, product selection requires careful attention:
Strain Identification Required: Only purchase products that clearly identify the specific E. faecium strain used (such as SF68). This is more important for E. faecium than for many other probiotic species due to the potential for confusion with non-probiotic strains.
CFU Count: Clinical studies have typically used 75-200 million CFU per dose. While lower than some other probiotics, these doses have proven effective in trials. Some products provide higher counts for specific applications.
Quality Assurance: Choose products from established manufacturers with clear quality control processes, third-party testing, and regulatory compliance documentation.
Combination Products: E. faecium often appears in multi-strain formulas alongside Lactobacillus and Bifidobacterium species. These combinations may provide broader benefits while including the specific anti-diarrheal properties of E. faecium.
Storage Requirements: While E. faecium is relatively hardy, follow product-specific storage instructions. Some formulations benefit from refrigeration to maintain optimal potency.
Regulatory Status: E. faecium SF68 has Qualified Presumption of Safety (QPS) status in Europe. In the United States, it appears in supplements under the regulatory framework for dietary supplements.
Potential Side Effects
Characterized probiotic strains of E. faecium have demonstrated good safety in clinical trials. However, some considerations apply:
Initial digestive symptoms: Gas, bloating, or mild digestive discomfort may occur during the first few days of use. These symptoms typically resolve as the gut adjusts.
Not for immunocompromised individuals: As with other probiotics, E. faecium should be used with caution—and under medical supervision—in severely immunocompromised individuals, those with central venous catheters, or critically ill patients.
Strain specificity matters: The safety data applies specifically to characterized probiotic strains like SF68. This is not a genus-wide recommendation, and only products with identified probiotic strains should be used.
Monitor for adverse reactions: While rare, discontinue use and consult a healthcare provider if unusual symptoms occur.
In healthy individuals, including children and elderly adults, characterized E. faecium probiotic strains have demonstrated excellent tolerability when used at recommended doses.
How to Take
For Acute Diarrhea: Take 75-200 million CFU twice daily at the onset of symptoms. Continue until symptoms resolve, typically 3-7 days. Maintain adequate hydration and seek medical attention if symptoms are severe or persistent.
For Antibiotic-Associated Diarrhea Prevention: Begin taking E. faecium when starting antibiotic treatment. Take doses 2-3 hours apart from antibiotics if possible. Continue throughout the antibiotic course and for 1-2 weeks afterward.
For Traveler’s Diarrhea Prevention: Start supplementation 5-7 days before travel. Take 75-200 million CFU daily throughout the trip. Continue for several days after returning home.
For IBS Support: Take according to product directions as part of a comprehensive probiotic regimen. E. faecium is often most beneficial as part of a multi-strain formula for IBS.
General Timing: E. faecium can be taken with or without food. The hardy nature of this bacterium means it survives gastric transit well regardless of stomach contents.
Duration of Use: For acute conditions, use until symptoms resolve. For ongoing gut health support, E. faecium can be used as part of a regular probiotic regimen, though rotating with other strains or multi-strain products may provide broader benefits.
Key Takeaways
- Hardy intestinal bacterium naturally found in the human gut and fermented foods, selected for probiotic use based on specific beneficial properties
- Strain identification is critical—only characterized strains like SF68 have the safety documentation distinguishing them from non-probiotic strains
- Clinically proven for reducing duration of acute diarrhea and preventing antibiotic-associated and traveler’s diarrhea
- Produces bacteriocins that inhibit pathogenic bacteria including Salmonella, E. coli, and Clostridium species
- Excellent survivability through stomach acid and bile, ensuring viable bacteria reach the intestines
- Good colonization ability helps maintain gut balance through competitive exclusion of pathogens
- Effective at lower doses than some probiotics—clinical benefits demonstrated at 75-200 million CFU
- Use with caution in immunocompromised individuals—consult healthcare providers for these populations
- Often combined with other probiotic species in multi-strain formulas for comprehensive gut support