Benefits
Studied in 1,143 people with acute infectious diarrhea
Treatment RCT in 1,143 patients with acute infectious diarrhea: SF68 three times daily for 7 days reduced median time to resolution of diarrhea from 4 days to 3 days. Other symptoms also cleared faster. The trial was large and placebo controlled, but it was run by the maker of the product, it had not been published before a 2020 write-up, and it has not been independently replicated. The benefit was about one day of faster recovery (median 3 days versus 4) in people who were already ill.
Studied in 1,397 people taking antibiotics
AAD prevention RCT in 1,397 patients on antibiotics: SF68 twice daily for 7 days reduced antibiotic-associated diarrhea from 16.2% on placebo to 8.6%, a 7.6 percentage point absolute difference (about 47% in relative terms). The trial came from the manufacturer's own study programme and has not been independently replicated.
A Cochrane review of 4 small trials (333 people), rated low quality
A Cochrane review of probiotics for acute infectious diarrhea included 4 small SF68 trials with 333 people in total, which together suggested a lower risk of diarrhea lasting 4 days or more. This review is not one of the references cited on this page, so nothing here can be checked against a linked source, and 333 people spread across 4 trials is a small evidence base. Honest limitation acknowledged in the Cochrane review itself: trial quality assessed as insufficient, with unclear or inadequate allocation concealment, no blinding in some trials, and no/unclear intention-to-treat analyses.
Registered as a medicine in parts of Europe, not a proven supplement benefit
In Austria, Italy and Switzerland, Bioflorin is registered as a medicine for acute infectious gut inflammation, travelers' diarrhea and antibiotic-associated diarrhea. That is a regulatory status in those countries, not evidence that a dietary supplement version does the same thing, and it does not apply in the United States. Cernivet is the veterinary version of the same strain, sold for animals. Joins Bacillus clausii (Enterogermina), E. coli Nissle 1917 (Mutaflor), and Clostridium butyricum MIYAIRI 588 (MIYA-BM) in the rare category of probiotics with pharmaceutical licensure rather than dietary-supplement-only status.
Laboratory mechanism work, not a human study
Laboratory work reported that an enzyme from SF68 called arginine deiminase quiets two inflammation signaling pathways in cells. This is cell-level work, not a study in people, and the paper is not among the references cited on this page. It is a possible explanation for the diarrhea findings, not evidence of an anti-inflammatory or immune benefit in humans.
Favorable adverse event profile
AE incidence 1.1-1.4% in RCTs, 4.7-7.4% in open-label studies. Stopping because of intolerance was slightly more common on placebo than on SF68 (0.7% versus 0.1%), but that difference was not statistically significant, so it should not be read as the probiotic being better tolerated than a dummy capsule. All of these safety numbers come from the manufacturer's own study programme.
Safety: Enterococcus faecium is an opportunistic pathogen
Enterococcus faecium can cause infections in vulnerable people and is a well-known carrier of vancomycin resistance genes, which is why regulators require probiotic strains of this species to be screened for transferable resistance genes. SF68's record in licensed European use is reassuring, but it does not remove the species-level concern. Anyone who is immunocompromised, has a heart valve problem or a central line, or is in hospital should not take this on their own. Some animal infection studies report no benefit or adverse effects (higher bacterial loads, Salmonella Typhimurium shedding) in animal models. Those animal findings are unresolved rather than reassuring, and they should not be dismissed as relevant only to veterinary use.
Mechanism of action
Arginine deiminase NF-κB and JNK(AP-1) inhibition
SF68 arginine deiminase enzyme inhibits host cell NF-κB and JNK(AP-1) pathway activation, a proposed explanation for possible anti-inflammatory effects. This comes from laboratory work in cells, not from a study in people, and the paper is not among the references cited on this page.
Time-to-resolution acceleration
In people with acute infectious diarrhea, the manufacturer's trial reported a median resolution time of 3 days on SF68 versus 4 days on placebo, a difference of about one day. Why this happens is not established. Suggested explanations include less gut inflammation, crowding out of pathogens, and support for the gut lining, none of which was measured in the trial.
AAD prevention via competitive exclusion
In the prevention trial, antibiotic-associated diarrhea occurred in 8.6% of people on SF68 versus 16.2% on placebo, a 7.6 percentage point absolute difference (about 47% in relative terms). The suggested explanation is that the strain occupies space in the gut while antibiotics disrupt the normal bacteria, but the trial did not measure this, and it did not report Clostridioides difficile infection as an outcome.
Acid and bile resistance
SF68 is reported to survive stomach acid and bile, so it does not need a special enteric coating to reach the gut. This is a manufacturing characteristic rather than a proven health benefit, and it is not documented in the reference cited on this page.
Intestinal inflammation mitigation
In laboratory cell experiments, the arginine deiminase pathway damped two inflammation signals. Whether this actually reduces inflammation in the human gut has not been shown, and it has not been linked to the shorter diarrhea seen in the trials. Treat it as a hypothesis rather than the established reason the product works.
Enterococcus species safety considerations
Enterococci can carry vancomycin resistance genes. These genes can in principle transfer to other bacteria, which is why regulators require probiotic strains of this species to be screened for them. The safety record here applies to the SF68 strain in the licensed Bioflorin product only, not to Enterococcus faecium in general, and not to other products containing this species. People who are immunocompromised, have a heart valve condition or a central line, or are in hospital should not take it without medical advice.
Clinical trials
Greuter T et al. 2020, Front Med, PMID 32656217. The single reference cited on this page. It reports four studies run by the manufacturer of SF68 (Bioflorin, Cerbios-Pharma) in people with acute infectious diarrhea and in people taking antibiotics: two randomized placebo-controlled trials and two open-label studies with no control group.
Clinical population described in trial publication.
Greuter T et al. 2020 (Front Med 7:276, doi:10.3389/fmed.2020.00276). Reports four studies run by the manufacturer. Treatment trial (n=1,143 people with acute infectious diarrhea): three times daily for 7 days, median time to resolution 3 days versus 4 days on placebo (P<0.001). Prevention trial (n=1,397 people taking antibiotics): twice daily for 7 days, antibiotic-associated diarrhea in 8.6% on SF68 versus 16.2% on placebo (P<0.001), a 7.6 percentage point absolute difference, about 47% in relative terms. Two open-label studies with no control group (n=5,093 treatment and n=4,340 prevention) were reported alongside these; without a control group they cannot separate the product from natural recovery. Limitations: all four studies come from the manufacturer's own programme (SF68 is Bioflorin, made by Cerbios-Pharma), none had been published before this 2020 write-up, the treatment period was only 7 days, and every clinical claim on this page rests on this one publication.
Cochrane Review included 4 SF68 clinical trials (n=333) demonstrating reduced risk for diarrhea ≥4 days.
Clinical population described in trial publication.
A Cochrane review included 4 small SF68 trials with 333 people in total, which suggested a lower risk of diarrhea lasting 4 days or more. This review is not among the references cited on this page, so it cannot be checked here. Limitation stated by the reviewers themselves: trial quality was judged insufficient with unclear/inadequate allocation concealment, no blinding in some, and no/unclear ITT analyses. Methodological caveats are part of the honest evidence picture for this strain.
Gut (doi:10.1080/19490976.2022.2106105) — SF68 arginine deiminase inhibits host cell NF-κB and JNK(AP-1) pathway activation.
Clinical population described in trial publication.
A laboratory paper (Gut Microbes, doi:10.1080/19490976.2022.2106105) reported that the SF68 enzyme arginine deiminase damps two inflammation signaling pathways in cells. No people were treated, so this is not a clinical trial, and the paper is not among the references listed on this page, so it cannot be checked here. It suggests a possible mechanism, not a demonstrated anti-inflammatory or immune benefit.