Additionally, a dose-response was observed, with higher doses of probiotics associated with the greatest protective effect, according to findings published in The American Journal of Gastroenterology, and presented at the International Probiotics Association's World Congress in Miami.
Significant reductions in the incidence of AAD were also recorded by the researchers, with only 15.5 and 28 per cent of the higher and lower dose probiotics group experiencing AAD, compared with 44 per cent of the placebo group.
Between five and 25 per cent of patients experience diarrhoea, including Clostridium difficile associated diarrhoea, as a complication of treatment with antibiotics. Over a quarter of a million C. difficile infections are reported in the US every year, which is more than the ‘flu (about 200,000). Between 15,000 and 30,000 deaths are believed to be due to C. difficile every year.
Current treatments, ranging from changing the antibiotics used to dietary changes, are reported to have limit effectiveness and people are subject to relapse.
The new study was described by the researchers as the “highest quality trial”. It was performed by Sprim Advanced Life Sciences, a CRO, and funded by Quebec-based Bio-K + International, the company behind the proprietary blend of probiotics.
“This study included patients who were prescribed with [the so-called high-risk antibiotics] cephalosporin, penicillin, and clindamycin,” wrote the researchers, led by Larry Miller. “Therefore, this study shows the efficacy of the Lactobacilli formula in the prevention of C.difficile-associated diarrhoea even when the most offending antibiotics are used.”
This is by no means the first trial to report a protective effect of probiotics against C. difficile. A Danone-supported study reported in 2007 that hospital-bound elderly patients receiving antibiotics experienced 22 per cent fewer cases of diarrhoea when taking daily probiotic drinks (Actimel).
The study, led by Mary Hickson from Imperial College, London, and reported in the British Medical Journal, did not include patients taking these co-called high-risk antibiotics. The Danone product contained Lactobacillus casei DN-114 001 (100 million colony forming units/ml), S. thermophilus (100 million cfu/ml), and L. bulgaricus (10 million cfu/ml).
The new study capsules of the probiotic blend of Lactobacillus acidophilus CL1285 and Lactobacillus casei LBC80R. Each capsule contained 50 billion cfu.
Dr Miller and his co-workers recruited 225 hospitalised people receiving antibiotic treatment. The participants were randomly assigned to one of three groups: Placebo (2 placebo capsules); low dose probiotic (one probiotic capsule plus one placebo); or the high dose probiotic (2 probiotic capsules). Supplements were started within 36 hours of the start of their antibiotic course, and continued for five days after the course finished.
Results showed that both probiotic groups experienced significant reductions in both AAD and C. difficile-associated diarrhea, compared with placebo. Furthermore, a dose effect was observed, with the higher dose probiotic group experiencing greater reductions. About10 per cent of the low-dose probiotic group experienced C. difficile-associated diarrhea, while only 1.2 per cent of the higher dose probiotic group experienced this, compared with 24 per cent in the placebo group.
In patients who did develop AAD, the duration of the symptoms was also reduced in the probiotic groups, compared to placebo, said the researchers.
The researchers note that the effects cannot be generalized to all probiotics and are specific to this particular blend.
“The proprietary probiotic blend used in this study was well tolerated and effective for reducing risk of AAD and, in particular, C. difficile-associated diarrhoea in hospitalized patients on antibiotics,” concluded Miller and his co-workers.
Source: The American Journal of Gastroenterology
Published online ahead of print, doi:10.1038/ajg.2010.11
“Dose–Response Efficacy of a Proprietary Probiotic Formula of Lactobacillus acidophilus CL1285 and Lactobacillus casei LBC80R for Antibiotic-Associated Diarrhea and Clostridium difficile-Associated Diarrhea Prophylaxis in Adult Patients”
Authors: X.W. Gao, M. Mubasher, C.Y. Fang, C. Reifer, L.E. Miller