Probiotics & Clostridium difficile

Joanna Scott-Lutyens BA (Hons) DipION

What is Clostridium difficile?

Clostridium difficile (C. difficile or C. diff) is a species of bacteria that is present naturally in the gut of around 60% of children under the age of 1 years old and 3% of adults.1,2 C. difficile does not cause any problems in healthy people with a well balanced gut microbiota (see Probiotics Learning Lab for glossary). However, antibiotics that are used to treat other health conditions can cause dysbiosis, a condition where the normal gut microbiota is disrupted; compromising a vital part of our immune system and allowing C. difficile to multiply.

Pathogenic strains of C. difficile produce two large protein exotoxins; known simply as toxin A and toxin B.3 These toxins can induce intestinal inflammation, fluid secretion and mucosal injury.4,5 This can result in conditions such as C. difficile-associated diarrhoea (CDAD) and, in more serious cases, colonic damage and pseudomembranous colitis.6

Who is at risk?

C. difficile cases occur most commonly in healthcare environments such as hospitals or care homes where patient populations are at higher risk of infection. In the hospital environment, C. difficile is the biggest known cause of infectious diarrhoea in the developed world.7


C. difficile infections are most commonly treated with met*******ole or van****cin antibiotics. Whilst this treatment is effective for most, the disease does recur after therapy in 20% of the outpatient population.8 In these cases, multiple recurrences are common and can be difficult to treat.9 Pioneering techniques such as faecal transplants,

whereby a healthy donor’s faecal matter is transplanted into a C. diff sufferer’s intestinal tract, have shown initial success in those with multiple recurrences of the disease. (Read our news piece on faecal transplants).

microscopic c.diff

Scientific research on probiotics and C. difficile

A number of studies show that Saccharomyces boulardii may protect against infection and gastrointestinal inflammation induced by C. difficile.10,11,12 One randomised, placebo controlled study revealed that S. boulardii, in combination with a standard oral antibiotic, may be more effective in decreasing the likelihood of C. difficile recurrences than standard therapy alone. The efficacy of S. boulardii was significant with a recurrence rate of just 34.6%, compared with 64.7% on placebo.13 In-depth research has also elucidated the mechanism of action of S. boulardii against C. difficile. Studies have shown that S. boulardii may interfere with the pathogenic process of C. difficile by releasing a 54kDa protease; which may inactivate C. difficile toxins A and B and lyse colonic receptors.14,15 Furthermore, Saccharomyces boulardii is also known to stimulate the host’s intestinal mucosal immune response, by stimulating an increase in secretory IgA.16, 17

In addition to the S. boulardii probiotic yeast, results from other clinical trials suggest that bacterial probiotics could also offer benefits for those suffering with Clostridium difficile infection (CDI).

One such randomised controlled trial monitored 33 patients who were suffering from mild to moderate Clostridium difficile infection. Patients in the intervention group were administered with a combination of four different probiotic strains: Lactobacillus acidophilus NCFM®Lactobacillus paracasei Lpc-37®Bifidobacterium lactis Bi-07® and Bifidobacterium lactis Bl-04®. The probiotic supplement had a strength of 17 billion CFUs, and was given over a 28 day period alongside standard antibiotic treatment. Patients in the control group were given a placebo.

The results of the study showed a reduction in the duration of the infection in the probiotic group, where symptoms (typically diarrhoea) were reduced by an average of 24 hours. As patients with C. difficile are often very ill, any reduction in the duration of their symptoms is extremely significant, as the infection can significantly lower their chances of survival and can also increase the risk of infection in other patients. The incidence of C. diff infections also places a financial and practical burden on hospitals, so any safe and viable solution to conventional treatment will be welcomed by hospital administrators and staff.

Another, double-blind study observed 44 critically ill patients with aim of assessing the positive benefits of another strain, Lactobacillus plantarum 299v® (LP299v®), on the incidence of C. difficile infection. The study was randomised, and subjects were to be given either a dose of LP299v® or a placebo. In the placebo group there was a 19% incidence of C. difficile infection, whereas in the probiotic group, none of the patients contracted C. difficile infection.18

You can also have a look at our new Probiotics Database for further research on probiotics and C. difficile.

Article updated: 20/07/16

Article edited: 19/09/17


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