Taking "good" bacteria known as probiotics may help prevent diarrhoea brought
on by a tough-to-treat infection that often results from taking antibiotics,
according to a fresh look at some past research.
"For older patients that are in hospital or in nursing homes who are exposed
to antibiotics, we've shown that certain probiotic regimens at certain dosages
result in large reductions in the incidence of C. difficile-associated
diarrhoea," said Bradley Johnston, the study's lead author from The Hospital for
Sick Children Research Institute in Toronto, Canada.
People who take antibiotics are at risk for losing some of the good bacteria
that live in their guts, allowing Clostridium difficile bacteria, or C.
difficile, to grow - especially after a stay at the hospital.
The infection's symptoms typically include stomach cramps and diarrhoea. In
severe cases, the colon becomes inflamed.
The US Centers for Disease Control and Prevention estimates about 14 000
American die every year from C. difficile-related diarrhoea.
For the new review from the Cochrane Collaboration, an international research
organisation that evaluates medical evidence, the researchers analysed data from
23 studies that included 4 213 adults and children taking antibiotics.
The studies that were included in the review split the participants into two
groups. One group took probiotics along with their antibiotics, and the other
did not. Overall, Johnston and his colleagues found taking probiotics didn't
change the number of people who went on to develop C. difficile - about 13% in each group.
It did, however, lead to a significant drop in those who had diarrhoea. The
researchers found that only 2% of people who took probiotics developed
diarrhoea related to C. difficile. That compared to 6% of people who
didn't take probiotics.
'It will hurt your wallet - they're not cheap'
Dr Shira Doron, who was not involved with the new review but studies
probiotics, said that the new findings jibe with past research. She said,
however, that the results don't apply to all probiotics.
"Every strain (of probiotics) has traits and mechanisms of actions. I think
it would be wrong to conclude from the systematic review that you could buy any
probiotics off the shelf and take it," said Doron, an associate hospital
epidemiologist at Tufts Medical Center in Boston.
Johnston said two of the probiotics that led to the greatest benefit were
Saccharomyces boulardii and a combination of Lactobacillus acidophilus and
Otherwise healthy patients needed at least 10 billion colony-forming bacteria
per day to see an effect, he said - the amount in 2-4 pills per day. The price
of probiotics varies, but a 30-day supply from the drugstore typically costs
"What I usually tell patients is that it might help and it's unlikely to
hurt. It's generally safe for most patients. It will hurt your wallet - they're
not cheap," Doron added.
But she warned that probiotics probably aren't necessary for someone being
treated at home for an infection unless they've been in and out of the hospital
at some point.
Johnston said it will be important for researchers to do follow-up studies on
the safety of probiotics going forward - especially as hospitals start using