Critical Appraisal Topic
June 20, 2015
Darcy Subramaniam
Irritable Bowel Syndrome (IBS) is a common gastrointestinal condition characterized by abdominal
bloating, flatulence, abdominal pain and bowel dysfunction (Butturo, 2013) There appears to be a
correlation between abnormalities in the GI tract motility, alterations in autonomic regulation,
sensitivity in abdominal viscera, brain-gut interaction abnormalities and changes in the GI flora. The
ROME III Criteria can be used to diagnose Irritable Bowel Syndrome.
Case Presentation
A 46-year-old female presents to your office with complaints of bloating, gas and abdominal pain. She
was diagnosed with Irritable Bowel Syndrome about 20 years ago and is looking for alternative
treatments to managing her symptoms. She feels that she has tried many different things and is
wondering about adding probiotics to her diet.
PICO question
In patients with irritable bowel syndrome (P), how does regular ingestion of probiotics (I) compare to no
intake of probiotics (C) in regards to the symptoms of irritable bowel syndrome (O)?
Summary and Appraisal of Key Evidence
The first article reviewed is a peer reviewed paper by the British Dietetic Association which 1163 papers
were reviewed with 30 papers meeting the question criteria. Studies that were included were individual
intervention studies and systematic reviews. It is stated that probiotics may improve IBS symptoms by
altering the integrity of the gut mucosa to decrease intestinal permeability and in turn decrease mucosal
inflammation and immune stimulation. The studies reviewed in this article list weak evidence to
support Bifidobacteriumlactis DN 173010 and weak evidence to support the use of combination
probiotics: Bifidobacterium (Bifidobacterium lungum, Bifidobacterium infantis, Bifidobacterium breve),
Lactobacillus (Lactobacillus casei, Lactobacillus bulgaricus, Lactobacillus plantarium) and Streptococcus
(Streptococcus salivarius sub sp thermophilus). This study is limited to the British Dietetic Association
and would benefit if it was taken internationally to improve applicability.
Another peer review article reviewed included 28 double-blind, placebo-controlled randomized trials for
the article. This article states that effective treatment may be masked by the grouping or sub-grouping
of IBS. Strains of probiotics that show good results include bifidobacteria, lactobacilli, E. coli and
mixtures of different bacterial strains. Bifidobacteria infantis 35624 and Lactobacullus plantarium 299v
also show promising results individually, although have not been studied in combination or given as a
cocktail. The article states this area of study would possible benefit patients with IBS. This article also
states that the US Food and Drug Administration does have regulatory authority over probiotic products
and regulates manufactures responsibilities with regard to labeling, safety whether in food, supplement
or drug form. It is stated that there is a need for further research to determine the underlying
mechanism of action of specific probiotics to help determine which specific organism is most likely to
benefit a specific disease condition.
Clinical Bottom Line:
Mckenzie, et.al. (2012) recommends that probiotics be used as a second-line dietary intervention. Each
probiotic should be used for 4 weeks to have a true assessment of decreasing of symptoms. Also it is
alerted that some probiotic products may contain ingredients that may aggravate IBS, fructans, polyols,
fructose and lactose. After four week of use of a particular probiotic, with improved symptoms the
probiotic should be continued. Stevenson & Blaauw (2011) state that functional foods may provide an
alternative to the pharmaceutical approach to IBS.
References:
Buttaro, T., Trybulski, J., Polgar Bailey, P., & Sandberg-Cook, J. (2013). Primary care: A collaborative
practice (4th ed.). St. Louis, Mo.: Elsevier/Mosby.
Mckenzie, Y., Alder, A., Anderson, W., Wills, A., Goddard, L., Gulia, P., Jankovich, E., Mutch, P., Reeves,
L.B., Singer, A., Lomer, M. (2012). British Dietetic Association evidence-based guidelines for the
dietary management of irritable bowel syndrome in adults. Journal of Human Nutrition and
Dietetics, 25, 260-274. doi:10.1111/j.1365-277X.2012.01242.x
Stevenson, C., & Blaauw, R. (2011). Probiotics, with special emphasis on their role in management of
irritable bowel syndrome. South African Journal of Clincial Nutrition, 24(2), 63-73.