Symptoms of Irritable Bowel Syndrome (IBS) are varied but usually include one or more of the following:
- bloating
- abdominal cramping
- constipation
- diarrhoea
Constipation or diarrhoea are usual, and some sufferers experience both.
The cause of IBS is unknown, but thankfully, it doesn't seem to cause lasting damage to the digestive tract. The one thing that you can be sure of, though, is that it does cause irritation and annoyance!
The rise of probiotics
Probiotics are beneficial bacteria that inhabit the digestive tract. They aid digestion, stimulate immunity and help to keep potentially harmful organisms at bay.
Aside from supplementation, the main sources of probiotics are cultured milk products, such as yoghurt and buttermilk.
Examples of commonly available probiotic species in food and supplemental form include: Lactobacillus acidophilus, Bifidobacterium animalis, Bifidobacterium infantis, Lactobacillus rhamnosus and Lactobacillus reuteri.
Probiotics in supplemental form are now found in nearly every health food store and pharmacy across the country.
What does the science say?
There has been a growing interest in the use of probiotics in IBS over the last few years in the scientific community.
A systematic review published in February 2009 assessed 14 randomised, placebo-controlled trials that varied in treatment length (4-26 weeks), dose, and species/strain of probiotics.
The primary outcome measure was overall improvement in the following symptoms: pain, flatulence, bloating, anxiety and quality of life.
The authors wrote that the combined data suggested a moderate improvement in overall symptoms after several weeks of treatment.
Systematic reviews from 2008 have made similar claims about the emerging role of probiotics in treating symptoms of IBS.
Spiller (2008) concluded that several well designed and large randomised, placebo-controlled trials showed an improvement in flatulence and abdominal distension, while Wilhelm et al (2008) found that half of the blinded controlled trials assessed indicated a significant improvement in symptoms versus placebo.
Four factors that may trigger IBS:
- Infection – after a gastrointestinal infection, symptoms may persist long after the bad bugs are gone. The reason is unknown but could include changes in nerve function or bacterial flora.
- Certain foods – poor absorption of lactose and fructose, spicy foods and low fibre diets are potential IBS triggers.
- Stress – anxiety in particular can affect the nerves in the bowel.
- Medications – side effects of some medications may contribute to IBS symptoms.
Did you know?
- Irritable Bowel Syndrome is more common in females.
- Probiotics may relieve the symptoms of flatulence in IBS sufferers by affecting the fermentation processes in the bowel so less gases are produced.
- Foods other than yoghurt that can support probiotic activity include: miso, tempeh, kefir, kombucha, bananas, garlic and onions.
BMC Gastroenterology. 2009; 9:15
Am J Gastroenterol. 2009; 104:1033-1049
Aliment Pharmacol Ther. 2008; 28:385-396
Pharmacotherapy. 2008; 28(4):496-505
Other references available on request