Inflammatory bowel disease (IBD) is a general term that covers several conditions in which the intestine is persistently inflamed. The two main forms of IBD are Crohn's Disease and Ulcerative Colitis (UC). IBD should not be confused with IBS (irritable bowel syndrome), a completely separate condition in which the intestine is not damaged.
Crohn's and UC are long-term conditions that, although mostly starting in young adults, can start at any age. The main symptoms are diarrhoea, pain and blood in the stool, and currently there is no cure. Treatments include a range of drugs that reduce the inflammation and, in severe cases, surgery to remove damaged intestine.
Recently, it has become clear that these diseases centre on the immune cells and tissues in the intestine reacting incorrectly to the normal gut microflora.
The gut microflora
The gut microflora are billions of bacteria that live in the intestine of each human being. These bacteria are usually harmless and help to stop disease-causing bacteria becoming established.
People with Crohn's and UC have a different mixture of bacteria in their microflora compared with people who have no intestinal disease. There are fewer of the beneficial bacteria (such as lactobacilli and bifidobacteria) and more of potentially harmful types. This imbalance has led researchers to wonder if changing the balance, by increasing the numbers of the better bacteria, may reduce the severity of IBD.
The method used to test this idea is the consumption of probiotics, which are products containing large numbers of beneficial bacteria.
Food products containing beneficial bacteria
The idea of consuming bacteria may seem strange, but this has been happening for thousands of years in the form of fermented foods, particularly soured milks and yoghurts. The foods were known to be healthy, but it was not until the nineteenth century that scientists learnt that they contained beneficial bacteria. A Nobel Prize winner, Professor Elie Metchnikoff, studied these bacteria at the Pasteur Institute in Paris, and concluded that they improved the general health of those who took these products regularly.
During the twentieth century, modern manufacturing techniques were used in a consistent way to produce yoghurt-type products, Italian hard sausages and German sauerkraut.
Beneficial bacteria to counteract disease
The thought that such beneficial bacteria could be used to counter the effects of specific disease was not given much attention by scientists in the twentieth century because antibiotics had proved so effective in tackling bacterial diseases. With the overuse, and sometimes misuse, of antibiotics, resistant strains of bacteria started to appear and concerns were raised as to the continued effectiveness of antibiotics. Thought is now being given to alternative approaches, including the use of beneficial bacteria to counteract harmful bacteria.
The beneficial bacteria, now called probiotic, were first adopted by the veterinary profession, initially for farmed animals and subsequently for pets. The medical profession remained more sceptical, but as the number of positive scientific studies pointed to the benefits of probiotics, doctors have become more receptive to the idea.
Current research shows benefit in the following conditions:
Infectious diarrhoea (especially following antibiotic use)
Eczema in children
Urogenital disease
Inflammatory bowel disease
Evidence in IBD
Well-structured clinical trials, published in prestigious medical journals, have shown probiotic products reducing the severity of UC and Crohn's Disease. The evidence for benefit in Crohn's is weaker, as there have been fewer studies than for UC. There is excellent evidence for the benefit of probiotics in pouchitis (inflammation of the ileo-anal pouch, a surgical replacement of the large intestine).
Most of the clinical studies of probiotics in IBD have involved the initial administration of antibiotics, to reduce the numbers of bacteria in the microflora. This is then followed by the consumption of billions of probiotic bacteria. In most cases, the patients were in remission at the time of the study and, compared with a control group (not receiving the probiotic), the proportion of people remaining in remission was significantly higher in the group receiving the probiotic.
It may be that probiotics will also be helpful against active IBD, but not enough good quality studies have been undertaken so far to know.
Types of probiotics
Most good quality studies of probiotics in IBD have used freeze-dried bacteria. These are in a form of a suspended animation and with the addition of water they become active again.
The main criteria for a good probiotic are:
A large number of probiotic bacteria (highly concentrated)
Packaged and stored so that there is a minimal reduction in numbers of live bacteria from the time of production e.g. encapsulated and in blister packs.
Protection from the effects of stomach acid, either by special coatings or by the use of acid-resistant strains of bacteria
Fermentable food (such as prebiotics) mixed with the probiotic bacteria to help them live and grow as they travel through the intestine
Containing species and strains that can attach themselves to the lining of the colon, to enable them to reproduce more easily and have a greater effect
Containing species and strains for which there is some scientific evidence of health benefit
A mixture of probiotic species (multi strain), rather than just one species, to increase the likelihood of there being a significant effect.
Research on probiotics is being undertaken throughout the world and the benefits to human health, including reducing the severity of IBD, are becoming much clearer. There is good reason to be hopeful for the future. Current information is sufficient to warrant discussing with your doctor the potential benefits of probiotics.
Peter Cartwright
Author, Probiotics for Crohn’s and Colitis
www.prentice-publishing.co.uk
