Doctors Orders: Our view on current medical issues

The Probiotic conundrum

PROBIOTICS — Good, bad or indifferent.

When one goes into a pharmacy nowadays one is confronted with rows of “health” products that all promise to make you healthier, thinner, younger and more beautiful.  The list is endless and confusing; if the last one did not work there is always a new one to try.


Probiotics are amongst this list and are frequently recommended by those who sell them. But what is the evidence to support their use? Medicine to day tries to be rational and “evidence based”. That means that there should be clear proof that a product does what it claims to do.  What is the evidence that probiotics are good for us?

We live in an environment where we are surrounded by germs (microbes, including bacteria viruses and yeasts) of various sorts, both outside and on the inside of our body.  Many of these are harmless and some bacteria, particularly in our intestine, are helpful in aiding digestion. The word probiotics was introduced some years ago to describe a large group of bacteria that were alleged to be helpful to normal body function and to be protective of health.  The term “probiotic” is vague but sounds so good (in contrast to antibiotics) that they must be good for you.

Probiotics have been marketed as treatment for a variety of problems including irritable bowel syndrome –IBS (spastic colon), inflammatory bowel disease–IBD, diarrhoea, candida infections, and allergies. Many claims have been made for the benefits of these “good bacteria” but little has been proven.  The United States Food and Drug Administration,  the watchdog body that monitors and licences all medical products in the USA, has not approved the use of probiotics for the treatment of any medical condition.  A recent study in the journal Gastroenterology (March 2013) on the use of probiotics for irritable bowel associated diarrhoea found them to be of be no benefit.

Another study in May this year (Cochrane Database) showed that probiotic use reduced the chance of getting severe antibiotic associated diarrhoea by 60%.

Some studies in the Journal of Allergy (2012) have shown that mothers who take probiotics in pregnancy may reduce the risk of their baby having eczema in their first year after birth.  Another limited study (J. Ped. Oto.2012) showed that probiotics improved hay fever symptoms in some children. A recent study funded by yogurt producer Danone (Gastroenterology 2013) showed some experimental changes on scanning the brains of women who took probiotics regularly. It is not clear if these changes are of any significance.

Do probiotics lower cholesterol? The evidence is conflicting and there is no clear answer as yet. (J. Clin. Lipidology 2012).

A possible reason for the conflicting results is the variety of probiotics used, some of these bacteria may be better than others, and the different doses used. The research is on-going and their real value may become clearer in the future.

At this stage it seems that some may be helpful, particularly in reducing the chance of antibiotic associated diarrhoea but little else is proven.   At worst they seem to be safe and relatively inexpensive. There is little evidence to show that any one probiotic is better- so choose the cheapest one.

So should you take a probiotic? -it depends on who you ask. At best they seem safe and may reduce your chance of getting diarrhoea if you are taking an antibiotic. Apart from that the jury is still out.