Effects of probiotics on our health

Studies have shown that probiotics can reduce the mean duration of diarrhoea in patients with an infectious form of diarrhoea. There is also some evidence that probiotics may help prevent antibiotic-associated diarrhoea (sometimes antibiotic treatment can disrupt the balance of intestinal bacteria). Research has also shown a beneficial effect in patients suffering from chronic constipation. The role of probiotics in irritable bowel syndrome – a disorder characterised by abdominal pain, excessive flatulence, variable bowel habit and abdominal bloating – is not yet clear, but studies suggest that a regular intake of probiotics may decrease the symptoms in some people. However, further research is still needed.

A frequent claim made on products containing probiotics is that they stimulate the immune system. An increasing number of studies seem to support these claims, but the mechanisms to explain these effects are as yet unclear. Related to this, there is also some emerging evidence that probiotics may help prevent the development of some allergic diseases, such as atopic dermatitis (an allergic skin reaction) in childhood. However, to date research findings have been inconsistent, and more research is needed before firm conclusions can be made.


In summary, there is already some evidence that foods and drinks (such as yogurts and related products) containing probiotics can make a valuable contribution to our daily diet, provided they are consumed regularly and that the bacteria contained are able to reach the large bowel successfully. But as is often the case in nutrition research, more studies are needed to confirm the strength of evidence about these health effects, in particular the mechanisms by which these products act. Probiotics have been consumed safely by millions of people for many years. There have also been a large number of dietary trials in humans investigating the potential health benefits of probiotics, with no reported adverse effects linked to infections. Thus, whilst the benefits of probiotics for our health may require further study, their intake can be considered as safe.