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Thursday 14 February 2008

RAPID ROUNDUP: Probiotics - New research findings

Probiotics are often promoted to be the be-all and end-all of good digestion. The are sold as yoghurts, drinks and other products containing large numbers of live ‘friendly’ bacteria. Today two new pieces of research have been published on the effects of taking probiotics.

Australian research published today in the British Journal of Sports Medicine has shown that a strain of the probiotic Lactobacillus can substantially cut the rate and length of respiratory illness in professional long distance runners. The researchers found that athletes taking the probiotic had less than half the number of days of symptoms of their colleagues taking the placebo. We have rounded up some comments from Australian experts.

In a separate study published today in the Lancet, researchers have found that probiotics are associated with an increased mortality in patients with severe acute pancreatitis, and do not reduce the risk of infectious complications in these patients. Below are comments from an Australian scientist plus two from UK experts (compiled by the UK SMC).

Feel free to use these comment below in your stories. If you would like to speak to an expert, or need a copy of the papers and media releases, please don’t hesitate to contact us on (08) 8207 7415 or by email.

Probiotics cut respiratory illness rates in athletes

Dr David Pyne is one of the study’s authors and is from the Department of Physiology, Australian Institute of Sport, Canberra, Australia

“This was a preliminary study examining the effects of probiotic supplements in athletes undertaking high level training. This is part of a broader range of research on the health benefits of nutritional interventions both in the general community and specific populations with high energy jobs, like athletes, military personnel and emergency services workers. There is a great deal of interest in nutritional supplements in the general community as well the sporting community, from coaches and athletes, and researchers and clinicians. Most people are aware of the purported benefits probiotics particularly through the marketing and advertising of yoghurts and probiotic supplements. We were keen to determine how effective these types of supplements are in highly trained athletes. Most of the work conducted on probiotics has focused on infant formula preparations and there is less research on their effects in adults, particularly in elite athletes and other highly active individuals”

In this study, the experimental group receiving the probiotic Lactobacillus fermentum had fewer days with illness symptoms. This is an encouraging clinical outcome but we are still exploring the mechanisms to explain this. We are currently planning further work with our university, government and industry partners in this area.

The two most important qualities of probiotics are the strains of bacteria used and the dosage. Many people would be familiar with the strain Lactobacillus acidophilus that is commonly used in yoghurt. However in this research we used a slightly different strain called Lactobacillus fermentum, which is sold in Australia as Probiomics PCC. There is substantial research activity in the effectiveness of different probiotics strains, dose response issues, and the shelf-life of products. Some research shows that the longer products are on the shelf the more degradation of the good bacteria you get. These are commercial issues that still need to be addressed through research and product development.”

Dr David Topping is a Senior Research Scientist with CSIRO Food Futures and Preventative Health Flagships

“This looks like promising research and supports what has previously been seen with prebiotic treatment in young children where the incidence and severity of chest infections was reduced. Elite athletes and people doing high level physical activity do appear to be at greater risk of gut infections and related conditions where immune functions may be compromised. Whether this applies to the population at large remains to be determined but it is part of a body of increasing evidence, that control of the gut microbiology is important in the maintenance of general health and may assist in a range of conditions where the immune system is compromised like infections and respiratory disease.”

Probiotics increase mortality in patients with severe pancreatitis

Dr David Topping is a Senior Research Scientist with CSIRO Food Futures and Preventative Health Flagships

“Acute pancreatitis is clearly a life threatening condition and represents a very advanced disease. The use of probiotics to treat that conditions is quite different to the moderate consumption of probiotics to assist in the maintenance of normal gut function.”

UK SCIENCE MEDIA CENTRE UK RAPID ROUNDUP:

Professor Glen Gibson is from Food Biosciences at the University of Reading, UK

“For years and years good probiotics have had an excellent track record of success and safety. Hence, to see them associated with mortality as is the case here is contrary to hundreds of other research publications. We foresee no reasonable explanation for the deaths and stress that the study population was a group of very ill people. It cannot be ruled out that the increased fatalities were because of the condition not the use of probiotics.

“To see conclusions associating probiotics INCREASING mortality without any viable explanation of this is – to me – nonsense. Moreover, assuming that all probiotics act as one is equally as poor.”

Professor Robert Sutton is Supra-Regional Pancreatic Service at the Royal Liverpool University Hospital, UK

"Severe acute pancreatitis is a common, severe and life-threatening illness largely due to gallstones or alcohol excess that has no satisfactory specific treatment. Probiotics are safe and may be beneficial in many people who are not critically ill, but this new study shows that probiotics should not be given to patients with severe acute pancreatitis."