The pros and cons of probiotics

The television advertisement for Actimel probiotic yoghurt drinks—made by French dairy and nutrition giant Danone—featured a bottle of the product gambolling over a skipping rope to the sound of children playing in the background*. The implication that the product would improve the health of “normal” children—without any illnesses, or metabolic disorders such as diabetes or obesity—triggered viewer complaints upheld by the Advertising Standards Authority (ASA).

But there is some history here. Danone has run a series of highly successful campaigns for Actimel, including a poster advert last year featuring Bobby Charlton with the line “I’m supporting my defences this winter—are you?” They have, however, frequently fallen foul of advertising standards. Only last month, Danone settled a class action lawsuit, filed by consumers in California in January 2008, alleging that they had been persuaded to part with their money for products by misleading advertising claims which had never been scientifically proven. As part of the settlement Danone agreed to set up a $35m fund to compensate “qualified consumers” who had bought the product. But there was also a note of defiance, with a statement repeating the claim that the benefits were substantiated by years of scientific research.



The truth, such as we know it, can be summarised thus: some probiotic drinks containing live bacteria strains, including Actimel, confer some benefits on some people some of the time. There is no evidence that healthy people stand to gain from them—if you define “healthy” as those who are physically active, close to optimum weight, and with no significant metabolic or allergic disorder.

Of course, this definition might only extend to a minority of the population, and there is some evidence that probiotic drinks can help otherwise healthy people who develop diarrhoea after a course of antibiotics. The effect of antibiotics can be to decimate healthy gut bacteria and leave the gut open for colonisation by strains such as E.coli. This highlights the main case for Actimel, which is that the lactobacillus strains it contains can aid digestion of some key nutrients, such as lactose in diary products, but in particular helps exclude other undesirable strains that cause illnesses.

However probiotic foods are superfluous in healthy people with an all round diet including sources of “good” bacteria, as well as ingredients these bacteria need for their own nutrition (that is prebiotic ingredients). For many people the health benefits of drinking more water would be greater.

(* This post was amended by Prospect on 15-10-09, in order to refer to "probiotics" rather than "prebiotics" as originally stated)