Science - September 23, 2010

Yakult on doctor's orders

Probiotic drinks such as Yakult and Vifit change the activity of hundreds of genes in the intestines in a way that is sometimes very similar to the effect of certain medicines. This opens up possibilities for using probiotics to combat certain diseases.

Lactobacillus bacteria
This conclusion is outlined by doctors, microbiologists and geneticists at the Universities of Maastricht and Wageningen, the St. Radboud University Medical Centre in Nijmegen, and NIZO Food Research in a study published last week in the prominent journal PNAS (Proceedings of the National Academy of Sciences).
Communication 
There is an intimate and mutually beneficial relationship between human beings and Lactobacillus bacteria, of which there are billions in probiotic drinks. The bacteria live off the nutrients in our intestines, at the same time helping their host with digestion. As in every relationship, good communication is essential. Between humans and probiotics this dialogue takes place at molecular level. 'It has been known for some time that Lactobacillus bacteria can change the activity of hundred of genes in intestinal cells', says author Michiel Kleerebezem of NIZO Food Research and Laboratory for Microbiology. 'We wondered whether that changed gene activity might have anything to do with the health-promoting effects previously reported.'
 Medicines
To find this out, seven test subjects were given either a different probiotic drink or a control drink every two weeks. Three probiotic drinks were tested. Six hours after the drink had been consumed, doctors removed a small sample of the mucous membrane in the intestine, in which they could analyse the activity of thousands of genes.
The researchers compared their results with those in a database containing the gene expression effects of countless medicines. 'The response to the probiotic drinks appears to be very similar to the response to certain medicines such as anti-oxidants, drugs for reducing blood pressure and anti-inflammatories', says Kleerebezem. 'There might be a role for probiotic drinks in the development of new or alternative therapies.'

Gut problems
Does it mean we can chuck out our medicines and start knocking back probiotic drinks instead? Certainly not, says the researcher. 'Medicines often have a powerful effect and work through the blood, reaching the entire system. Probiotics have a milder and more local effect on the intestines', he explains. 'That will probably be the limiting factor in their use.' Yet it is possible to imagine clinical uses for the drinks. Kleerebezem: 'Marathon runners often get gut problems during races due to reduced circulation in the intestinal wall. Our research suggests that they would benefit from a little bottle of probiotic drink.'

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