It’s ‘highly likely your probiotics are useless’

TENS of thousands of people down a probiotic drink every day in the belief that it helps their digestion.

But a new study suggests they may be ineffective for more than half of those who drink them.

Probiotics are said to contain ‘friendly’ bacteria which restore the natural balance of bacteria in the gut. It is claimed they can reduce hayfever symptoms, prevent stomach bugs for people travelling abroad and even stop colds from lasting too long.

As well as drinks, they are often found in yoghurts. But when 19 people in the study conducted in Israel took probiotics containing 11 of the most common strains of bacteria, only eight had any ‘notable colonisation’ of their gut by the bacteria in the probiotics.

Professor Eran Segal, from the Weizmann Institute of Science in Tel Aviv, said: ‘People have thrown a lot of support to probiotics, even though the literature underlying our understanding of them is very controversial. Surprisingly, we saw that many healthy volunteers were resistant. The probiotics couldn’t colonise their tracts.’

To test the probiotics, volunteers were given endoscopies – a tube from the mouth to the stomach – and colonoscopies, involving a tube along the large intestine, to remove and analyse gut bacteria. It seems many were ‘resisters’ to probiotic drinks and the probiotic bacteria were ‘pushed out’ by their existing gut bacteria.

The results are in the medical journal Cell.