We should stop washing our hands as often to protect ourselves against allergies and food intolerances, experts suggest.

This would encourage helpful bacteria - essential for regulating the immune system - into the body.

American scientists say these microbes are vanishing from our guts because of a huge reduction in the amount of fibre in our diets.

Bacteria live primarily on fibre and people today eat just a tenth of the roughage consumed in hunter-gatherer societies.


Widespread antibiotic use, caesarean sections and less-frequent breastfeeding in industrialised nations could also account for the depletion of intestinal microbes.
Many experts believe the fall in microbes has fuelled a rise in allergies and food intolerances.

"Simple tweaks in our cultural practices, for example, not washing our hands after gardening or petting our dogs could be a step in the right direction," said Dr Justin Sonnenburg, associate professor of microbiology and immunology at Stanford University School of Medicine in California.

The researchers used experiments on mice to show that bacterial species vanish with a low-fibre diet, and rarely return.

Two sets of mice - one raised on a low-fibre diet and the other on a high-fibre diet - were studied.

The results showed that within a couple of weeks, there was a 75 per cent reduction in microbial diversity in those on the low-fibre diet - with many species disappearing from the intestines all together.

Dr Sonnenburg added: "The extremely low fibre intake in industrialised countries has occurred relatively recently.

"Is it possible that over the next few generations we'll lose even more species in our gut?

"We would have difficulty living without them. They fend off pathogens, train our immune systems and even guide the development of our tissues."

- Daily Mail