Cranberries have long been hailed a 'superfood' for their cancer-fighting properties but now they have been proven to benefit our gut health, say experts.

For the first time, certain friendly microbes have been found to grow when fed a carbohydrate in the fruit.

Good intestinal bacteria not only improves digestion but also our brain health, mood, emotions, energy levels, and weight loss.

Whats more, our microflora has also increasingly been linked to many aspects of health, including aging, arthritis, depression, cancer and heart conditions.

Now cranberries – in supplement form – may be a candidate to improve our gut health, says study author professor David Sela, nutritional microbiologist at the University of Massachusetts Amherst.

Xyloglucans, the special sugars found in cranberry cell walls, are said to benefit gut health

He said: 'They make molecules and compounds that help us, or they make it to help some of the hundreds of other kinds of beneficial members of the [gut health] community.

'There are thought to be as many bacterial cells in our bodies as our own human cells, so we're basically eating for two.

'These gut bacteria are extremely significant to us, they really are very important. Our food makes a difference for us as well as the beneficial microbes that we carry around with us.'

Key findings

Professor Sela and his team set out to test their theory that xyloglucans, the special sugars found in cranberry cell walls, can be broken down by beneficial bacteria into healthy compounds for the gut.

CRANBERRIES COULD HELP FIGHT BOWEL CANCER Cranberries could be key to combating bowel cancer, according to previous study. The disease kills almost 16,200 people in the UK each year. Researchers generated three powdered cranberry extracts – a whole fruit powder, another containing only chemicals from the cranberry known as polyphenols, and a third with only the non-polyphenol components of the fruit. The extracts, equivalent to a cup of cranberries a day, were mixed into the meals of mice with colon cancer. After 20 weeks the mice given the whole cranberry extract had about half the number of tumours as mice that received no cranberry in their food. The remaining tumours in the cranberry-fed mice were also smaller. Furthermore, the cranberry extracts appeared to reduce the levels of inflammation markers in the mice. The research came from the University of Massachusetts Dartmouth. Advertisement

However, a lot of plant cell walls are indigestible, including xyloglucans, and therefore cranberries eaten naturally do not leave their mark on gut microbe in this way.

So in the lab, the experts directly fed this purified plant sugar as the only carbohydrate to bifidobacteria, a group of bacteria that normally live in the intestines.

The team found that certain bifidobacteria do consume xyloglucans and grow.

These probiotics are found in adults to some degree but the highest concentrations are found in the guts of newborn, breast-fed babies, explains professor Sela.

'They are consuming things we can't digest, or they are helping other beneficial microbes that we find it hard to introduce as probiotics, or their presence can help keep pathogens away,' he said.

It is not clear yet what the impacts to health are but the findings are promising.

'Prebiotics and probiotics might interact with our own physiology to help balance the microbiome, and we already know that when things are not in balance you can get problems like inflammation,' he added.

'Underlying chronic inflammation can lead to or worsen many different medical conditions.'

Professor Sela hopes to carry out further studies on how cranberry xyloglucans interact with other bacterial species and strains.