How fruit and veg may help middle-aged people live longer

UCC researchers find prebiotic compound promotes growth of beneficial microbes in gut

Researchers based at UCC have shown “a prebiotic” compound found in fruits and vegetables promotes growth of beneficial microbes in the gut and may prove to be of benefit to middle-aged people in countering ageing effects, especially in the brain.

Middle-age is a time of life where various physiological changes occur and can lead to alterations of brain function, including cognitive impairments. However, the mechanisms underpinning such changes are unclear.

The scientists at the APC Microbiome Ireland, however, have shown that modifying the gut microbes by diet can lessen inflammation in the brain of middle-aged male mice and may positively influence brain ageing and function.

There is growing evidence microbes in the gut can play a key role in regulating brain functions, particularly emotional processing and behaviour. Prebiotics are non-digestible fibres that promote the growth of beneficial bacteria in the intestines.


Inulin is one such prebiotic found in a wide variety of fruits, vegetables, and herbs, including wheat, onions, bananas, leeks, artichokes, asparagus and chicory that is attracting their attention.

"We wanted to see whether an inulin-enriched diet that can modulate the composition of the microbes in the gut could also improve brain health and wellbeing," said Prof John Cryan, who led the research.

“The community of microbes in the gut changes with ageing. Many studies in ageing focus on very old animals and this may be too late to reverse the age-associated changes. We chose middle-age in the hope that we could promote healthy ageing,” he explained.

Their findings suggests prebiotic dietary fibres could be developed as a new strategy to promote healthy ageing by protecting brain function and prevent the adverse effects of age-related neuroinflammation including dementia. “Perhaps in the future new dietary regimes rather than fancy cars or motorbikes is what is needed for that midlife crisis,” Prof Cryan added.

"Our research shows that a diet supplemented with prebiotics reversed microglia activation in the middle-aged mouse brain towards young adult levels. Moreover, this reversing effect was observed in a key region of the brain which regulates learning and memory in the hippocampus," Dr Marcus Boehme said.

“Microglia are the major immune cells in the brain and have shown to be a key player in neuropsychological and neurodegenerative conditions. Moreover, microglia play a crucial role in brain plasticity and cognition.”

Prof Ted Dinan and Dr Harriet Schellekens also contributed to the study published in the leading journal Molecular Psychiatry.

Kevin O'Sullivan

Kevin O'Sullivan

Kevin O'Sullivan is Environment and Science Editor and former editor of The Irish Times