Daily fibre supplement improves older adults' brain function, study suggests

A daily fibre supplement could help improve brain function in over 60-year-olds in just 12 weeks, new research suggests.

The study showed that the simple and cheap addition of prebiotics – plant fibres that help healthy bacteria grow in your gut – to diet can improve performance in memory tests associated with early signs of Alzheimer’s disease.

However, the supplements – inulin and  Fructo-oligosaccharides (FOS) – were found to have no effect on muscle strength over the three months.

First author Dr Mary Ni Lochlainn from King’s College London, said: “We are excited to see these changes in just 12 weeks.

“This holds huge promise for enhancing brain health and memory in our ageing population.

“Unlocking the secrets of the gut-brain axis could offer new approaches for living more healthily for longer.”

Researchers at TwinsUK, the UK’s largest adult twin registry based at King’s College London, looked at how targeting the microbiota – the microorganisms in the intestines – could have an impact upon both muscle health and brain function.

Thirty-six twin pairs – 72 people – over the age of 60 years were given either sachets of a dummy supplement or the actual supplement every day for 12 weeks.

Everyone in the study also carried out resistance exercises and ate a protein supplement which was aimed at improving muscle function.

After monitoring the group remotely via video, online questionnaires and cognitive tests, researchers found the fibre supplement led to significant changes in the make up of a person’s gut microbiome (bacteria).

According to the study, published in Nature Communications, there was a particular increase in the numbers of beneficial bacteria such as Bifidobacterium.

The group receiving the fibre supplement did better in brain function tests, including the Paired Associates Learning test which is an early marker for Alzheimer’s disease, together with tests of reaction time and processing speed.

Researchers suggest these measures are important for everyday activities like reacting to traffic or stopping a simple trip-up turning into a fall.

Senior author Claire Steves, Professor of Ageing and Health at King’s College London, said: “These plant fibres, which are cheap and available over-the counter, could benefit a wide group of people in these cash-strapped times.

“They are safe and acceptable too. Our next task is to see whether these effects are sustained over longer periods and in larger groups of people.”