Irish scientists have discovered a link between gut micro-organisms and Alzheimer’s disease.
For the first time, researchers have found that Alzheimer’s symptoms can be transferred to a healthy young organism via the gut microbiota, confirming its role in the disease.
The research was led by Yvonne Nolan, professor in anatomy and neuroscience at University College Cork and researcher with APC Microbiome Ireland, and conducted by postdoctoral researcher Dr Stefanie Grabrucker, in collaboration with research teams at King’s College London and the IRCCS Fatebenefratelli Institute in Italy.
The study, published in the journal Brain, identified links between gut bacteria, inflammation and brain changes associated with Alzheimer’s disease. The researchers showed that the memory impairments in people with Alzheimer’s could be transferred to young animals through transplant of gut microbiota.
Alzheimer’s patients had a higher abundance of inflammation-promoting bacteria in faecal samples, and these changes were directly associated with their cognitive status.
“We saw that animals with gut bacteria from people with Alzheimer’s produced fewer new nerve cells and had impaired memory,” Prof Nolan said.
“People with Alzheimer’s are typically diagnosed at or after the onset of cognitive symptoms, which may be too late, at least for current therapeutic approaches. Understanding the role of gut microbes during prodromal – or early stage – dementia, before the potential onset of symptoms may open avenues for new therapy development, or even individualised intervention.”
The new research is the latest in a recent surge of medical breakthroughs providing hope for clinicians and patients in the race to understand and treat Alzheimer’s disease.
In July the US Food and Drug Administration approved the use of lecanemab as a disease-modifying treatment for Alzheimer’s disease. The drug lowers beta-amyloid in the brain and reduces cognitive and functional decline in people living with early stages of the disease.
In recognition of this milestone, the drug has been named by Time magazine as one of the 200 best inventions of 2023.
However, questions have been raised as to how the health service here will be able to afford the new treatment should it receive European approval next year as expected.
At a recent meeting of the Joint Oireachtas Committee on Health, Secretary-General at the Department of Health Robert Watt said that the treatment of 4,000 patients with lecanemab could cost the State €100 million annually.
The HSE’s pharmaceutical budget has doubled in the past ten years, from €1.3 billion in 2012 to €2.6 billion last year. Including payments to contractors such as pharmacists, spending on medicines is set to reach €3.2 billion this year.
“This level of growth is clearly not sustainable and we need to strive to maximise the available investment to provide as many people as possible with access to these medicines,” said Mr Watt, pointing to the greater use of generic and biosimilar medicines as a way to address high costs.