Ageing Gut Brain Interactions

This research project will address a desperate need for evidence on how diet could be used to treat and improve symptoms of Alzheimer's disease (AD). It has been estimated that 36 million people have dementia worldwide, and in older people Alzheimer's disease accounts for 60-70% of all dementia. Research supports the hypothesis that modifiable lifestyle-related factors are associated with cognitive decline, which opens new avenues for prevention or modification of disease. The concept that inspires this proposal 'Ageing-Gut-Brain Interactions study' is that the gut microbiota impact upon the gut-brain axis and thereby on behaviour, including challenging behaviours often associated with dementia. In the absence of available cures for Alzheimer's disease, diet is an important modifiable component but knowledge about the role of diet in clinical symptoms of dementia is currently very limited. A recent study from Ireland from the European Union funded Nu-Age cohort reported that the gut microbiota profile in the elderly was different between community-living and institutionalized individuals, with specific microbiome profiles correlating with frailty and poor health. Changes in dietary composition and diversity were considered the main drivers of the shifts in gut bacteria profile. In this multi-disciplinary research study, the investigators will assess the gut microbiota composition in people with Alzheimer's dementia with and without challenging behaviours; test the feasibility of recruitment; and provide initial data to support a future grant application involving a dietary intervention study in patients with Alzheimer's disease. The investigators will test the hypothesis that the gut-brain axis promotes behavioural changes in Alzheimer's dementia and is responsive to changes in gut microbiota profile, by comparing the gut microbiota profile between three participant groups (1) Alzheimer's dementia with challenging behaviour, (2) Alzheimer's dementia without challenging behaviour, and (3) a control group of healthy age-matched elderly. The investigators will also carry out a survey of care homes to assess willingness to participate in a future dietary supplementation study.