New study supports gut-brain connection in AD
A new study reinforces the gut-brain connection in Alzheimer’s disease (AD), untangling the complex interplay between gut and brain health that could potentially lead to new therapies targeted at manipulating the gut microbiome to treat AD.
In the analysis of data from 1,562 patients from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) cohort, those with AD had increased gut microbiome-produced bile acids which were associated with changes in cognitive decline, reduced brain glucose metabolism, and greater brain atrophy. [AAIC 2018, abstract 26438]
These bile acids were also linked to increased amyloid and tau accumulation in the cerebrospinal fluid (CSF). The new evidence further supports the role of bile acid pathways in AD, said lead investigator Dr Kwangsik Nho from the Indiana University School of Medicine in Indianapolis, US. “Bile acid signaling pathways may lead to the identification of metabolites that are protective against Alzheimer’s,” he explained during the AAIC 2018 press briefing. “If a causal role can be demonstrated in future studies, this [discovery] could foster novel therapeutic strategies for AD.”
A new window of opportunity
“While still in its infancy, gut microbiome research is very exciting since it may give us a new window into why diet and nutrition are so important for brain health,” commented Dr Maria Carrillo, chief science officer at Alzheimer’s Association, Chicago, US, in a statement. “This work may tell us more about how and why ‘good fats’ help keep the brain healthy and will help guide brain-healthy dietary choices.”
She added that if gut bacteria could be proven effective and established as accurate markers of AD or disease progression, they could be a useful and noninvasive screening tool for AD. “We can then identify high-risk patients for clinical trials or track the impact of a therapy. However, we’re only at step one and we don’t know yet exactly what the changes we are seeing mean, whether they are a cause or an effect.”
Investigations into the gut-brain axis as it relates to AD is a “new frontier in science” that may lead to new discoveries in managing AD, said briefing moderator Dr Martha Clare Morris from Rush University in Chicago, Illinois. She added that diet used to be an important risk factor for AD development. “But the new field of research is uncovering how eating patterns may be related to brain health and dementia.”
What’s in the pipeline for AD
Morris said the Alzheimer’s Association took a step further by funding a new research, the US Study to Protect Brain Health Through Lifestyle Intervention to Reduce Risk (US POINTER), to investigate whether the combination of healthy diet, exercise, cognitive and social stimulation, and management of cardiovascular conditions could prevent cognitive decline and AD.