Health / Health News |
Changes in human microbiome precede Alzheimer’s cognitive declines
While pinpointing the exact causes of Alzheimer’s remains a major research challenge, they likely involve a combination of genetic, environmental, and lifestyle factors.
A new study elucidates the role of another likely culprit that you may not have considered: the human gut microbiome, the trillions of diverse bacteria and other microbes that live primarily in our intestines.
Earlier studies showed that the gut microbiomes of people with symptomatic Alzheimer’s differ from those of healthy people with normal cognition.
What’s exciting about this finding is it raises the possibility that doctors one day could test a patient’s stool sample to determine if what’s present from their gut microbiome correlates with greater early risk for Alzheimer’s dementia.
Such a test would help doctors detect Alzheimer’s earlier and intervene sooner to slow or ideally even halt its advance.
The new findings come from a research team led by Gautam Dantas and Beau Ances, Washington University School of Medicine in St. Louis.
The researchers found that those with preclinical Alzheimer’s had markedly different assemblages of gut bacteria. Their microbiomes differed in many of the bacterial species present.
Those species-level differences also point to differences in the way their microbiomes would be expected to function at a metabolic level.
These microbiome changes were observed even though the individuals didn’t seem to have any apparent differences in their diets.
The team also found that the microbiome changes correlated with beta-amyloid and tau levels in the brain. But they did not find any relationship to degenerative changes in the brain, which tend to happen later in people with Alzheimer’s.
The team is now conducting a five-year study that will follow volunteers to get a better handle on whether the differences observed in the gut microbiome are a cause or a consequence of the brain changes seen in Alzheimer’s. (National Institutes of Health)