A new study found an apparent link between Alzheimer's disease and gut disorders including reflux and ulcers -- but not inflammatory bowel disease. Photo by derneuemann/Pixabay
July 18 (UPI) -- People with some gut disorders may be at greater risk of developing Alzheimer's disease, according to a new study that scientists said confirms the genetic link between the two.
The findings by researchers at Edith Cowan University in Perth, western Australia, were published Monday in Communications Biology.
In their paper, the scientists said they found "a positive significant genetic overlap and correlation" between Alzheimer's disease and gastroesophageal reflux disease, known as GERD, peptic ulcer disease, gastritis-duodenitis, irritable bowel syndrome and diverticulosis -- but not inflammatory bowel disease.
Abnormal levels of cholesterol were shown to be a risk for both Alzheimer's disease and gut disorders, the study said.
The study's findings suggest that cholesterol-lowering medications known as statins -- by helping reduce inflammation and protect the gut -- could be beneficial in treating Alzheimer's disease, the most common form of dementia, and gastrointestinal tract disorders.
But further study is needed to determine the potential benefits of such statin use, the scientists noted.
They also noted that diet could play a role in treating and preventing Alzheimer's disease and gut disorders.
The Mayo Clinic lists several statins available for use in the United States, including Atorvastatin (Lipitor) and Lovastatin (Altoprev).
While some people have reported memory loss and thinking problems after using statins, the Mayo Clinic says, studies to date haven't found evidence to prove statins cause these issues -- and some research suggests statins may help prevent them.
Previous observational studies have suggested a relationship between Alzheimer's and gastrointestinal tract disorders.
But the team of Australian researchers said their new work has gone a step further, confirming a genetic link and identifying genes in common for individuals with Alzheimer's and multiple gut disorders.
"This improves our understanding of the causes of these conditions and identifies new targets to investigate to potentially detect the disease earlier and develop new treatments for both types of conditions," Emmanuel Adewuyi, the study's lead researcher and postdoctoral research fellow at the university, said in a news release.
Adewuyi describes the new study as "the first comprehensive assessment of the genetic relationship" between Alzheimer's disease and multiple gut disorders.
Scientists said the findings provide further evidence to support the concept of the 'gut-brain' connection, but stop short of showing GI diseases cause Alzheimer's or vice versa.
According to the news release, the Australian university's Centre for Precision Health analyzed large sets of genetic data from Alzheimer's and several gut-disorder studies -- each comprising about 400,000 people.
Upon further analysis into the shared genetics, the researchers found other important links between Alzheimer's disease and gut disorders, including the role that cholesterol may play.
"Looking at the genetic and biological characteristics common to [Alzheimer's] and these gut disorders suggests a strong role for lipids metabolism, the immune system, and cholesterol-lowering medications," Adewuyi said.
While further study is needed into the shared mechanisms between the diseases, there is evidence that high cholesterol can transfer into the central nervous system, resulting in abnormal cholesterol metabolism in the brain, he said.
And elevated cholesterol in the brain has been linked to brain degeneration and subsequent cognitive impairment, he added.
He also cited evidence suggesting that "abnormal blood lipids may be caused or made worse by gut bacteria, H. pylori, all of which support the potential roles of abnormal lipids in [Alzheimer's] and gut disorders."
Separately, scientists at Rutgers University released a study Monday that they said shows more evidence of how destructive tau proteins linked to Alzheimer's disease attack human brain cells. They focused on what happened to specialized immune brain cells known as microglia after these cells were exposed to tau proteins.
The Rutgers research on Alzheimer's disease was published in the journal Cell Stem Cell. said