The results of a recent study published in the journal “Science Translational Medicine” (Wednesday) show that people in the early stages of Alzheimer’s disease — when changes in the brain begin to occur and before symptoms of the disease appear — harbor a variety of bacteria that differ from the bacteria in the guts of healthy people.

In this early stage of Alzheimer’s disease, people with clumps of amyloid-beta and tau proteins build up in their brains, a condition that persists for two decades or more, although patients show no signs of neurodegeneration or cognitive decline. According to the findings of a study conducted by researchers at Washington University School of Medicine in St. Louis, no one has ever looked at the gut microbiome in the pre-symptomatic stage.

“A change in the gut microbiome can read pathological changes in the brain,” study co-author Gautham Dantas, a professor of genetic medicine at the university and an expert on the gut microbiome, said in a press release Wednesday.

He added, “Other altered gut microbiota may be a contributor to Alzheimer’s disease, including through probiotics (a beneficial diet) or stool replacement (with the beneficial bacteria it carries). The disease.”

The results open up the possibility of using gut bacteria analysis to identify people at risk of developing Alzheimer’s disease at a very early stage, and thus design preventative treatments to alter the microbiome to reduce the risk of developing the disease. A key feature of dementia and cognitive decline.

“With the onset of cognitive symptoms, there are important and often irreversible changes,” said Poe M. Anis said: “If you can diagnose a patient early in the disease, this is the time.” Ideal for effective therapeutic intervention.

The researchers evaluated the participants, all of whom were cognitively normal. Participants were given stool, blood, and cerebrospinal fluid samples and food lists; They also performed positron emission tomography and magnetic resonance imaging (MRI) scans of the brain.

The researchers examined signs of accumulation of amyloid-beta and tau proteins to differentiate participants from healthy individuals in the early stages of the disease. Of the 164 participants, nearly a third (49) had early symptoms of the disease.

Early in life, people with Alzheimer’s disease develop gut bacteria that are significantly different from their healthy counterparts, both in terms of the types of bacteria and the biological processes they are involved in. The study’s authors say these differences could be used to detect early Alzheimer’s disease.

For his part, Dr. Walid Mahmoud Al-Sharoud, Professor of Microbial Physiology and Food Safety at Mansoura University in Egypt, said in a statement to Asharq Al-Awsat: “The results show a correlation between the quality of the gut microbiome and the initial conditions. Alzheimer’s disease, in which mental disorders do not appear, but rather changes in the amount of amyloid and tau proteins in brain cells and tissues, is a phase that follows the mental changes associated with Alzheimer’s disease. Up to twenty years.

According to the study, these differences are associated with levels of amyloid and tau proteins, which rise before cognitive symptoms appear, but are not associated with neurodegeneration, whose symptoms also begin to appear over time.

“The beauty of using the gut microbiome as a screening tool is its simplicity and ease of use,” says Anis: “People can one day provide a stool sample and find out if they’re at risk of developing Alzheimer’s.”

Al-Sharoud believes, “The results of the study are interesting and confirm the relationship between gut microbiota and human health.”

Looking ahead, the researchers launched another five-year follow-up study to determine whether differences in the gut microbiome are a cause or a consequence of the brain changes seen in early Alzheimer’s disease.

“If there is a causal link, it could be an inflammatory link,” explains Dantas, “Bacteria are amazing chemical factories, and some of their metabolites affect inflammation in the gut, and they can reach the bloodstream. Affect the body’s immune system.” , if it turns out that there is a causal relationship, we can start thinking about whether increasing the ‘good’ bacteria or eliminating the ‘bad’ bacteria could slow or stop the progression of Alzheimer’s symptoms.