Gut health can affect the likelihood of developing

Could changing your diet play a role in slowing or even preventing the development of dementia? We’re one step closer to finding out, thanks to a new UNLV study that supports a long suspected link between gut health and Alzheimer’s disease.

Analysis – led by a research team with the Nevada Institute of Personalized Medicine (NIPM) at UNLV and published this spring in the journal Nature Scientific Reports – examines data from dozens of previous studies on the gut-brain connection. Results? There is a strong link between certain types of gut bacteria and Alzheimer’s disease.

Between 500 and 1,000 species of bacteria exist in the human gut at any one time, and the number and diversity of these microorganisms can be influenced by genetics and diet.

The UNLV team’s analysis found a significant correlation between 10 specific types of gut bacteria and the likelihood of developing Alzheimer’s disease. Six categories of bacteria — Adlercreutzia, Eubacterium nodetum group, Eisenbergiella, Eubacterium fissicatena group, Gordonibacter, And Prevotella9 — identified as protective, and four types of bacteria — Collinsella, Bacteroides, Lachnospira, And Veillonella – identified as a risk factor for Alzheimer’s disease.

Certain bacteria in the human gut can secrete acids and toxins that thin and permeate through the intestinal lining, interacting with APOE (a gene identified as a major risk factor for Alzheimer’s disease), and triggers a neuroinflammatory response — affecting brain health and various immune functions, and potentially driving the development of neurodegenerative disorders.

The researchers say their new discovery of a different group of bacteria associated with Alzheimer’s disease provides new insight into the relationship between the gut microbiota and the world’s most common form of dementia. The findings also advance scientists’ understanding of how such bacterial imbalances may play a role in the development of the disorder.

“Most of the microorganisms in our gut are considered health-promoting good bacteria, but an imbalance of these bacteria can be toxic to a person’s immune system and linked to various diseases, such as depression, heart disease, cancer, and Alzheimer’s disease,” said the UNLV research professor. Jing Chun Chen. “The take home message here is that your genes not only determine whether you are at risk for disease, they can influence the abundance of bacteria in your gut.”

While their analysis established the category of bacteria typically associated with Alzheimer’s disease, the UNLV team said further research is needed to explore the specific bacterial species that influence risk or protection.

The hope is to one day develop treatments tailored to individual patients and their genetic makeup, such as medication or lifestyle changes. Studies have shown that changing the gut microbiome through the use of probiotics and dietary adjustments can positively impact the immune system, inflammation and even brain function.

“With more research, it will be possible to identify genetic pathways that could lead to a gut microbiome that will be more or less susceptible to diseases such as Alzheimer’s,” said lead author of the study and UNLV graduate student Davis Cammann, “but we must also remember that the gut biome influenced by many factors including lifestyle and diet.”

Publication Details

“Genetic correlation between Alzheimer’s disease and gut microbiome genera” published this spring Scientific Reports.

In addition to faculty researchers, undergraduate, and graduate students from NIPM, scientists from UNLV College of Science, UNLV School of Dentistry, UNLV School of Integrated Health Sciences Department of Brain Health, Kirk Kerkorian School of Medicine at UNLV, Columbia University, and University Health Sciences Center Texas in Houston contributed to this research.