Gut bacteria tied to odds of getting Alzheimer’s

Could a tweak to your grub be a way to slow down, or even stop, dementia in its tracks? We’re getting closer to finding out, thanks to a new study from the University of Nevada, Las Vegas (UNLV) that strengthens the suspected link between gut health and Alzheimer’s disease.

This research, led by a team from the Nevada Institute of Personalized Medicine (NIPM) at UNLV and featured in the Nature journal Scientific Reports, looked at data from loads of past studies on the connection between your belly and your brain. What did they find? There’s a solid link between certain types of gut bacteria and Alzheimer’s disease.

Anywhere from 500 to 1,000 types of bacteria can be found in the human gut at any given time, and the number and variety of these tiny creatures can be swayed by your genes and your diet.

The UNLV team’s investigation found a big link between ten particular types of gut bacteria and the chances of getting Alzheimer’s disease. Six types of bacteria — Adlercreutzia, Eubacterium nodatum group, Eisenbergiella, Eubacterium fissicatena group, Gordonibacter, and Prevotella9 — were identified as good guys, while four types — Collinsella, Bacteroides, Lachnospira, and Veillonella — were flagged as likely to increase your risk of Alzheimer’s.

Certain bacteria in our guts can produce acids and toxins that can damage the lining of the gut, mess with the APOE (a gene we know is a big risk factor for Alzheimer’s), and set off an inflammatory response in the brain. This could have a knock-on effect on brain health and various immune functions, and could encourage the development of Alzheimer’s.

The researchers reckon their new discovery of the specific bacterial groups linked to Alzheimer’s disease gives us fresh insight into the relationship between gut bacteria and the most common type of dementia. The findings also improve our understanding of how an imbalance of that bacteria could play a part in the disease.

“Most of the microorganisms in our intestines are considered good bacteria that promote health, but an imbalance of those bacteria can be harmful to a person’s immune system and linked to various diseases, such as depression, heart disease, cancer, and Alzheimer’s disease,” UNLV research professor Jingchun Chen commented. “The key point here is that your genes don’t just determine whether you’re at risk of a disease, but they can also influence the amount of bacteria in your gut.”

While their investigation established general categories of bacteria typically linked with Alzheimer’s, the UNLV team reckon more research is needed to identify the specific bacterial species that influence risk or protection.

The hope is that one day we could develop treatments that are tailored to an individual patient and their genetic makeup, like medications or changes to lifestyle. Studies have shown that changes to the gut microbiome through probiotics and diet can have a positive effect on the immune system, inflammation, and even brain function.

“With more research it would be possible to identify a genetic pattern that could point to a gut microbiome that would be more or less likely to develop diseases such as Alzheimer’s,” said Davis Cammann, the study’s lead author and a UNLV graduate student. “But we also have to remember that the gut biome is influenced by many factors including lifestyle and diet.”

The study, titled “Genetic correlations between Alzheimer’s disease and gut microbiome genera,” also saw contributions from faculty, undergraduate, and graduate student researchers from NIPM, as well as scientists from the UNLV College of Sciences, UNLV School of Dental Medicine, UNLV School of Integrated Health Sciences’ Department of Brain Health, Kirk Kerkorian School of Medicine at UNLV, Columbia University, and the University of Texas Health Science Center at Houston.

So, what does all this mean? Simply put, the food we eat might not just be about keeping our bodies in good nick, but also about keeping our minds sharp.

The details of the findings are a bit complex, but the overall message is clear as day: diet, previously just seen as a means of keeping our bodies healthy, could also be key to our mental health.

While the study doesn’t give us a straightforward recipe to follow — not just yet anyway — it does give us a glimpse of what future medical advances might look like, and the potential for a time when dementia isn’t a given, but something we can prevent. It paints a picture of a future where your shopping list could double up as a prescription for good health.

The researchers at UNLV and their collaborators are starting to untangle the complicated relationship between our bellies and our brains, a relationship that’s affected by both our genes and our choices. As they continue to dig into this complex interplay, we might find that what we choose to eat can have a big impact on our mental health.

The human body still holds plenty of mysteries, but this study shines a light into the dark corners of Alzheimer’s research. As we move into the future, the next meal we eat could be a key part of keeping us healthy and full of life.

The material in this press release comes from the originating research organization. Content may be edited for style and length. Want more? Sign up for our daily email.