How a Healthy Gut Relates to a Healthy Brain

Q. I heard that there’s a strong link between particular kinds of gut bacteria and Alzheimer’s disease. Is this true, and if so, how do I know if my gut is, in fact, healthy? If not, what changes can I make to improve it, and perhaps reduce my chance of developing dementia? Thanks for your help!

A. Over the past few years, there has been a lot of research that suggests how the health of a person’s gut can affect their overall health. It has been found that a well-balanced gut microbiome may help ward off diseases such as inflammatory bowel disease, Crohn’s disease, and ulcerative colitis. Recently, at the 2023 Alzheimer’s Association International Conference (AAIC 2023), a correlation between gut health and Alzheimer’s disease and other types of dementia was discussed. Researchers from the University of Nevada, Las Vegas (UNLV) have identified 10 specific types of bacteria in the gut associated with the likelihood of developing Alzheimer’s disease and presented this research to their peers at AAIC 2023.

The Gut-Brain Connection in Alzheimer’s

Most people are surprised that their gut bacteria could affect their mood, their behaviors, and brain functions, but the evidence is mounting, and researchers are building an understanding of how gut bacteria and the health of the brain are connected. The UNLV study, published in the journal Scientific Reports, examined data from dozens of past studies into the gut-brain connection. Here are some of the findings:

• Changes in gut bacteria can affect the immune system, leading to chronic inflammation throughout the body, including the brain. This inflammation is thought to play a role in the development of various neurodegenerative diseases, including Alzheimer’s disease.
• Most of the microorganisms in our intestines are considered to be good bacteria that promote health, but an imbalance of those 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. According to Dr. Jingchun Chen, lead scientist on this study at UNLV, “In general, when the balance of gut bacteria is disrupted, it can lead to inflammation and immune dysfunction in the gut and throughout the body. This, in turn, can contribute to chronic inflammation in the brain, which is a hallmark of Alzheimer’s disease.”
• Research found a significant correlation between 10 specific types of gut bacteria and the likelihood of developing Alzheimer’s disease.
  • Six categories of bacteria were identified as protective.
  • Four types of bacteria were identified as a risk factor for Alzheimer’s disease. This is because these bacteria secrete acids and toxins that seep through the intestinal lining, interact with the APOE (a gene identified as a major risk factor for Alzheimer’s disease), and trigger a neuroinflammatory response — affecting brain health and numerous immune functions and potentially promote development of the neurodegenerative disorder.
• The UNLV team said that more research is needed to further drill down into the specific bacterial species that influence risk or protection.
• Your genes not only determine whether you have a risk for a disease, but they can also influence the abundance of bacteria in your gut.
  • The hope is to one day develop treatments that are customized for an individual patient and their genetic makeup, such as medications or lifestyle changes.
• This identification of a potential link between gut bacteria and Alzheimer’s disease has opened up new avenues for research into the prevention and treatment of this devastating disease.
  • According to Dr. Chen, “If researchers can understand the mechanisms by which gut bacteria contribute to the development of Alzheimer’s disease, it may be possible to develop new therapies that target these mechanisms.”

Dr. Chen said these findings can be used by doctors in the future to highlight the importance of maintaining a healthy gut microbiome for overall health and well-being, including brain health. “By educating patients about the importance of maintaining a healthy gut microbiome, doctors may be able to help prevent or delay the onset of Alzheimer’s disease and other neurodegenerative conditions,” she added.

How Do You Know if Your Gut Microbiome Is Healthy?

The gut microbiome consists of trillions of microscopic organisms living in the body’s intestinal tract. These microorganisms assist with nutrient absorption from food, breaking down fiber, recovering energy from food metabolism, and keeping the gut safe from diseases.

Every person’s gut microbiome is different. What is in it depends on a person’s diet, genetics, medication, and surrounding environment. Signs of an unhealthy gut microbiome can include gas and/or bloating, constipation, diarrhea, heartburn, fatigue, trouble sleeping, food intolerance, unintentional weight loss or gain, skin issues, sugar cravings, and mood changes, including anxiety and depression.

Thankfully, there are a number of ways you can improve your gut microbiome, including:
eating a diverse diet, including:

• prebiotic food;
• exercising regularly;
• eating fermented foods;
• taking probiotic supplements;
• eating less sugar and artificial sweeteners;
• getting a good amount of sleep;
• not smoking; and
• avoiding antibiotics when not needed.

According to UNLV scientists, “(g)ut biome is influenced by many factors including lifestyle and diet. Studies have shown that changes in gut microbiome through probiotic use and dietary adjustments can positively impact the immune system, inflammation, and even brain function.”

Further Research and Treatment Opportunities

“Our body systems are all interconnected,” said Heather M. Snyder, Ph.D., Alzheimer’s Association vice president of medical and scientific relations. “When one system is malfunctioning, it impacts other systems. When that dysfunction isn’t addressed, it can create a waterfall of consequences for the rest of the body.”

This is why, to study the gut-brain relationship further, the Alzheimer’s Association is spearheading the U.S. Study to Protect Brain Health Through Lifestyle Intervention to Reduce Risk, with support from the US National Institutes of Health. The study is examining the impact of behavioral interventions on the gut-brain axis to better understand how engaging in healthier habits impacts microorganisms in the gut and how changes in gut bacteria relate to brain health.

Dr. David Merrill, a geriatric psychiatrist in Santa Monica, CA, agrees, “(w)e now know that dementia risk can be modified through changes in diet and lifestyle-related behaviors, so it would make sense to target those lifestyle changes in a way that helps promote a healthy gut microbiome,” he explained. “If we learn what constitutes a lower dementia risk microbiome, then we might try to target achieving that gut microbiome makeup in an effort to actually decrease dementia risk.” Dr. Merrill believes that in a nutshell, “(I)f your general health is good, your brain health should be better, too!”

Are You Experiencing Memory Problems?

Many people worry that memory problems are related to early Alzheimer’s disease or another form of dementia. However, some problems are normal and just related to aging, and do not signify dementia. Normal age-related changes often cause minor difficulties with immediate memory. As described, a change in diet and adopting some other healthy habits that affect your gut biome can be beneficial to your health and may lower your risk of Alzheimer’s or other forms of dementia. If you are experiencing memory loss that affects your day-to-day living, be sure to see your doctor to be tested for dementia so you can plan as early as possible.

People with Dementia and Their Families Should Plan for the Future As Soon As Possible

People with dementia and their families face special legal and financial needs. At the Farr Law Firm, we are dedicated to easing the financial and emotional burden on those with dementia and their loved ones. We help protect the family’s hard-earned assets while maintaining your loved one’s comfort, dignity, and quality of life by ensuring eligibility for critical government benefits. If someone in your family has been diagnosed with dementia, please call us as soon as possible to make an appointment:

Northern Virginia Elder Law Attorney: 703-691-1888
Fredericksburg, VA Elder Law Attorney: 540-479-1435
Rockville, MD Elder Law Attorney: 301-519-8041
Annapolis, MD Elder Law Attorney: 410-216-0703
DC Elder Law: 202-587-2797