Looking for links between diet, gut microbes and cognitive decline

May 11, 2018 by Nancy Difiore, Rush University Medical Center
Credit: Rush University Medical Center

Are abnormal intestinal microorganisms a risk factor for developing cognitive impairment? Researchers at Rush University Medical Center are trying to answer that question with a new, National Institute on Aging-funded study that will explore how the intestinal microbiota—the bacteria in the intestine—influence the progression of cognitive decline and the development of Alzheimer's disease.

Health care providers and researchers increasing are recognizing that the intestinal microbiota—also known as the microbiome—affects health. The human intestine contains tens of trillions of microorganisms, and humans have developed a symbiotic relationship with these bacteria in.

Food consumption by humans provides food/energy to this , which in turn influence health by producing numerous biologically relevant substances, including vitamins, and strongly influence the immune system. Studies show that the intestinal microbiota also influences the .

For example, changes in the intestinal microbiota can influence anxiety- and depression-like symptoms in rodents and can promote brain pathology in a mouse model of Parkinson's disease.

"Diet is one of the main factors that influence the intestinal microbiota," said Dr. Robin Voigt-Zuwala, an assistant professor in the Department of Internal Medicine at Rush who is leading the study. "Therefore, a dietary intervention provides a perfect platform to study how alterations in the intestinal microbiome influence the aging brain, cognition, and Alzheimer's disease development."

The study will recruit 300 volunteers from another study, the Chicago MIND cohort, which aims to show whether a dietary intervention can prevent cognitive decline and age-associated changes in the brain. The MIND is short for Mediterranean-DASH Diet Intervention for Neurodegenerative Delay, which is a hybrid of the Mediterranean and DASH (Dietary Approaches to Stop Hypertension) diets.

Martha Clare Morris, ScD, a Rush nutritional epidemiologist, and her colleagues developed the MIND diet based on information that has accrued from years of research about what foods and nutrients have good, and bad, effects on the functioning of the brain. "We are expanding on the goals of the MIND diet trial to mechanistically investigate if and how the microbiome influences the aging brain," said Voigt-Zuwala.

"The proposed research is significant because it will, for the first time, provide a mechanistic understanding of how the microbiome contributes to preclinical Alzheimer's disease. This is expected to pave the way for intestine-directed treatments to prevent or delay cognitive decline, such as the MIND diet."

Healthier microbiome may protect the brain

Alzheimer's disease is the most common cause of dementia, currently afflicting an estimated 5.7 million people in the United States, and has the highest drug/treatment failure rate of any disease. There is a substantial body of literature suggesting that a healthy diet is beneficial for Alzheimer's disease prevention.

This study will be the first that seeks to provide evidence pointing to diet-induced effects on the microbiome as a critical factor that age-associated cognitive decline and the development of Alzheimer's disease.

The researchers will put the study participants onto the MIND diet or a control diet for three years, and they will collect cognitive and biological data from participants every year. Participants also will provide specimens that the researchers will use to assess the intestinal microbiota with state-of-the-art techniques.

They will evaluate what bacteria are present (the bacterial community structure) and the organisms' function, providing critical information about what bacteria are present and what they are doing. These outcomes will be correlated with cognitive outcomes and brain structure information obtained via MRI exams. A better mechanistic understanding will be revealed by examining changes in other intestinal outcomes such as "leaky gut" and changes in the immune system.

"One of the biggest challenges facing Alzheimer's disease is that the disease process begins more than a decade before the onset of clinically detectable symptoms. Thus, intervention trials targeted at the preclinical stages of neurodegenerative are necessary," Voigt-Zuwala said. "This study is an important stepping stone towards understanding the role of the intestine in age-associated and paves the way for the development of intestine-directed treatments to improve quality of life in older populations."

Explore further: First study of diet's impact on dementia, Alzheimer's disease begins in January

Related Stories

First study of diet's impact on dementia, Alzheimer's disease begins in January

January 4, 2017
The first study of its kind designed to test the effects of a diet on the decline of cognitive abilities among a large group of individuals 65 to 84 years who currently do not have cognitive impairment will begin in January.

MIND diet may slow cognitive decline in stroke survivors

January 25, 2018
A diet created by researchers at Rush University Medical Center may help substantially slow cognitive decline in stroke survivors, according to preliminary research presented on Jan. 25, at the American Stroke Association's ...

AAIC: Mediterranean diet may help preserve cognitive function

July 18, 2017
(HealthDay)—Eating right may help protect brain health in old age, a group of new studies show. The research was scheduled for presentation at the annual Alzheimer's Association International Conference, held from July ...

Gut bacteria may play a role in Alzheimer's disease

February 10, 2017
New research from Lund University in Sweden has shown that intestinal bacteria can accelerate the development of Alzheimer's disease. According to the researchers behind the study, the results open up the door to new opportunities ...

Eating away at cognitive decline: MIND diet may slow brain from aging by 7.5 years

August 4, 2015
While cognitive abilities naturally diminish as part of the normal aging process, it may be possible to take a bite out of this expected decline.

Diet proven to lower the risk of Alzheimer's disease also ranked No. 1 easiest to follow

January 5, 2016
A diet created, studied and reported on by researchers at Rush University Medical Center has been ranked the easiest diet to follow and the second best overall diet (tying in both categories) for 2016 by U.S. News & World ...

Recommended for you

New blood test to detect liver damage in under an hour

May 24, 2018
A quick and robust blood test that can detect liver damage before symptoms appear has been designed and verified using clinical samples by a team from UCL and University of Massachusetts.

Selective neural connections can be reestablished in retina after injury, study finds

May 24, 2018
The brain's ability to form new neural connections, called neuroplasticity, is crucial to recovery from some types of brain injury, but this process is hard to study and remains poorly understood. A new study of neural circuit ...

Space-like gravity weakens biochemical signals in muscle formation

May 23, 2018
Astronauts go through many physiological changes during their time in spaceflight, including lower muscle mass and slower muscle development. Similar symptoms can occur in the muscles of people on Earth's surface, too. In ...

Eating at night, sleeping by day swiftly alters key blood proteins

May 21, 2018
Staying awake all night and sleeping all day for just a few days can disrupt levels and time of day patterns of more than 100 proteins in the blood, including those that influence blood sugar, energy metabolism, and immune ...

Hotter bodies fight infections and tumours better—researchers show how

May 21, 2018
The hotter our body temperature, the more our bodies speed up a key defence system that fights against tumours, wounds or infections, new research by a multidisciplinary team of mathematicians and biologists from the Universities ...

Deep space radiation treatment reboots brain's immune system

May 21, 2018
Planning a trip to Mars? You'll want to remember your anti-radiation pills.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.