Gut Check

“You are what you eat” is not just a catchy saying. Medical science is discovering more and more links between bacteria in the digestive tract — the gut microbiome — and physical and mental health. 

“It’s amazing when you think of the gut microbiome — made up of trillions of tiny bacteria — supporting the digestive and immune systems and brain functioning,” said Laura Umfleet, PsyD, neuropsychologist and Medical College of Wisconsin faculty member. 

Exploring the Gut-Brain Connection in Alzheimer’s Research

Umfleet leads a team exploring potential links between gut and oral microbiomes and Alzheimer’s disease. The team includes MCW faculty members Malgorzata Franczak, MD, neurologist and director of the Memory Disorders Program; John Kirby, PhD, chair of microbiology and immunology; and Yang Wang, MD, radiologist. 

Alzheimer’s disease has been studied for decades, but effective treatment remains elusive. This new research looks at people with different levels of brain health, from normal aging to early signs and symptoms of dementia. 

Who Can Participate in the Microbiome and Brain Study?

It includes adults ages 50 and older — some with no memory issues; some with mild memory and other cognitive concerns; and others diagnosed with mild cognitive impairment, an early stage of dementia. The team is conducting two distinct projects funded by the National Institute on Aging, the Daniel M. Soref Charitable Trust, and the Elizabeth T. and James B. Wigdale Innovation Fund for Memory Disorders. 

Connecting the Gut, Mouth, and Brain for Early Detection

“These studies are alike in that they both explore the connection between the gut and the brain, but they focus on different clinical groups,” Umfleet said. “One study goes beyond the gut to look at the oral microbiome and other biological markers. We’re connecting different parts of the body — like the gut and mouth — to brain health, which could lead to more accurate early detection tools and better treatments for Alzheimer’s disease.” 

What Study Participants Can Expect

Participants are asked to complete two study visits. This first visit includes cognitive testing of memory and other thinking skills, questionnaires and collection of saliva and blood samples. Participants are sent home with a stool collection kit and mailing materials. The second visit is an MRI brain scan to look for structural changes and examine vascular function. As the study expands, it is anticipated that participants will return yearly for analysis of their microbiome and changes in brain functioning. 

A New Era in Alzheimer’s Prevention and Treatment

“Historically, Alzheimer’s disease research focused on the dementia stage, when it’s too late to intervene,” Umfleet said. “There has been a critical shift toward identifying and treating the disease earlier. If researchers learn how to tease apart and understand microbiome changes and potential treatment targets, it will benefit patients, families and society. When we truly know how the gut-brain axis functions, we may be able to prevent Alzheimer’s disease from getting worse — or hopefully prevent it altogether.”