Jessica Caldwell, PhD is the director of the Women’s Alzheimer’s Movement Prevention and Research Center. She spoke with us about gut health and the gut-brain connection.
Read the Q&A with Dr. Caldwell below.
WAM: How might the tiny bacteria living in our gut affect brain health and memory loss as we get older?
Dr. Caldwell: I think it’s most helpful to remember that the gut and the brain are not living in separate worlds. The public tends to think about Alzheimer’s disease as a brain disease, but we know now that the gut and the brain are interconnected. In the gut we have what’s called the microbiome, a collection of all the genomes of what lives in our gut. Bacteria or viruses or fungi and all that microbiome is important for maintaining a healthy blood-brain barrier. It’s important not just for our bodily health, our heart health, but also for our brain function. Many people don’t really think about it, but the products of that microbiome include even things like neurotransmitters or signaling molecules. When we don’t have the right complement of signaling molecules and healthy products, we wind up with not only, a not very well functioning gut, but also can be at risk for brain changes.
WAM: Does the variety of bacteria in our digestive system have any connection to how well our brain works as we age?
Dr. Caldwell: This is an active area of research. Studies have shown that particular types of gut bacteria variety are good for digestive health, for example, and now researchers have had a focus on impact for the brain.
WAM: Is there a connection between a leaky gut, body-wide inflammation, and the build-up of harmful proteins in the brain?
Dr. Caldwell: Inflammation can impact the brain, especially the type of inflammation that is chronic and unrelenting. This type of inflammation is the type that can be caused by a pro-inflammatory diet. One that doesn’t have as many good prebiotic, probiotic, whole food and fiber. Instead, it includes a lot of processed foods, red meat and whole fat dairy products, all of which can cause low-level inflammation that’s chronic. When there’s chronic inflammation throughout the body, it can induce brain-based inflammation; the type that should be avoided to keep our brain healthy.
WAM: Could changing what we eat help protect our brain and reduce the risk of memory problems?
Dr. Caldwell: There are lots of things we can do to support a more healthy and less inflammatory stomach and gut-based profile. Things like avoiding processed foods, having a diet rich in plant-based dietary fiber and whole foods that support heart health and the complement of products that your gut would need in order to do what it does for the brain. A diet, like the Mediterranean or MIND diets, which emphasizes whole foods, healthy fats and leafy greens for a plant-based dietary fiber really supports brain health as well as gut health and heart health.
WAM: Could taking special probiotics or supplements help prevent memory loss and brain diseases?
Dr. Caldwell: I like to remind patients who ask about the microbiome and supplements that it isn’t that simple. There are good things that you can put into the microbiome and there are bad things you want to take out. Most of the time no single prebiotic, which would help your microbiome grow the right kind of bacteria, or probiotic, that helps the bacteria thrive, or post, bacteria made naturally in the gut, can do it all. Meaning a single supplement is unlikely to be the answer to totally revamping gut health.