Microorganisms Are Being Studied To Treat Alzheimer's — Here's What We Know So Far
Perhaps it's no surprise, then, that the microorganisms in probiotics are being investigated as a potential treatment for Alzheimer's disease (AD). A recently published systematic review2 of 22 studies gives us a bird's-eye view of the progress researchers have made in this area so far.
The research at a glance.
In his review, nutrition and intestinal health specialist Ben Witteman, M.D., looked into a handful of recent studies that researched the connection between gut health and cognitive decline, as well as the effect of probiotics on AD in clinical trials. After analyzing both human and animal studies, he summarized several key findings:
- A handful of human studies show promising results regarding probiotics for AD. Treatment using probiotics for at least four weeks consistently showed significant effects on cognitive function.
- Science shows us that an unhealthy gut likely promotes disease. An unhealthy makeup of gut bacteria increases gut permeability, likely disrupting the gut-brain axis. This leaves the gut vulnerable to inflammation and disease.
- Probiotics have an effect, but exactly how they affect the gut is not yet fully understood. Studies have repeatedly demonstrated the positive effects of probiotics on the body and mind. Researchers have theorized about the possible mechanisms behind the way probiotics work in the body, but we're still a long way off from anything definitive.
- Some studies have their limits. Witteman notes that some studies included in the review rely on psychological questionnaires rather than neuropsychological testing—which means there could be some bias—so any conclusions drawn will need further validation.
"I think the results of the different studies encourage the baseline thought that the gut microbiota is of importance not only for physical health but also for mental health (via the gut-brain axis)," Witteman tells mindbodygreen.
While it's exciting to see probiotics being used and tested against severe conditions like AD, science still has a ways to go when it comes to validating these early findings. There's an interesting path ahead, as research has yet to meaningfully examine related factors like the effect of prebiotics on AD.
Plus, it's always encouraging to have studies reconfirm the idea that supporting a healthy gut promotes our body's ability to prevent and fight disease, which functional and integrative medicine doctors have been asserting for decades.
"An interdisciplinary approach to investigate the interactions between host and microbiota could potentially lead to a strategic advance in treatment and prevention of AD in future," writes Witteman.
The research on the benefits of probiotics for diseases like AD is still emerging, but there are plenty of reasons to consider probiotics as a key part of your health tool kit right now.
How to support your second brain.
Not all probiotic supplements are created equal. Choosing a high-quality probiotic vetted by experts will ensure you're getting the most bang for your gut (and spending your hard-earned money on something that actually works). Here are nine clean, effective probiotics to look into.
A review of the most relevant recent studies on the use of probiotics to support cognitive health gives us reason to be very optimistic. Additional research and collaboration across disciplines are promising next steps for this topic.
Jenny is a San Francisco-based mbg health contributor, content designer, and climate & sustainability communications specialist. She is a graduate of the University of California Santa Barbara. An avid open-water swimmer, Jenny has worked for healthy living and nutrition brands like Sun Basket, Gather Around Nutrition, and Territory Foods.