Everything we eat drink, and consume is processed through the gut microbiome a complex ecosystem of trillions of microorganisms including bacteria, fungi, parasites, and viruses. These microbes play a crucial role in digestion immune function and even brain health.

Emerging research suggests the gut significantly influences neurological health and may affect the progression of neurodegenerative diseases like Alzheimer’s.

At the Indiana University School of Medicine Dr. Miguel Moutinho, assistant research professor of anatomy, cell biology, and physiology, is exploring how gut bacteria influence microglial activity in Alzheimer’s disease. His work is supported by a three-year \$300,000 grant from the BrightFocus Foundation.

In earlier studies Dr. Moutinho discovered that niacin a B vitamin essential for energy production interacts with a specific brain immune cell receptor known as HCAR2. When Alzheimer’s disease models were treated with an FDA-approved niacin formulation commonly used to lower cholesterol the receptor was activated resulting in reduced plaque buildup and improved cognitive function.

Building on his previous findings Moutinho is now exploring the link between niacin balance (homeostasis) and the gut microbiome in Alzheimer’s disease. Research has shown that individuals with Alzheimer’s often exhibit a disrupted gut microbiome compared to those without the condition. This imbalance in gut bacteria may contribute to chronic inflammation and negatively impact the gut-brain connection.

Our lifestyle directly affects the gut microbiota said Needham. Eating healthy not only supports our overall well-being but also nurtures the microbial community in our gut. If we neglect this balance through poor dietary or drug choices it can lead to an increase in harmful compounds in the body.

According to Moutinho certain gut bacteria naturally produce niacin a vitamin essential for brain health as well as the regulation of blood sugar metabolism and cholesterol. In Alzheimer’s disease the pathway involved in gut-based niacin production may become disrupted potentially leading to a deficiency.

A reduced supply of niacin to the brain can impair activation of the HCAR2 receptor in microglia the brain’s immune cells which may contribute to Alzheimer’s progression Moutinho explained.

His research team is now examining whether gut bacteria that produce niacin can directly influence Alzheimer’s pathology. Using animal models they aim to manipulate a specific bacterial pathway involved in niacin production to determine if boosting niacin biosynthesis in the gut can alter the course of the disease.

The Stark Neurosciences Research Institute hosts one of IU School of Medicine’s largest PhD programs training over 40 students. First-year PhD student Daniella Lopes, who completed her undergrad at IU Indianapolis, is now working with Moutinho and Needham on the gut microbiome project. Initially rotating in Needham’s lab, she later joined Moutinho’s team to explore the gut-brain axis. I’ve never worked with microbiology so combining it with neurodegeneration research felt like the perfect opportunity Lopes said.

Source: https://medicine.iu.edu/blogs/neuroscience/gut-bacteria-impacting-alzheimers