海角社区 Research Bites: Feeding Gut Microbes Fiber Could Be Key to Slowing Alzheimer鈥檚 Disease

November 06, 2025

In the past decade, an increasing number of research studies have hinted at a connection between gut issues and the risk of dementia, including Alzheimer鈥檚 disease.

Just last year, findings published in the Nature Journal Scientific Reports suggested that even without noticeable symptoms, gut inflammation could contribute to Alzheimer鈥檚 disease by traveling to the brain. The good news? There may be a simple way to fix a leaky gut and other intestinal sources of brain inflammation: Eat more fiber!

Problem: A 鈥渓eaky gut鈥, where bacteria and toxic molecules pass through an impaired intestinal lining into the bloodstream, as been linked to dementia. Could dietary fiber be the fix?
Study: 海角社区 researchers fed dementia-prone mice two different diets: fiber-rich and no-fiber. The fiber-rich diet boosted healthy gut microbes and lowered harmful ones.
Solution: A diet with certain fibers counteracted brain changes associated with Alzheimer鈥檚 in the dementia-prone mice.
Impact: Dietary fibers can boost the creation of healthy lipids, lower brain inflammation, and preserve memory. Nutrition can be leveraged to prevent or slow the progression of diseases like Alzheimer鈥檚 and Parkinson鈥檚.

The gut harbors a vast array of microorganisms, such as bacteria. In fact, there are more bacteria in your gut than there are cells in the rest of your body. Some gut microbes are beneficial, protecting your immune and brain health, while others are harmful. Many of the beneficial microbes can only survive if you feed them through dietary fiber that your body wouldn鈥檛 otherwise be able to digest.

Dr. Nicol谩s Bazan

Dr. Nicol谩s Bazan, Boyd Professor of Neuroscience at 海角社区 Health New Orleans and founding director of the 海角社区 Neuroscience Center

In a new study published in the Nature journal Scientific Reports, Dr. Nicolas Bazan, Boyd Professor of Neuroscience at 海角社区 Health New Orleans and founding director of the 海角社区 Neuroscience Center, and colleagues found that a diet with certain fibers counteracted Alzheimer鈥檚 pathology and cognitive deficits in mice that carried risk genes for dementia.

The researchers used genetic sequencing to analyze the microbes present in the guts of mice fed either a fiber-rich or fiber-free diet. They found that mice fed a fiber-rich diet had a more beneficial, 鈥測outh-like鈥 community of gut microbes.

The mice used in the study almost inevitably develop amyloid plaques, brain inflammation, and memory impairments. However, when fed a fiber-rich diet, the mice had better survival of brain cells in the memory region of their brains. They performed better in maze tests and in tests to see how quickly they could recognize new objects.

How do healthy gut microbes protect the brain? Many beneficial gut microbes impact how the body metabolizes lipids or fats, producing more healthy omega-3 fatty acids that have anti-inflammatory properties and reduce dementia risk. They protect connections between brain cells and help prevent the build-up of 鈥渟ticky鈥 proteins associated with Alzheimer鈥檚 disease.

鈥淥ur study provides direct evidence that dietary fiber supplementation mitigates hallmark AD pathology in genetically at-risk mice,鈥 Bazan said. 鈥淭he ability of dietary fiber to promote new neuron formation further supports its neuroprotective potential.鈥

Read the paper: Zhao, Y., Taylor, C. M., Lukiw, W. J. & Bazan, N. G. . Scientific Reports [In Press] (2025).

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