Scientists discover a big contributor of Alzheimer’s disease starts from the gut

Credit: CC0 Public Domain

Scientists from Louisiana State University found for the first time a pathway that begins in the gut and ends with a potent pro-inflammatory toxin in brain cells contributing to the development of Alzheimer’s disease (AD).

They also report a simple way to prevent it.

In the study, the team found evidence that a molecule containing a very potent microbial-generated neurotoxin (lipopolysaccharide or LPS) derived from the Gram-negative bacteria Bacteroides fragilis in the human gastrointestinal (GI) tract generates a neurotoxin known as BF-LPS.

Many studies have detected different forms of LPS within neurons of the Alzheimer’s disease-affected human brain.

In this study, the researchers detail the pathway of BF-LPS from the gut to the brain and its mechanisms of action once there.

BF-LPS leaks out of the GI tract, crosses the blood-brain barrier via the circulatory system and accesses brain compartments.

Then it increases inflammation in brain cells and inhibits neuron-specific neurofilament light (NF-L,) a protein that supports cell integrity.

A deficit of this protein leads to progressive neuronal cell atrophy, and ultimately cell death, as is observed in AD-affected neurons. They also report that adequate intake of dietary fiber can head off the process.

The novel features of this newly described pathological pathway are threefold. The AD-stimulating pathway begins inside of us—in our GI-tract microbiome—and therefore is very “locally sourced” and active throughout our lives.

The highly potent neurotoxin BF-LPS is a natural by-product of GI-tract-based microbial metabolism.

Bacteroides fragilis abundance in the microbiome, which is the source of the neurotoxin BF-LPS, can be regulated by dietary fiber intake.

The team says dietary-based approaches to balance the microorganisms in the gut microbiome may help modify the abundance, speciation, and complexity of enterotoxigenic forms of AD-relevant microbes.

It has been estimated that Americans eat 10–15 grams of fiber a day on average. The USDA recommends that women up to age 50 consume 25 grams a day and men 38 grams.

Over age 50, women and men should consume 21 and 30 grams daily, respectively.

If you care about Alzheimer’s disease, please read studies about a new way to prevent Alzheimer’s disease, and medical cannabis can reduce this brain disorder.

For more information about brain health, please see recent studies about 13 things your doctor can check to help protect brain health, and results showing new drug for Alzheimer’s disease prevention is safe and effective.

The research was published in Frontiers in Neurology and conducted by Drs. Yuhai Zhao et al.

Copyright © 2022 Knowridge Science Report. All rights reserved.