Preventing Alzheimer’s Disease With Gut Microbes

The connections we are discovering between the brain and the gut could point towards new treatment option for various brain diseases

What does the gut have to do with it?

When we talk about Alzheimer’s disease, we usually think about the brain. After all, the condition is associated with cognitive, memory, and behavioral problems. This progressive brain disease is linked to plaques and tangles in the brain — protein clumps that appear to wreak havoc in the brain.

There are genetic risk factors, and several genes seem to be involved. Perhaps the most well-known one is the gene APOE. One version of this gene, APOEε4, is associated with a significantly increased risk for Alzheimer’s.

However, this does not mean we’re powerless.

Different lifestyle factors appear to be able to modulate the risk for developing Alzheimer’s your genes may or may not predispose you to. Both physical and mental activity can reduce your risk. Physical exercise is good for you, including for your brain. But mental exercise matters too. Reading, writing, playing games, learning a new language, making music… All these activities seem to protect you against Alzheimer’s to some degree. One hypothesis is that these activities build up a cognitive reserve, which can delay the disease manifestation.

(So, reading this article is doing you — and your brain — a favor.)

Diet, too, plays its part. It’s difficult to point the finger at a specific nutritional element. Nutrition is complex.

People who eat a Japanese or Mediterranean-styled diet, seem to have a lower risk for Alzheimer’s. On the other hand, people with a high intake of saturated fat and refined carbohydrates, appear to increase their risk of developing the disease. Without getting into the dietary details, it’s interesting that diet — which we tend to associate with our guts — is linked to Alzheimer’s disease — which we tend to associate with our brains.

Yet, as we learn more and more about the microbial inhabitants of our guts, we’re beginning to see that their miniature tentacles reach far and wide in our bodies and even affect our personality. The gut-brain axis is a busy highway.

A recent study even suggests that the plaques associated with Alzheimer’s disease might travel across this highway as well. Mice injected with plaques in their gastro-intestinal tract displayed symptoms of Alzheimer’s after a year, and the researchers observed the plaques traveling upwards during that period.

Kind gut, strong brain?

If we can stop our gut microbes from making these plaques, could this help us prevent Alzheimer’s? Maybe we can give the ‘good’ microbes a boost and make sure they’re the primary inhabitants of our gut habitat?

A new study in mice suggests something along these lines.

Mice genetically ‘preprogrammed’ (aka purposefully genetically altered) to develop Alzheimer’s disease were found to harbor more pro-inflammatory microbes in their guts than normal mice. The researchers noticed that the dysbiosis (an ‘unbalanced’ gut microbiome) accelerated the development of Alzheimer’s.

Interestingly, they also found that a specific prebiotic supplement (R13) seemed to prevent this — and it also prevented the plaques from building up in the gut from where they might go on an excursion to the brain:

The prebiotic R13 inhibits this pathway and suppresses amyloid aggregates in the gut.

Of course, mice are not humans. Their microbiome, metabolism, brain, and so on will differ. Nevertheless, the biological mechanisms through which R13 operates (a tale of receptors, pathways, and other characters) could have an equivalent in human beings. At least, there seems to be enough potential to warrant a phase I trial in humans, which has already been approved and is being set up:

Currently, R13 is under phase 1 clinical trial for treating AD indication.

Does this mean we can throw caution to the wind?

Of course not. Why wait for a supplement when you can already do things right now to improve or maintain a healthy gut and healthy brain?

Eat healthy, get some movement, and, of course, don’t forget to read.