As our understanding of the intricate relationship between the body and the brain continues to grow, scientists are turning their attention to the role of the microbiome in the decline of brain health.

New research suggests a fascinating link between gut bacteria and Alzheimer’s Disease, offering exciting possibilities for future therapies.

The prevailing medical consensus is that gut microorganisms — also known as gut bacteria — are effectively the gatekeepers of our digestive system. They aid in the production of vitamins, synthesise critical nutrients, and protect our bodies from harmful pathogens.

Recently, compelling evidence has come to light showing that these bacteria also play a crucial role in our overall well-being, as it was found that they could greatly impact our brain health, too.

Alzheimer’s is the most common form of dementia. It is a progressive degenerative disorder characterised by the accumulation of toxic proteins (amyloid and tau) in the brain.

A new study is investigating the relationship between gut bacteria and the development of Alzheimer's disease. Credit: Pexels/Kindel Media.

It is these proteins that are thought to affect neurons and lead to memory loss, confusion and other symptoms of this devastating disease.

A landmark 2017 study has previously uncovered a relationship between gut bacteria and the build-up of this toxic protein in mice. After more research, the scientists found that mice engineered to develop amyloid protein plaques displayed fewer brain amyloid aggregations when bred in the absence of gut bacteria.

Following this, new research went one step further to see how gut bacteria may be affecting tau accumulation, the other major pathogenic sign of Alzheimer's.

The initial tests looked at mice bred in a totally bacteria-free environment from the very beginning. They concluded that mice with high levels of tau proteins develop less neurodegeneration with age when raised sans gut bacteria compared to mice raised in a normal environment.

This bacteria-free benefit also applied to male mice who were given strong doses of antibiotics at two weeks of age.

However, when the same process was repeated with female mice, the results were more mixed, with no difference in results at 40 weeks of age.

Animals without gut microbes had lower rates of neurodegeneration than animals with normal microbiomes, according to research. Credit: Pexels/Edward Jenner.

No one just yet knows exactly why this sex-based difference occurred, although the researchers suspect it may have something to do with the hormones present in female mice that could be altering immune cell behaviour in the brain.

David Holtzman, the senior author of the study, said: 'We already know, from studies of brain tumours, normal brain development and related topics, that immune cells in male and female brains respond very differently to stimuli.'

'So it’s not terribly surprising that when we manipulated the microbiome we saw a sex difference in response, although it is hard to say what exactly this means for men and women living with Alzheimer’s disease and related disorders.'

Further research is required to understand why these metabolites may be triggering neuroinflammation in the brain and how exactly the gut microbiome works to initiate these changes.

However, reducing the levels of gut bacteria that produce these SCFA metabolities isn't feasible, since they are an important aspect of other healthy physiological functions.

Holtzman believes there may be ways to manipulate the microbiome and slow, or even prevent, neurodegeneration.

'What I want to know is, if you took mice genetically destined to develop neurodegenerative disease, and you manipulated the microbiome just before the animals start showing signs of damage, could you slow or prevent neurodegeneration?' Holtzman speculated.

Key Takeaways

• A study has shed more light on how the trillions of microbes in our gut could be affecting our brain health.
• The research found mice engineered to develop Alzheimer's developed significantly fewer signs of neurodegeneration when raised with no gut bacteria.
• The findings still need to be tested in people but could open the door to new treatments for neurodegenerative disease.

This discovery is certainly ground-breaking, however, it’s not a sign that we should all hurry out and buy probiotics straight away. We still have plenty more to learn before this new discovery can be turned into an actual therapy.

Currently, our best bets for warding off Alzheimer's-related memory loss remain diet and lifestyle changes as well as following the tried and tested adages 'use it or lose it' and 'prevention is better than cure'.

Every step closer to understanding the connection between our gut and brain health is a step closer to being able to stop Alzheimer’s in its tracks.

What do you think of this incredible discovery? Share your thoughts and opinions in the comments below!

 

[Ricci]

Maybe there's more to the old saying "you are what you eat" than we give credit for.

 

[Granny*Deb]

Food we consume is behind quite a few problems. I have Parkinson's Disease and it's now been discovered that that protein rich foods are better for us. But you need to make sure you don't consume too much protein around medication time as that impacts on your body absorbing all of your medication not just a portion of your meds as then tremors can return sooner rhan expected. It's like bloody russian roulette lol quite the juggling act.