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New insights about Parkinson's disease - and the meaning for medicine

In recent years it turned out that long before the first symptoms of Parkinson's appear, it is possible to find a change in the population of intestinal bacteria of the patients

Parkinson's disease. Illustration:
Parkinson's disease. Illustration:

Parkinson's disease is one of the most well-known - and most severe - diseases of old age. Its patients have difficulty moving their arms and legs, suffer from tremors, dementia (madness), depression and many other severe symptoms. Like Alzheimer's disease, it is a neurodegenerative disease - that is, one in which the nerves in the brain degenerate and die over many years. But now a new study may show that the disease actually begins in the intestines - and it is possible to prevent half of the disease's cases with simple treatment.

The big question, what causes Parkinson's disease, has accompanied medical science since the disease was first discovered. We know that nerve cells - neurons - which are responsible for producing dopamine, die at an increased rate in the brain. The main suspects in the murder of nerve cells are called "Lewi bodies". These are actually tiny particles that are formed as a result of the accumulation of fibers that the cells themselves produce. 

A little over twenty years ago, one of the researchers of the disease put forward A bold idea: He proposed that the same fibers that are responsible for Parkinson's disease are produced in the area where the brain receives messages from the intestinal area, and from there go up to the place where they kill the nerve cells that produce dopamine. In 2015, an interesting evidence for the theory was discovered: when you completely cut the main nerve that connects to that area of ​​the brain, the risk of developing Parkinson's disease reduced by fifty percent

but why? What is so special about that nerve - called the "vagus"? Why exactly are the harmful fibers produced there?

Here the answer becomes even stranger, and relies on another finding from recent years: it turns out that long before the first symptoms of Parkinson's appear, it is possible to find a change in the population of intestinal bacteria of the patients

The microbiome

In recent years we understand more and more that we are not alone in our own body. We share our bodies with a vast wealth of bacteria, viruses, fungi and worms. All of these are collectively referred to as the "microbiome": the world of microscopic creatures living in the depths of our bodies. 

Most of these microscopic creatures have found a particularly comfortable place for themselves: a moist and juicy den through which food is constantly passing. I mean, of course, the intestines. In the intestines alone you can find a number of bacteria that at least equals the number of all human cells in the body. Every time you eat a good meal, you feed several tens of trillions of bacteria that live in your gut, and belong to 5,000 different species. Their total weight together comes to approximately two kilograms - A little more than the weight of the human brain

It is not surprising to find that all these bacteria affect our health in different ways. We know today that the variety of bacteria in the intestines can encourage obesity, metabolic disorders and even cause the outbreak of autoimmune diseases in which the body attacks itself. Gut bacteria produce materials that affect brain activity like serotonin, produce vitamins and enzymes that are involved in the body's metabolism. Change the composition of the bacteria - and you will get a different person!

And maybe - just maybe - you can prevent the onset of Parkinson's disease.

The new research

In the new study, published in May 2024, the researchers went through stool samples from 94 Parkinson's patients from Japan (and 73 healthy controls), and compared them to similar samples from patients from previous studies and from other countries. They looked at the bacterial populations that change in Parkinson's patients, and found, well, a mess.

It turns out that in Parkinson's patients from different countries, you can find different levels of different bacteria in the intestines. strange? Not so. People in different countries eat different foods - from the anona fruit with its jagged prongs to beef tongue. The diet affects the population of bacteria in the intestines, helping some of them to grow and harming others. So far, the research is not particularly interesting. But the researchers continued and examined the bacterial genes that were damaged in Parkinson's patients. 

There the first great discovery was made.

Out of all the huge differences between the genes, it was possible to distinguish one category of genes that were particularly affected: those related to the production of riboflavin and biotin. Both of these are variations of vitamin B. Riboflavin is also known as vitamin B2, and biotin is vitamin B7. The researchers suggest that it is possible that the lack of these two vitamins - caused by the difference in the intestinal bacteria - is one of the causes of Parkinson's disease. Or at the very least, the deficiency contributes to the development of the disease. 

This idea is not as strange as it may seem at first glance. we know shriboflavin Improves the body's ability to deal with oxidative stress and inflammation in the area of ​​nerve cells, and improves mitochondrial function. All of these are also related to protection against Parkinson's disease. In a past clinical study, a high dose of riboflavin Improved motor function of Parkinson's patients. Biotin, in turn, helps produce anti-inflammatory substances, although so far it has not been linked with Parkinson's disease in any way.

This discovery brought to the researchers' first conclusion: Give them vitamin B. They suggest that the administration of riboflavin and biotin (as mentioned, vitamin B2 and B7), may have a positive effect on some Parkinson's patients and prevent, delay and minimize the development of the symptoms of the disease. 

But this, as mentioned, is only the first conclusion.

The researchers continued and discovered another strange phenomenon: as the amount of genes responsible for the production of riboflavin and biotin decreased, so did the concentration of certain substances in the intestines. Those substances belong to the "short-chain fatty acids" and polyamines groups. Why is their concentration impaired? Probably because riboflavin participates in the production of polyamines, and therefore Damage to riboflavin will also lead to damage to polyamines. And biotin? Its relation to the production of fatty acids or polyamines is unknown - but there is probably something to investigate here. 

And why do we even care that polyamines and short-chain fatty acids are damaged? These substances are involved in the formation of the mucous membrane which protects the intestines ours from the inside. Lower concentrations of these substances lead to mucosal damage. It may sound like a minor thing, but this lining is one of the mechanisms that prevent harmful toxins from seeping into the body through the intestines. 

The researchers' second conclusion, therefore, is that the difference between the intestinal bacteria causes damage to the mucosa - which in turn allows toxins from the environment to reach the body, and especially to the nerves adjacent to the intestines. The nerves react by creating harmful fibers, and these connect together and become Lewy bodies, which eventually also reach the brain and cause Parkinson's disease.

If all of this sounds to you like one big murder mystery, with a sequence of logical keys that should lead to the final solution - well, you are right. This is what medical science looks like: we try to reach an understanding of complex diseases, with a large number of possible causes, based mainly on circumstantial evidence. Perhaps there is a reason why the word "investigators" describes both police investigators and scientific researchers. Both have to reach conclusions from a paucity of evidence, which also sometimes takes years to obtain.

The positive side is that our research tools are getting better and better over the years, so our medical knowledge is also constantly growing. And it is only going to continue to grow in the coming years, with the advancement of technology for collecting information from the body.

From science to technology - and back

If I were just writing a normal popular science article here, I should have stopped at the last sentence. point. End of discussion. But the research I described about Parkinson's disease, for me, is just another link in the greater progress of science. And science, necessarily, is a product of existing technology. We could not understand how certain bacteria harm our health, for example, before the invention of the microscope that allowed us to discover that bacteria even exist.

What will be the technologies, then, that will continue to advance medical science in the coming years, with an emphasis on the microbiome. After all, we have already seen that the intestinal bacteria have a particularly large effect on our health. How can we understand them better?

One promising technology made headlines in June 2024, in a study published in the scientific journal Device. It may help us understand exactly what is happening in our eyes. And this, it turns out, is not a simple problem. To identify the bacterial populations in the intestines today, we need to do like those Parkinson researchers, and examine stool samples. Feces, after all, contain traces of gut bacteria. But the intestines are a very long organ, and bacteria that live at the beginning of the route - right after the stomach - will not necessarily end up in the toilet. 

To face the challenge, scientists at Tufts University in the United States recently developed an innovative solution to the problem: the microbiome pill. It is a small device, the size and shape of a typical vitamin pill. After the patient swallows the pill, it begins a journey along his digestive tract, capturing a wide variety of microorganisms along the way. 

The pill is equipped with a flexible shell that was printed in 3D. Along the entire length of the shell you can find openings that open and close depending on the acidity surrounding the pill. Tiny valves absorb moisture at the right times and areas in the gut, swell and seal the openings after the bacteria have penetrated the pill. The little treasure chest continues to move through the intestine together with the digested food, and when it is expelled from the other side of the body - the scientists can collect it and analyze its contents. Yes, it stinks, but the information there is worth its weight in gold. 

The researchers tested the pill in animals - pigs and dogs - and showed that it was able to collect bacterial samples from different areas of the intestine. This paves the way for clinical trials in humans, which could result in us all understanding our microbiome much better than the situation today. 

The promising future of medicine

Are we going to cure Parkinson's disease soon? probably not. Can we help restore, moderate or delay the onset of some of her symptoms? This is starting to sound more likely, given the evidence that is accumulating from studies. And when we understand that the tools for gathering evidence and understanding it are constantly being perfected and improved, it is possible to understand why futurists are optimistic about the future of medicine.

The two studies I described, which came out just one month apart, nicely demonstrate how different scientific and technological fields can reinforce each other. And the more artificial intelligence (because it is impossible to finish an article without mentioning it) will be further refined, the more it will contribute to the cycle of technology-improving-science-improving-technology. It will help researchers to more quickly apply new research technologies, generate insights and publish them. At the same time, it will help engineers develop new technologies based on scientific discoveries, and these in turn will contribute to promoting science as well.

Now we only have to take care of preserving this circle of science-technology-science, and cooperation between researchers and laboratories. We need to maintain international peace that will allow science and technology to continue to flourish and bear fruit. In all the years of existence of the human race, we are the closest to understanding the world around us and the world within us. To understand how to reach perfect health, and perhaps even an extreme extension of the healthy life span. What is called in the common parlance - "eternal youth". It's a dream - but there's no reason why it shouldn't be possible.

Just a few more years. Just a few more decades. As Professor Freddie Mercury, one of the great researchers of the state of human existence, claimed - "Don't stop us now".

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