Parkinson’s disease is often thought of as a neurodegenerative disease that begins in the brain. But what if it’s actually two separate diseases that start in different parts of the body? According to a new brain imaging study, researchers from Denmark found that in some people with Parkinson’s, damage to the nervous system begins in the gut and then travels to the brain. This new study finally explains why patients with Parkinson’s could experience widely different symptoms.
“Until now, many people have viewed the disease as relatively homogeneous and defined it based on the classical movement disorders. But at the same time, we’ve been puzzled about why there was such a big difference between patient symptoms. With this new knowledge, the different symptoms make more sense and this is also the perspective in which future research should be viewed,” says neuroscientist Per Borghammer from Aarhus University in Denmark.
The findings were made after researchers analyzed 37 patients all between the ages of 50 and 85 using advanced imaging techniques over six years. In the study, a significant number of the participants also had a REM sleep disorder closely tied to the disease, and the team found that this particular issue, which results in people acting out their dreams, tended to signal a body-first progression of Parkinson’s.
The researchers believe this is due to the fact that the disease is first travelling from the gut to a part of the brain closely tied to REM sleep, before making its way to the substantia nigra, which is where brain-first Parkinson’s tends to originate.
Gut-first Parkinson’s Vs. Brain-first Parkinson’s
“For some patients, the disease starts in the intestines and spreads from there to the brain through neural connections. For others, the disease starts in the brain and spreads to the intestines and other organs such as the heart,” explains Borghammer.
The gut was first tied to Parkinson’s disease nearly two centuries ago. Today, constipation is acknowledged as one of the most common symptoms of the condition, and yet it was only in 2003, after closely studying cadavers, that neuroanatomist Heiko Braak proposed a gut origin for Parkinson’s.
“It has long since been demonstrated that Parkinson’s patients have a different microbiome in the intestines than healthy people, without us truly understanding the significance of this. Now that we’re able to identify the two types of Parkinson’s disease, we can examine the risk factors and possible genetic factors that may be different for the two types. The next step is to examine whether, for example, body-first Parkinson’s disease can be treated by treating the intestines with faeces transplantation or in other ways that affect the microbiome,” says Per Borghammer.
Since then, further studies have produced mixed opinions. But that doesn’t mean the gut’s nervous system, known as the enteric nervous system, isn’t involved. “Previous studies have indicated that there could be more than one type of Parkinson’s, but this has not been demonstrated clearly until this study, which was specifically designed to clarify this question,” says Borghammer.
In the end, regardless of how Parkinson’s disease begins, all patients eventually develop severe damage to their sympathetic nervous system. This means both variants end up looking very similar – whether it’s the dopamine system in their brains that begins degenerating first, or their peripheral nervous system.
Why your Microbiome could help prevent Parkinson’s Disease
Parkinson’s Disease is a disorder in which the region of the brain that controls movement deteriorates due to lower dopamine levels, which is a neurotransmitter responsible for coordinated movement, mood, memory and other functions.
While it’s not fully understood what causes the dip in dopamine in the first place, we do know that an estimated 90% of the body’s serotonin, another well-known neurotransmitter is made in the digestive tract. Why is this relevant? It’s because ~50% of the body’s dopamine is also produced in the gut by enteric neurons and intestinal epithelial cells. And with this new study that came out, it goes without saying that your gut health is more important now than ever.
In addition, the microbes in your gut have a major influence on your metabolism, body weight, propensity to illness, immune system, appetite and mood. Here’s how you can give them a helping hand…
- Aim for 30-40g of fiber each day.
- Eat as many variety of fruits and vegetables as possible.
- Choose food and drinks with high levels of polyphenols. (green tea, berries, dark chocolate, olive oil)
- Eat plenty of fermented foods. (yoghurt, kefir, sauerkraut, kimchi, natto)
- Avoid artificial sweeteners like aspartame, sucralose and saccharine, which have been shown to reduce gut diversity.
- Spend more time in nature. (gardening, hiking)
- Add Omega-3 fatty acids into your diet. (salmon, sardines)