Parkinson’s Disease & the Gut

Dr. Gilbert Answers Questions About Parkinson’s Disease and Gastrointestinal Issues

On a recent episode of APDA’s Dr. Gilbert Hosts, I spoke with Dr. Ali Keshavarzian, a gastroenterologist with expertise on Parkinson’s disease and the gut. We covered a lot of ground and during the broadcast and answered questions from the audience.

Further Reading: Learn about Parkinson’s disease and the microbiome

Highlights From the Episode

It was a very informative conversation, and we encourage you to watch the full episode (just click the video below), but for your convenience we’ve listed the topics and questions from the episode below with timestamps, so you can skip to what interests you most:

03:41 Dr. Keshavarzian’s presentation

28:15 Diarrhea in Parkinson’s disease

34:04 How many years does constipation show up before a diagnosis of Parkinson’s? How many years may you develop small intestinal bacterial overgrowth (SIBO) before a diagnosis of Parkinson’s?

40:07 What are your thoughts on the use of probiotics in someone with Parkinson’s?

44:20 Use of prebiotics in someone with Parkinson’s

48:59 Pelvic floor physiotherapy

But there were many more questions that came in that we didn’t have time to answer during the live broadcast. Today we present some of those additional questions and their answers.

Answering your questions about Parkinson’s and Gut Health

Q. Can PD contribute to the development of hernias?

A. Chronic constipation which could be related to PD can lead to chronic straining which is a risk factor for developing hernias. To avoid this complication, make sure chronic constipation is treated! There are numerous treatments to address constipation and you can read about them in this fact sheet.

Q. What medication can work for bloating?

A. The first thing to determine is why you are having this symptom. There are many causes of bloating; some are related to PD and some are not. It is important to always keep in mind that a person with PD can also have another unrelated disease, so a thorough investigation of every symptom is necessary. 

However, there are at least two common causes of bloating that are related to PD – gastroparesis, also known as delayed gastric emptying, and constipation. Gastroparesis is treated with lifestyle changes which include eating small frequent meals, drinking fluids during meals, avoiding fat, and taking a walk after eating. In some cases, a medication called prucalopride (Motegrity) can be tried to enhance the motility of the gut. Constipation is also treated with lifestyle changes including eating meals at the same time of day, adding fiber to the diet, and eliminating medications that can contribute to constipation. There are many medications on the market – both over-the-counter and by prescription – that can be very effective to counteract constipation. Many people need to be on a daily medication to keep constipation in check. These medications include: docusate (Colace), senna (Senokot), and polyethylene glycol (Miralax).

Read our fact sheet for more information on treatments for constipation

Q. Are there vitamins or herbs that help the PD gut?

A. Many people ask if there is a particular supplement, vitamin, or food that people with PD should take to improve their gut health and it is hard to find evidence for a specific supplement. However, as Dr. Keshavarzian said, a great diet for the PD gut is the Mediterranean diet. This diet emphasizes whole grains, vegetables, nuts, legumes, and berries. Fish is the preferred protein and olive oil is the preferred fat. So it seems that a combination of healthy, plant-based eating does more for PD than any one element of that diet.

Q. Please discuss fecal matter transplants in people with PD

A. Fecal transplantation is a technique in which fecal matter from a healthy person is delivered to the gut of a person with a disease, with the goal of restoring a healthier microbiome (defined as the trillions of micro-organisms that live inside the human gut). Only case reports and very small studies have been reported so far in the literature about whether this helps people with PD, but this may be an area worth exploring. There are a few additional studies underway which you can read about here:

We await the results of this research to assess whether fecal transplantation will prove to be useful for patients with PD.

Q. Can you discuss how protein intake and Sinemet interact?

A. You are referring to the “protein effect”, which means that for some people with PD, eating dietary protein (meat, chicken, fish, eggs, etc.) can interfere with the absorption of levodopa. If you do not have this problem and protein does not interfere with medication absorption, then there is nothing to worry about. The way to determine if you have this problem or not is to take a dose of medication with and without the food of interest and note your response to the medication. If it is the same, then you can continue eating whatever you like, whenever you like. If the protein does seem to decrease the efficacy of your medication, then the solution is to wait about one hour between protein ingestion and taking medication. Many people simply eat meals without protein during the day and save their protein for the evening meal when they do not expect to be as active. You can read more about how to deal with this and other issues relating to food and carbidopa/levodopa in this article.

Q. Is there a higher incidence in PD sufferers of celiac disease, colon cancer, and other gastrointestinal disorders?

A. There is no evidence that risk of colon cancer specifically is increased in people with PD. This means that people with PD should get the same colon cancer screening as the general population. The same is true for celiac disease. A recent study did not demonstrate a statistically significant association between celiac disease and PD. 

As Dr. Keshavarzian discussed at length, PD itself can cause many GI symptoms (constipation, bloating, diarrhea, abdominal pain, nausea) and these symptoms can overlap with other GI conditions (such as colon cancer and celiac disease). Therefore, if a person with PD has a new GI symptom, he/she should not assume that it is related to PD. Rather a more thorough GI evaluation needs to be performed.

Q. What is your opinion of a ketogenic diet with PD?

A. A ketogenic diet is a high fat, moderate protein, and very low carbohydrate diet that forces the body to burn fat as opposed to carbohydrates. It is used clinically to control seizures in children with very difficult-to-control epilepsy.

There have also been some studies to suggest that the ketogenic diet may have a neuroprotective effect, which led to the interest in studying the diet in PD. A recent study compared a low fat versus a ketogenic diet in PD. Interestingly, both diets resulted in improvement of motor scores, whereas the ketogenic diet showed improvement in non-motor scores as well.

It must be noted that the ketogenic diet is very restrictive and therefore very difficult to follow. In addition, it can pose health risks as well, especially to the elderly. It requires ingestion of high levels of fat which is linked to increased cholesterol and heart disease. It also requires a very limited ingestion of foods such as fruits and grains – foods that provide nutrients and fiber. With such a limited array of permissible foods, there is a risk of nutrient deficiencies. Constipation, which is often a non-motor feature of PD can be exacerbated as well with a ketogenic diet. Because of the restrictive nature of the diet, it can lead to weight loss, an effect that is not typically desired in the PD population which can have difficulty maintaining weight.

At this point, more data is needed about the benefits of the ketogenic diet for PD to determine if they outweigh the potential risks.  As previously stated, a Mediterranean diet is a smart choice for people with PD.

Q. Can constipation contribute to anxiety?

A. Constipation and anxiety can be a two-way street. Being anxious about not being able to defecate can worsen constipation and being constipated can worsen anxiety. 

Q. Once a course of antibiotics has been administered for a small intestinal bacterial overgrowth (SIBO), what is the next step in the treatment?

A. The goal of the course of antibiotics is to treat SIBO, which can induce bloating, diarrhea, and abdominal pain. SIBO is a chronic condition, and may return over time, causing a return of symptoms. If symptoms return, another course of antibiotics may be prescribed.

Q. I was diagnosed with irritable bowel syndrome (IBS) and also have PD. How do I know whether my symptoms which include alternating diarrhea and constipation are due to IBS or PD? 

A. Irritable bowel syndrome refers to a poorly understood and very common constellation of symptoms including abdominal pain, bloating, diarrhea, and constipation without an associated increase of inflammation in the gut wall or increased risk of cancer. The symptoms might overlap with PD symptoms to such a degree that it might be impossible to distinguish between the GI symptoms of PD and IBS. 

Q. Can a person with PD have an odd taste in their mouth? 

A. People with PD can have decreased ability to taste and have different taste preferences than the general population. They can also have altered taste as compared to the general population. Unfortunately, there are no effective treatments for these taste issues.

Q. Is Prucalopride effective? Are there side effects?

A. The medication prucalopride (Motegrity) is a selective serotonin-4 receptor agonist that improves bowel motility. It was approved in 2018 to treat chronic constipation as well as gastroparesis or delayed gastric emptying. Common side effects include GI symptoms, headache, fatigue, and dizziness. Less common is its potential to cause changes in mood including depression.

Tips & Takeaways

  • Gastrointestinal symptoms of constipation, diarrhea, bloating, nausea, and abdominal are very common in PD
  • Listen to a broadcast dedicated to answering questions about GI issues and PD
  • If you have a PD-related question, you can submit it to our Ask A Doctor portal

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