On a recent episode of APDA’s Dr. Gilbert Hosts, Dr. Gilbert spoke with Dr. Malu Gamez Tansey, the James A. Caplin, MD Chair in Alzheimer’s Disease at Indiana University School of Medicine and Director of Neuroimmunology Research Group, with expertise in the relationship between gut inflammation and Parkinson’s disease (PD).
We covered a lot of ground during the broadcast and answered questions from the audience. It was a very informative conversation, and we encourage you to watch the full episode, 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. Additionally, today we are answering some of the important questions that we didn’t have time to get to during the program.
Watch the full webinar on the gut and Parkinson’s disease with Dr. Tansey:
Questions Around Gut, Diet, and Parkinson’s Addressed During the Episode
26:15 What is the difference between prebiotics and probiotics and which ones can help with PD?
28:20 Which environmental factors are already known to induce gut inflammation linked to PD?
31:25 Can people with GI discomfort and constipation modify these symptoms through diet?
35:00 Are there screening methods you would recommend to establish whether a patient has gut inflammation?
38:30 Is there a relationship between gluten, inflammation, and PD?
41:44 Do negative GI symptoms contribute to making PD worse?
43:19 Is there any relation to microplastics as a cause in GI symptoms within PD?
46:44 What are beneficial things to eat if you have PD?
49:48 What are the implications if you have to take antibiotics with PD?
51:10 Is there a future for fecal transplantation for PD?
54:28 Is there a role for anti-inflammatory medications in PD?
Answering More Questions about Parkinson’s, Gut, and Microbiome
Here are some additional audience questions that we did not have time to get to during the broadcast:
Q: How does omeprazole, a proton pump inhibitor (PPI), affect the microbiome?
A: Long-term use of omeprazole and related PPIs can alter the gut microbiome by reducing stomach acid. This protects against ulcers and reflux but also reduces the body’s natural defense against bacteria. Over time, this can allow small intestinal bacterial overgrowth (SIBO), causing bloating, diarrhea, or malabsorption. PPIs also shift gut microbiome balance, which may be important since PD itself is linked with microbiota changes. This does not mean PPIs are unsafe, but people on long-term therapy should be monitored for gut side effects and should regularly review with their doctor whether the dose is still needed.
Q: Is Mannitol helpful in treating the GI symptoms of PD?
A: Mannitol is a sugar alcohol used medically to reduce brain swelling and studied experimentally in PD for possible neuroprotection. Taken orally, it acts as a strong laxative, often causing diarrhea, bloating, and cramping. These side effects make it unreliable as a constipation treatment, and clinical trials have not shown benefit for PD gut symptoms. Safer, targeted constipation treatments are recommended instead.
Q: Do any Parkinson’s medications cause GI symptoms?
A: Yes, several PD medications affect the gut and can cause GI symptoms in some people. However, not all people have these side effects. And more importantly, PD medications are essential to help with the movement problems of people with PD. Therefore, the positives and negatives of each medication need to be weighed for each individual person. Here are some potential GI side effects of various PD medications:
- Carbidopa/levodopa: nausea, especially when the medication is started. Taking the medication with food can be helpful to prevent nausea. However, foods that contain dietary protein can interfere with carbidopa/levodopa absorption. Therefore, taking the medication with carbohydrate-rich foods (e.g. crackers) is a better strategy.
- Dopamine agonists: nausea and occasional vomiting.
- Anticholinergics: constipation and dry mouth.
- MAO-B inhibitors: sometimes mild stomach upset.
Because PD already slows digestion, even small side effects can feel amplified in certain people. Adjusting timing, dose, or adding anti-nausea support often helps.
Q: What is the relationship between PD and inflammatory bowel disease (IBD)?
A: Research shows that people with IBD, which includes ulcerative colitis and Crohn’s disease may have a slightly increased risk of PD. It is important to note that most people with IBD will never develop PD—but the overlap highlights how closely gut and brain health are connected.
Q: Is Curcumin helpful in reducing gut inflammation in PD?
A: Curcumin, found in turmeric, has anti-inflammatory and antioxidant effects in lab studies. Some small trials suggest it can lower gut inflammation, but strong clinical evidence in PD is lacking. More research is needed to support its use in PD. It must be noted that absorption of curcumin is poor unless taken with fat or piperine (from black pepper). Cooking with turmeric is safe, but high-dose curcumin supplements should only be used with medical guidance due to possible drug interactions.
Q: When my husband was prescribed prednisone for a skin condition, his PD symptoms improved. Should prednisone be used for PD?
A: Steroids like prednisone reduce inflammation and may give temporary relief of stiffness or fatigue, but they are not safe for long-term PD treatment. Side effects include osteoporosis, diabetes, high blood pressure, infection risk, and mood changes. Researchers are exploring anti-inflammatory approaches to PD, but prednisone is too risky outside of short-term use for other conditions.
Q: If the GI symptoms of PD are causing a person to lose weight, what are the best strategies to overcome that?
A: Unintended weight loss is unfortunately a common non-motor symptom of PD. It can worsen fatigue and muscle weakness. Helpful strategies to counteract weight loss include:
- Eating small, frequent, calorie-dense meals.
- Adding healthy fats contained in foods such as avocado, nut butters, and olive oil.
- Treating underlying GI issues such as constipation or nausea which can make eating less enjoyable.
- Working with a dietitian to balance calories, protein, and fiber.
If weight loss persists, more advanced nutritional support may be needed.
Q: Is pelvic floor dysfgreen-font-colorunction a common problem in PD and a contributor to constipation?
A: Yes. In PD, pelvic floor muscles may not relax properly, making bowel evacuation incomplete. This “outlet obstruction” type of constipation is common but often overlooked. Laxatives alone may not help. Treatments include pelvic floor physical therapy, biofeedback, and posture changes such as using a footstool to improve bowel angle. Addressing pelvic floor dysfunction can make constipation management much more effective.
Tips & Takeaways
- GI symptoms are common in PD and deserve the same attention as movement issues.
- Check medications: PD drugs and proton pump inhibitors like omeprazole can affect gut health.
- Be cautious with remedies: Mannitol and prednisone are not recommended for PD gut symptoms despite anecdotal effects.
- Address constipation fully: It is not just slow gut motility that contributes to constipation. Pelvic floor dysfunction may need targeted treatment as well.
- Prevent weight loss early: Small, frequent calorie-dense meals and dietitian support can help maintain weight and strength.
- Consider safe anti-inflammatory options: Curcumin and a healthy diet may support gut health, but evidence in PD is limited.
- Always talk to your doctor about any new symptoms or concerns so they can help you find solutions.
- Go deeper on this topic and watch our previous webinar on the Gut and Parkinson’s from 2022.