Hope or hype? FMT for Parkinson's needs more 'proper research'

Constipation is a common complaint in patients with Parkinson's disease (PD). What's more, research​​ has suggested that the gut mcrobiome could become a prediction tool for Parkinson's Disease. 

Therefore faecal microbiome transplantation (FMT) and pre- and probiotics have been considered as potential options for treating constipation and restoring the microbiome of patients with Parkinson's disease (PD), but scientists warn that clinical data is scarce and more 'proper research' is needed before supporting their use.

In a review article in the Journal of Parkinson's Disease​, investigators from University of Groningen in The Netherlands, evaluate the current state of knowledge about the potential for using microbiome modulators to restore the normal microbial balance of the gut in PD patients and highlight the questions that still need to be answered.

Lead investigator Teus van Laar, MD, Ph.D., director of the Parkinson Expertise Center at the university, says that FMT is a 'black box' as little is currently known about optimal content of FMT, the route of administration, the volume of FMT and the long-term effects.

"It is an attractive technique because the administration is relatively simple and in general it has only a mild pattern of adverse effects,"​ he says. "However, no rigorous clinical trials have been performed yet, which leaves multiple questions open about the presumed optimal content of FMT, the route of administration, the volume of FMT and the long-term effects.​

"FMT is a black box with too many unanswered questions at the moment, also with respect to safety concerns. ​FMT or the use of pro- and prebiotics might become standard treatments in selected subgroups of PD patients in the future, but there are no good data yet in the public domain to support their use in PD patients. We hope this review will activate colleagues to start proper research on this topic as soon as possible, rather than to begin therapy without conclusive clinical data."​​

The investigators recommend that FMT treatments in patients with PD should wait until better clinical data becomes available in order to select the right target populations and have good estimates of anticipated clinical effects. They highlight several knowledge gaps that need to be addressed first:

• FMT has not yet proven to be effective on motor symptoms or progression of PD
• Which route of administration of FMT is optimal
• Optimal donor content and frequency of FMT in PD
• Probiotics in PD have so far only been shown to have an effect on constipation
• Prebiotics have only been shown to have an effect in animal models and have not yet been tested in clinical trials
• Possible adverse effects and possible contra-indications of FMT are still unknown

Previous research

Administration of Lactobacillus and Bifidobacterium over a period of 4-12 weeks has repeatedly proven to be effective in treating constipation in PD. However, there is no solid clinical data available showing the possible effects of these probiotic treatments on motor symptoms or progression of PD.

Following promising results of prebiotics in animal studies, the first clinical trial on the use of FMT in PD patients is now underway at the University of Ghent (Belgium) and is scheduled to be completed by the end of 2019. With target recruitment of 40 PD patients and follow-up intervals of three months for up to one year, the trial will assess the development of PD symptoms. Investigators noted that the trial's inclusion criteria did not include or exclude constipation, which may complicate the interpretation of results.

Source: Journal of Parkinson's DiseaseVan Laar. T., et al"Faecal Transplantation, Pro- and Prebiotics in Parkinson's Disease; Hope or Hype?"​
DOI: 10.3233/JPD-191802​