The relationship between inflammatory bowel disease and Parkinson’s disease: true or fiction?

Abstract

Gastrointestinal (GI) symptoms can precede by many years the motor symptoms of Parkinson's disease (PD) and these patients can show some degree of inflammation associated with abnormal aggregates of alpha-synuclein in the GI tract. The abnormal accumulation of alpha-synuclein and the spreading of the aggregates from the gut to the brain might be promoted by inflammation, rising the hypothesis of a possible relationship between inflammatory bowel disease and PD. Many population-based studies have explored this association, but they have found conflicting results. It is essential to clarify this hypothesis and to try to elucidate the milestones of this relationship. There is no clear concordance between the results and the interpretation of different previous findings, probably due to many confounding factors such as drugs with anti-inflammatory activity, surgery, genetic predisposition and also selection bias. If there is a real association between both diseases, gastroenterologists and neurologists should be able to detect possible triggers of the disease or on the other hand, protective factors, that may be considered in clinical practice.

Keywords:

• Inflammation
• non-motor symptoms
• alpha-synuclein
• Parkinson’s disease
• inflammatory bowel disease

Disclosure statement

Dr. Rodríguez-Lago has served as a speaker, consultant and advisory member or has received financial support for travelling and educational activities from MSD, Pfizer, Abbvie, Takeda, Janssen, Tillotts Pharma, Shire Pharmaceuticals, Ferring, Dr. Falk Pharma and Otsuka Pharmaceutical. The remaining authors declare no potential conflicts of interest related to this manuscript.

Additional information

Funding

IR-L is supported by a research grant from Biocruces Bizkaia Health Research Institute [Grant No. INT-BC-2018-007].