Microbiome Composition and Function Contributes to Cognitive Impairment and Neuroinflammation in Parkinson's Disease

Parkinson Disease Clinical Trial

Official title:

Microbiome Composition and Function Contributes to Cognitive Impairment and Neuroinflammation in Parkinson's Disease

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT05419453
• Other study ID #: SC3NS124906
• Status: Recruiting
• Start date: April 30, 2021
• Est. completion date: April 2026

Study information

• Verified date: February 2024
• Source: California State University, San Bernardino
• Contact: Kenya Luna, B.A.
• Phone: 9094543135
• Email: gutbrainstudy1[@]gmail.com
• Is FDA regulated: No
• Study type: Observational

Clinical Trial Summary

Cognitive impairment is a common non-motor symptom among individuals living with Parkinson's disease (PD). Traditionally, cognitive impairment is thought to reflect disruptions in dopaminergic frontal-striatal systems. However, the current conceptualization does not thoroughly explain the heterogeneous profiles or trajectories of cognitive impairment in PD; suggesting that alternative mechanisms may contribute to cognitive impairments. Identification of alternative mechanisms of cognitive impairment may lead to better prognostic prediction and yield novel treatment targets. The gut is implicated as a site of early pathology in PD. Early signs of PD pathology (alpha synuclein and Lewy body aggregates) are detected in the gastrointestinal tract years before motor symptoms manifest. Recent studies provide evidence that individuals with PD have an altered gut-bacterial composition (termed dysbiosis) relative to controls. To date, dysbiosis is linked to more severe motor symptoms and certain non-motor symptoms (constipation, REM behavioral sleep disorder) in PD, but the relationship between dysbiosis and cognitive impairment remains unknown. Animal studies support the hypothesis that microbiota composition play a direct role in cognitive impairment. Germ free (GF) mice demonstrate deficits in cognition. Specifically, findings suggest that a disrupted gut- microbial environment in conjunction with elevated stress hormones may create an imbalance of pro- inflammatory vs. anti-inflammatory cytokines that induces potentially reversible cognitive impairments. In human studies among individuals with PD, neuroinflammatory markers are associated with cognitive impairment. However, the relationship between dysbiosis, neural inflammation and cognitive functioning remains unknown. This model has incredible clinical implications, as microbiota dysbiosis may represent a reversible risk factor for cognitive impairment. The proposed study will examine the hypothesis that dysbiosis contributes to increased neuroinflammation and cognitive impairment. Microbiota composition/function, neuroinflammatory markers and cognitive functioning will be examined in 100 participants with PD. Analyses of microbiota composition/function will examine abundance of amplicon sequence variants (ASVs; 16s), bacterial species/strains (metagenomics), microbial genes, and functional pathways. The investigators hypothesize that microbiota composition/function will be associated with inflammatory markers (e.g. interleukin-6, tumor necrosis factor-alpha, c-reactive protein) and cognitive impairment.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 100
• Est. completion date: April 2026
• Est. primary completion date: April 2026
• Accepts healthy volunteers: No
• Gender: All
• Age group: 55 Years to 85 Years

Eligibility

Inclusion Criteria:

• Parkinson's Disease

Exclusion Criteria:

• Use of antibiotics or immunosuppressant medications within the last 3 months, history of psychiatric hospitalizations, stroke, epilepsy, head injury resulting in a loss of consciousness for more than 30 minutes, Alzheimer's disease or other significant brain injury or neurologic event, history of inflammatory gastrointestinal diseases such as Crohn's, Celiac's disease or irritable bowel syndrome

Related Conditions & MeSH terms

• Cognitive Dysfunction
• Parkinson Disease

Locations

Country	Name	City	State
United States	California State University San Bernardino	San Bernardino	California

Sponsors (3)

Lead Sponsor	Collaborator
California State University, San Bernardino	National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH)

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Cognitive Impairment	Cognitive functioning as measured by a composite measure (average) of all neuropsychological tests	4 hours