The exact cause of PD remains unknown, but current theories suggest that it results from a combination of hereditary or genetic factors (i.e. family traits ) and exposure to unknown substances in the environment. The purpose of this study is to investigate whether toxins produced by bacteria that live within the nasal canal (nose) and the intestines of people with PD might have a role in causing the disease. The investigators in this study would like to look at the types of bacteria that live in the nasal canals and intestines of PD subjects and compare them with those of subjects who do not have PD.

Inclusion Criteria:

- 1. Patients with a clinical diagnosis of Parkinson's disease by United Kingdom Parkinson Disease Society Brain Bank criteria will be recruited.

2. Hoehn & Yahr stage 1-3 3. Parkinson's disease symptomatic treatment will be allowed. 4. Subjects with deep brain stimulation are allowed.

Exclusion Criteria:

• 1. Occupation expected to change intestinal flora pattern (e.g. sanitation worker) 2. Treatment with medications that may induce parkinsonism (metoclopramide, typical, or atypical antipsychotic agents) 3. Treatment within 12 weeks with systemic antibiotics 4. Known diagnosis of inflammatory bowel disease 5. Symptomatic organic GI disease other than hemorrhoids and hiatal hernia or abdominal surgeries for symptomatic GI disease such as bowel resection, diverticular surgery, colostomy, etc (subjects with a history of an appendectomy or cholesytectomy for benign disease more than 5 years prior to presentation are allowed).

  6. Symptomatic functional GI disease that significantly impairs intestinal motility such as scleroderma or use of GI motility drugs 7. Acute illness requiring immediate hospitalization 8. Pre-existent organ failure or comorbidities as these may change GI flora:

  1. Liver disease (cirrhosis or persistently abnormal AST or ALT that are 2X> normal);
  2. Kidney disease (creatinine>2.0 mg/dL);
  3. Uncontrolled psychiatric illness;
  4. Clinically important lung disease or heart failure;
  5. HIV disease;
  6. Alcoholism, unreliable drinking history; or consumption of alcohol more than 3 times a week or binge drinking or drinking more than or equal to 3 drinks per occasion;
  7. Transplant recipients;
  8. Diabetes;
  9. Clinically significant dehydration or clinically detectable ascites or peripheral edema or cardiac failure 9. Presence of short bowel syndrome or severe malnutrition with ideal body weight < or = 90% or 10. Estimated survival <1 year and Karnofsky performance status <50%; 11. Use of immunosuppressive medications within 3 months of enrollment 12. Chronic use of diuretics

Early to moderate stage Parkinson's disease subjects.