title: Small intestinal bacterial overgrowth in Parkinson's disease.
abstract: BACKGROUND
  Recent studies reported a high prevalence of small intestinal bacterial overgrowth (SIBO) in Parkinson's disease (PD), and a possible association with gastrointestinal symptoms and worse motor function. We aimed to study the prevalence and the potential impact of SIBO on gastrointestinal symptoms, motor function, and quality of life in a large cohort of PD patients.
  
  
  METHODS
  103 Consecutive PD patients were assessed using the lactulose-hydrogen breath test; questionnaires of gastrointestinal symptoms and quality of life (PDQ-39); the Unified PD Rating Scale (UPDRS) including "on"-medication Part III (motor severity) score; and objective and quantitative measures of bradykinesia (Purdue Pegboard and timed test of gait). Patients and evaluating investigators were blind to SIBO status.
  
  
  RESULTS
  25.3% of PD patients were SIBO-positive. SIBO-positive patients had a shorter mean duration of PD (5.2 ± 4.1 vs. 8.1 ± 5.5 years, P = 0.007). After adjusting for disease duration, SIBO was significantly associated with lower constipation and tenesmus severity scores, but worse scores across a range of "on"-medication motor assessments (accounting for 4.2-9.0% of the variance in motor scores). There was no association between SIBO and motor fluctuations or PDQ-39 Summary Index scores.
  
  
  CONCLUSIONS
  This is the largest study to date on SIBO in PD. SIBO was detected in one quarter of patients, including patients recently diagnosed with the disease. SIBO was not associated with worse gastrointestinal symptoms, but independently predicted worse motor function. Properly designed treatment trials are needed to confirm a causal link between SIBO and worse motor function in PD.
authors.affiliation: Faculty of Medicine (Divisions of Neurology and Gastroenterology), University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Ai Huey
authors.initials: AH
authors.lastname: Tan
authors.affiliation: Faculty of Medicine (Divisions of Neurology and Gastroenterology), University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Sanjiv
authors.initials: S
authors.lastname: Mahadeva
authors.affiliation: Faculty of Medicine (Divisions of Neurology and Gastroenterology), University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Abdul Malik
authors.initials: AM
authors.lastname: Thalha
authors.affiliation: Department of Gastroenterology, Central Clinical School, Monash University and Alfred Hospital, Melbourne, Australia.
authors.forename: Peter R
authors.initials: PR
authors.lastname: Gibson
authors.affiliation: Faculty of Medicine (Divisions of Neurology and Gastroenterology), University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Chiun Khang
authors.initials: CK
authors.lastname: Kiew
authors.affiliation: Faculty of Medicine (Divisions of Neurology and Gastroenterology), University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Chia Ming
authors.initials: CM
authors.lastname: Yeat
authors.affiliation: Faculty of Medicine (Divisions of Neurology and Gastroenterology), University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Sheang Wen
authors.initials: SW
authors.lastname: Ng
authors.affiliation: Faculty of Medicine (Divisions of Neurology and Gastroenterology), University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Sheau Phing
authors.initials: SP
authors.lastname: Ang
authors.affiliation: Faculty of Medicine (Divisions of Neurology and Gastroenterology), University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Siew Kian
authors.initials: SK
authors.lastname: Chow
authors.affiliation: Faculty of Medicine (Divisions of Neurology and Gastroenterology), University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Chong Tin
authors.initials: CT
authors.lastname: Tan
authors.affiliation: Institute of Biological Sciences, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Hoi Sen
authors.initials: HS
authors.lastname: Yong
authors.affiliation: Morton and Gloria Shulman Movement Disorders Centre, Toronto Western Hospital and the Edmond J. Safra Program in Parkinson's Disease Research, University of Toronto, Toronto, Canada.
authors.forename: Connie
authors.initials: C
authors.lastname: Marras
authors.affiliation: Morton and Gloria Shulman Movement Disorders Centre, Toronto Western Hospital and the Edmond J. Safra Program in Parkinson's Disease Research, University of Toronto, Toronto, Canada.
authors.forename: Susan H
authors.initials: SH
authors.lastname: Fox
authors.affiliation: Faculty of Medicine (Divisions of Neurology and Gastroenterology), University of Malaya, Kuala Lumpur, Malaysia. Electronic address: limshenyang@ymail.com.
authors.forename: Shen-Yang
authors.initials: SY
authors.lastname: Lim
mesh_terms: D000368:Aged; D001424:Bacterial Infections / Q000150:complications / Q000453:epidemiology*; D005260:Female; D006801:Humans; D006859:Hydrogen; D007410:Intestinal Diseases / Q000150:complications / Q000453:epidemiology*; D007792:Lactulose; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000453:epidemiology*; D015995:Prevalence; D011788:Quality of Life / Q000523:psychology; D012044:Regression Analysis; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires
chemical_list: D007792:Lactulose; D006859:Hydrogen
keywords: Gastrointestinal dysfunction; Parkinson's disease/Parkinsonism; Small intestinal bacterial overgrowth