The human intestinal tract harbors a diverse and complex microbial community, known as gut microbiota, which is critical in sustaining physiology, metabolism, nutrition and immune function. Imbalance of gut microbiota (dysbiota) has been linked with obesity, hyperglycemia, hyperlipidemia, hypertension, inflammatory bowel disease and other chronic inflammatory diseases. Gut microbiota is affected by host genetic makeup, diet and lifestyle; and therefore varied by human races and geographical locations


This study aims at understanding the structure and characteristics of the gut microbiota and their epidemiological and health correlations in the general population in different geographical locations.

Description of interventions

  • One-off stool collection for microbiome analysis
  • Completion of health/lifestyle questionnaire
  • Measurements of blood pressure, hip circumference and BMI

Eligibility criteria

Inclusion criteria

  • Persons living in the UK for more than 3 years.
  • BMI >18
  • Age 18-70 (no limit on gender)*
  • Able to give informed consent
  • Able to provide required stool sample and complete questionnaire in English.

Exclusion criteria

  • Subjects who are unable to give consent or who have conditions rendering them incapable to answer questionnaires or provide stool samples.
  • Use of prebiotics, probiotics, antibiotics or PPI in the last 3 months
  • Known complex infections or sepsis (excluding uncomplicated infections such as influenza)
  • Known history of severe organ failure (including liver failure, kidney failure)
  • Known history of epilepsy, active serious infection, acquired immunodeficiency syndrome, cancer, inflammatory bowel disease, irritable bowel syndrome, diabetes mellitus, cirrhosis or HIV
  • Known history of severe psychiatric illness (such as mania and schizophrenia)


Chief investigator:

Prof Siew C. Ng, MBBS(UK), FRCP (Lond, Edin), PhD (Lond), AGAF, FHKCP, FHKAM (Medicine), Assistant Dean (Development), Faculty of Medicine; Associate Director, Center for Gut Microbiota Research; Professor, Department of Medicine and Therapeutics, Institute of Digestive Disease, The Chinese University of Hong Kong

Tanya Monaghan

Jane Grove