Background

Recent research has revealed that bacteria that live within and on the body play both a central and critical role in normal physiological function. While many bacteria appear benign, and others can cause disease, many provide benefit to us, helping us digest food and producing chemicals important to our health. It appears likely that humans and other animals, having evolved with a significant bacterial exposure on all surfaces (including our digestive and reproductive tracts), have come to rely on bacteria for a range of biological functions.

Studies specifically examining bacteria are limited, and particularly in humans. However, evidence supports a complex interaction between bacteria, the environment (including the digestive tract and the food it contains), the gut wall, and physiological processes (including immune and endocrine regulation). An altered, or ‘dysbiotic’, bacterial community in the gut has been linked with a range of disorders, and include irritable bowel syndrome (IBS), and mental health disorders like depression and anxiety.

In this project, we ask participants to provide information about their diet, and physical and mental health, and (for those eligible) provide a small faecal sample (for bacterial and metabolic assays), urine sample (for metabolic assays), saliva samples (for bacterial, metabolic, endocrine and immune assays), and a small hair sample (for endocrine assays).

“Where participants take part in the biological sample components, we will compare the bacterial and physiological profiles of four different types of participants: 1) healthy women; 2) women with depression &/or anxiety disorders; 3) women with irritable bowel syndrome (IBS); and, 4) women with both depression &/or anxiety and IBS.”

This is the first project worldwide to compare the human bacterial and physiological profiles of healthy adults, adults with depression &/or anxiety disorders, adults with IBS, and adults with comorbid depression &/or anxiety and IBS.

Please note, if you do not fit into one of these groups, are excluded from participation due to not meeting the eligibility criteria, or would simply prefer not to take part in all components, you will likely be eligible for the questionnaire-only sub-study, investigating associations between diet, and physical and mental health. Click on the 'Am I Eligible' tab above to find out more.