Bugs and Brains: The Gut and Mental Health Study

There is growing interest in the link between the human microbiome (i.e., bacteria that live in our bodies) and human health. The Bugs and Brains Study is aiming to better understand the role of the microbiome, particularly in relation to some common mental and physical health conditions. We are also interested in learning about how the microbiome is related to biological functions (such as levels of hormones and inflammation), stress, and wellbeing. Please click on the Background tab for detailed background information about the study.

Participation in the Bugs and Brains Study involves the completion of online questionnaires, an interview, and the collection of faecal, urine, saliva, and hair samples. Participants who do not meet the eligibility criteria for, or would prefer not to take part in, the biological samples, will be asked to complete the online questionnaires only.

The main aim of the Bugs and Brains Study is to compare the microbial and physiological profiles of four groups of people:

1. healthy adult women
2. women with depression &/or anxiety disorders (who are not currently taking anti-depressant or anti-anxiety medication),
3. women with irritable bowel syndrome (IBS), and
4. women with both depression &/or anxiety and IBS.

If you think you fit into one of these four groups, you may be eligible to participate in all components of the Bugs and Brains Study. If not, you may be eligible to participate in the questionnaire-only components of the study. Click on the 'Am I Eligible' tab above to find out more.

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.

The Bugs and Brains Study is made up of four phases; an online screening questionnaire, an interview, collection of biological samples, and further online questionnaires. These phases are briefly described below. You may be asked to participate in all, or only some, of these phases. If participating in the questionnaire-only sub study, you will only be asked to complete Phases 1 and 4.

For further details about what participation in the Bugs and Brains study involves, please read through the Plain Language Statement.

Listed below are a list of 8 items relating to some of the main selection criteria for participation in all components of the Bugs and Brains Study. If you answer ‘YES’ to all 8 items, you may be eligible for participation in all aspects of the study. If you answer 'NO' to some items, you may be eligible to complete the questionnaire-only components.

“If you answered ‘YES’ to being female, and are at least 18-years of age, you are eligible to participate in the questionnaire-only components of the study. If you answered ‘YES’ to all the items, you may be eligible to participate in all aspects of the study.

If you would like to take part, or would like to discuss your potential eligibility with a member of our team, please click here to provide us with your contact details. We will send you some information about the study, and a member of our team will give you a call to discuss what participation involves and answer any questions.

If you are not eligible for the study (or prefer not to take part), but would like to receive updates and newsletters about the study, please click here to provide us with your contact details.