COVID-19 studies are our top priority. For all other trials, there is a 4-week delay in processing a trial submitted to the ANZCTR and additional delays for updates of registered trials. We appreciate your patience.

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been endorsed by the ANZCTR. Before participating in a study, talk to your health care provider and refer to this information for consumers
Trial registered on ANZCTR


Registration number
ACTRN12618000432213
Ethics application status
Approved
Date submitted
26/02/2018
Date registered
26/03/2018
Date last updated
26/03/2018
Type of registration
Retrospectively registered

Titles & IDs
Public title
The gut microbiome: a new pathway to obesity prevention and metabolic health
Scientific title
The gut microbiome: a new pathway to obesity prevention and metabolic health
Secondary ID [1] 289405 0
None
Universal Trial Number (UTN)
U1111-1184-0829
Trial acronym
PROMIsE (PRedictors linking Obesity and the MIcrobiomE) Study
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Obesity 299072 0
Metabolic Health 306845 0
Condition category
Condition code
Diet and Nutrition 299108 299108 0 0
Obesity
Metabolic and Endocrine 306223 306223 0 0
Normal metabolism and endocrine development and function

Intervention/exposure
Study type
Observational
Patient registry
False
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
We will conduct a cross sectional study in 136 Pacific women (known high risk of obesity, 68% obesity) and 136 NZ European women (known moderate risk of obesity, 28% obesity). Women will be selected such that half in each group will have a normal body fat profile (BMI=18.5 -24.9kg/m2) and half an obese body fat profile (BMI>=30 kg/m2). We will characterise the gut microbiome in all groups and test whether taste perception, diet, sleep and physical activity are key pathways that modify the gut microbiome and its impact on obesity.
Intervention code [1] 294991 0
Not applicable
Comparator / control treatment
Not applicable
Control group
Uncontrolled

Outcomes
Primary outcome [1] 298581 0
Dietary intake and eating behaviour as assessed by 5-day estimated food record, Food Frequency Questionnaire (FFQ), Dietary Diversity Questionnaire (DDQ), Three-Factor Eating Questionnaire (TFEQ) and Eating Attitudes Test (EAT-26).

Timepoint [1] 298581 0
Cross-sectional study - one-time measures
Primary outcome [2] 304980 0
Body composition and body fat profile as assessed by International Society for the Advancement of Kinanthropometry (ISAK) protocol, Bioelectrical Impedance Analysis (BIA), Dual-energy X-ray Absorptiometry (DXA) and Sagittal Abdominal Diameter (SAD).
Timepoint [2] 304980 0
Cross-sectional study - one-time measures
Primary outcome [3] 304981 0
Gut microbiome complexity and functionality as assessed by shotgun-sequencing.
Timepoint [3] 304981 0
Cross-sectional study - one-time measures
Secondary outcome [1] 324621 0
Intensity and hedonic liking of taste perception (sweet, bitter, fat) as measured by general labelled magnitude scales (gLMS).
Timepoint [1] 324621 0
Cross-sectional study - one-time measures
Secondary outcome [2] 343956 0
Sleep as assessed by wrist worn AW2 actiwatch actigraph, 7-day sleep diary, Pittsburgh Sleep Quality Index (PSQI), Munich ChronoType Questionnaire (MCTQ) and Berlin Questionnaire.
Timepoint [2] 343956 0
Cross-sectional study - one-time measures
Secondary outcome [3] 343959 0
Physical activity as assessed by w-GT3X triaxial accelerometer, 7-day physical activity diary and Recent Physical Activity Questionnaire (RPAQ).
Timepoint [3] 343959 0
Cross-sectional study - one time measures
Secondary outcome [4] 343961 0
Blood metabolic biomarkers (plasma glucose, insulin, HbA1c, lipids), inflammation markers (hs-CRP, IL-6, TNFa) and endocrine regulators (GLP-1, ghrelin, leptin) as assessed by Roche/Hitachi Cobas auto-analyser and multiplex assays.
Timepoint [4] 343961 0
Cross-sectional study - one time measures

Eligibility
Key inclusion criteria
1. Provision of written informed consent
2. Willingness to comply with study requirements
3. Female 18-45 years of age, of NZ European or Pacific ethnicity with BMI between 18.5 and 24.9kg/m2 or of BMI greater than or equal to 30kg/m2
4. Generally healthy, no chronic health conditions
Minimum age
18 Years
Maximum age
45 Years
Gender
Females
Can healthy volunteers participate?
Yes
Key exclusion criteria
1. Had bariatric surgery
2 Taking medications affecting the immune system or for any chronic disease
3. Pregnant or breastfeeding an infant less than 6 months of age
4. Chronic illnesses (eg. Diabetes Mellitus, CVD, etc)
5. Allergic to milk
6 Severe dietary restrictions or avoidances
7 Unable to comply with study protocol requirements

Study design
Purpose
Natural history
Duration
Cross-sectional
Selection
Defined population
Timing
Both
Statistical methods / analysis
We have based our sample size calculations on metagenome-based measures of gene richness (gene counts) of faecal microbial communities which categorise individuals into clusters of high or low gene count. Individuals in the low gene count cluster may be at increased risk of progressing to obesity-associated co-morbidities. All power calculations are based on analyses for each ethnic group separately, as differences in associations between ethnic groups may exist.

Descriptive statistical methods will be used to summarise gut microbiome complexity and functionality, dietary intake and behaviour, sweet and fat taste perception, sleep, physical activity and blood biomarkers. We will first analyse the differential gut microbiome complexity and gene richness between obese body fat profile women and normal body fat profile women stratified by ethnicity using linear regression analyses. We will also assess associations between gut microbiome complexity and functionality and biological and behavioural factors described above. In addition to analysing the gut microbiome complexity and gene richness as a continuous variable, we will also stratify participants into groups with reduced versus high gut microbiome complexity and gene richness, based on the observed differences between groups using cut points employed in previous studies. For this, we will use logistic regression analyses. We will conduct multiple regression analyses to assess the independent effects of the biological and behavioural factors described above and perform stratified analyses to assess effect modification (or interactions). All analyses will initially be stratified by ethnicity. If no differences in associations between ethnic groups are observed, we will combine the groups for analyses. All analyses will be adjusted for potential confounders (e.g. socio-economic position, age).

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment outside Australia
Country [1] 7946 0
New Zealand
State/province [1] 7946 0
Auckland area

Funding & Sponsors
Funding source category [1] 293778 0
Government body
Name [1] 293778 0
Health Research Council of New Zealand
Address [1] 293778 0
50 Grafton Road, Grafton, Auckland 1010
Country [1] 293778 0
New Zealand
Primary sponsor type
Individual
Name
Professor Bernhard Breier (Chair in Human Nutrition)
Address
Private Bag 102904 (Massey University)
North Shore
Auckland 0745
Country
New Zealand
Secondary sponsor category [1] 298246 0
Individual
Name [1] 298246 0
Associate Professor Rozanne Kruger (Associate Professor in Dietetics and Human Nutrition)
Address [1] 298246 0
Private Bag 102904 (Massey University)
North Shore
Auckland 0745
Country [1] 298246 0
New Zealand

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 295217 0
Health and Disability Ethics Committees (Southern Committee)
Ethics committee address [1] 295217 0
Ministry of Health
Freyberg Building
20 Aitken Street
PO Box 5013
Wellington 6011
Ethics committee country [1] 295217 0
New Zealand
Date submitted for ethics approval [1] 295217 0
21/03/2016
Approval date [1] 295217 0
30/03/2016
Ethics approval number [1] 295217 0
16/STH/32

Summary
Brief summary
The prevalence of obesity has increased substantially over recent decades and interventions to halt the epidemic have been unsuccessful. Although the causes of obesity are complex, key drivers include the overconsumption of highly palatable energy-dense and nutrient-poor foods. These dietary changes have had a profound impact on our gut microbiome, which comprises the bacterial community of the bowel. Exciting new evidence suggests that microbial complexity and functionality in the gut may play a crucial role in obesity. In the proposed study we will characterise the gut microbiome in two populations with markedly different metabolic disease risk (Pacific and European women) and different body fat profiles (normal and obese). We will test whether taste perception, diet, sleep and physical activity are key pathways that modify the gut microbiome and its impact on obesity. This new knowledge will help us understand obesity and how best to prevent it.?
Trial website
www.massey.ac.nz/promise
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 66554 0
Prof Bernhard Breier
Address 66554 0
Private Bag 102904 (Massey University)
North Shore
Auckland 0745
Country 66554 0
New Zealand
Phone 66554 0
+64 9 2136652
Fax 66554 0
Email 66554 0
b.breier@massey.ac.nz
Contact person for public queries
Name 66555 0
Prof Bernhard Breier
Address 66555 0
Private Bag 102904 (Massey University)
North Shore
Auckland 0745
Country 66555 0
New Zealand
Phone 66555 0
+64 9 2136652
Fax 66555 0
Email 66555 0
b.breier@massey.ac.nz
Contact person for scientific queries
Name 66556 0
Prof Bernhard Breier
Address 66556 0
Private Bag 102904 (Massey University)
North Shore
Auckland 0745
Country 66556 0
New Zealand
Phone 66556 0
+64 9 2136652
Fax 66556 0
Email 66556 0
b.breier@massey.ac.nz

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary