JMIR Publications

ABSTRACT

Background:

The human intestinal microbiome serves as an essential mediator between nutrition and host health. Despite growing interest in this connection, only few associations between microbiome, nutrition and health have been clearly established. Available studies paint an inconsistent picture, in part owing to a lack of standardization. Besides, for the assessment of reliable representative dietary intake data, e.g., by national nutritional monitoring, standardized and validated tools that are up-to-date with recent developments of food products and nutritional behaviour of the population are pivotal.

Objective:

The ErNst Study (‚Erfassung der Energie- und Nährstoffzufuhr‘, engl. ‚assessment of energy and nutrient intake’) was conceived to address two objectives. Firstly, to verify whether, by means of the current version of the dietary recall software GloboDiet, food consumption as well as energy and nutrient intake of the German population can be recorded validly for the German National Nutrition Monitoring. And secondly, to obtain high quality data using standardized methods on the microbiome, combined with dietary intake data and additional fecal sample material to also assess the functional activity of the microbiome by measuring microbial metabolites.

Methods:

Healthy female and male volunteers aged between 18 and 79 years were recruited. Anthropometric measurements included body height and weight, body mass index and bioelectric impedance analysis (BIA). Current food consumption was assessed one 24-h recall using the GloboDiet software and habitual diet was determined using a food frequency questionnaire (FFQ) for a period of 30 days. Urine was collected over 24 h and potassium, sodium, nitrogen and creatinine concentrations and osmolality were measured. Stool samples were collected in duplicate for a single timepoint and immediately frozen. DNA was isolated from stool samples and amplified with primers targeting the 16S rRNA gene for high throughput sequencing and determination of the microbiome composition. Physical activity was measured over a period of at least 24 h using a wearable accelerometer.

Results:

Recruitment resulted in the inclusion of 117 participants that were equally distributed between the sexes and three age groups (18 – 39, 40 – 59, 60 – 79 years). Stool samples for microbiome analysis were successfully collected from 106 participants with accompanying habitual diet data (30-d FFQ). Current diet data and 24-h urine samples were collected from 109 participants, of which physical activity was measured for 82 cases.

Conclusions:

We completed recruitment and sample collection of the ErNst study with a high degree of standardization. The generated samples and data will be used to validate the GloboDiet software for the German National Nutrition Monitoring and to compare microbiome composition and nutritional patterns. Metabolite concentrations will additionally be measured for stool and urine samples to investigate functional associations and potential biomarkers. Clinical Trial: Registrationnumber by DRKS (german register of clinical studies): DRKS00015216 (at 01.10.2018) Universal Trial Number (UTN) by WHO: U1111-1218-3862