DAG4 is one of Lifelines' additional assessments performed in collaboration with the UMCG department of genetics (see also: DAG1, DAG2 and DAG3). DAG is the abbreviation of DArmGezondheid, or “Gastrointestinal health” in Dutch.

There is increasing insight into the role of bacterial composition in the intestine and upon the occurrence of (chronic) diseases. Previous research in DAG1 (DEEP) demonstrated the relation of the microbiome and lipids, but also many other diseases and intrinsic and extrinsic factors. Previous research in DAG3 (DAG3) described the gut microbioom in a larger cohort.

Longitudinal analyses in 350 Lifelines DEEP participants that were also part of the DAG3 collection, showed that microbiome individual specific patterns could be stable for >3 years. However, it was also observed that some microbial changes were related to individual’s changes over time were in line with individual’s changes in their healthy status, lifestyle and medication usage (REFERENCE).

The purpose of DAG4 was to extent the amount of participants with longitudinal data and longitudinal biological samples, that gives an unique opportunity to study the long-term dynamics of the gut microbiome and its relation to developing and progressing of diseases and phenotypes.