SU42 - DISCOVERY AND REPLICATION STUDIES FOR MICROBIOTA SIGNATURES IN MAJOR DEPRESSIVE DISORDER.

Growing evidence suggests the link between gut microbiota and mood regulation. While previous studies reported several microbiota targets for Major Depressive Disorder (MDD), the influence of dietary patterns is not considered. The current study aims to identify microbiota targets for MDD depression in two independent Taiwanese datasets while taking nutrient elements into consideration. We separately analyzed fecal samples from two independent datasets. The discovery set consisted of 9 MDD patients and 11 healthy controls while replication set comprised of 15 MDD patients and 25 healthy controls. Illumina Miniseq or Miseq platform were applied for 16 s rRNA sequencing. We further assessed food frequency questionnaires and Beck depression inventory to obtain the information of nutrients and depressive status. We applied linear discriminant analysis effect size (LEfSe) to test associations between depression and microbiota and adjusted for nutrient status. In the discovery data, the microbiota exhibited significant group differences in genus level, including increased abundance of Bilophila and Gillisia, and decreased abundance of Clostridium. The results remained significant after adjusted levels of carbohydrates, protein and fat intake. The replication study is underway. Our results revealed novel targets to be associated with depression and are independent of dietary influences. These results awaiting replication and further validation for depression. [ABSTRACT FROM AUTHOR]