The present invention relates to extracts from Fraxinus angustifolia samara, processes for providing such extracts, and methods and uses of the extracts obtained. In particular, the present invention relates to the use of such extracts in reversing obesity-related and/or metabolic syndrome-related gut microbiota dysbiosis treatment, treating or preventing hepatic steatosis, non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH), and modulating and/or adjusting gut microbiota.