Dr Philip Smith, Digital and Education Editor of Gut and Honorary Consultant Gastroenterologist at the Royal Liverpool Hospital, Liverpool, UK interviews Professor Fredrik Bäckhed, The Wallenberg Laboratory, Department of Molecular and Clinical Medicine, University of Gothenburg, Gothenburg, Sweden on the paper '6α-hydroxylated bile acids mediate TGR5 signalling to improve glucose metabolism upon dietary fiber supplementation in mice' published in paper copy in Gut in February 2023, and available online: https://gut.bmj.com/content/72/2/314