Assessment of in vitro digestion of reduced sugar biscuits with extruded brewers’ spent grain

•The Extruded Brewers’ Spent Grain (EBSG) provided resistant starch to biscuits.•Biscuits with EBSG showed reduced glucose bioaccessibility and absorption.•Biscuits with EBSG presented increased bioaccessibility of phenolic acids.•FOS addition caused increased butyric acid production by colonic fermentation.•EBSG fermentation released short chain fatty acids able to reduce risk of diseases.