Determination of the prebiotic activity of wheat arabinogalactan peptide (AGP) using batch culture fermentation

Abstract

Purpose To test the prebiotic activity of wheat arabinogalactan-peptide (AGP), which is a soluble dietary fibre composed of arabinogalactan polysaccharide linked to a 15-residue peptide, which accounts for up to 0.4% of the dry weight of wheat flour. Methods The prebiotic activity of AGP prepared from white wheat flour was tested using in vitro fermentation by colonic bacteria in automated pH-controlled anaerobic stirred batch cultures and compared to fructooligosaccharide (FOS) and wheat flour arabinoxylan (AX). Bacterial populations were measured using fluorescence in situ hybridisation (flow-FISH) and short chain fatty acid (SCFA) concentrations were measured using HPLC. Results Fermentation of AGP resulted in a significant bifidogenic activity and increased concentrations of SCFAs, mainly acetate after 24 h of fermentation. Conclusions These results were comparable to those obtained with AX and confirm the prebiotic potential of AGP. Furthermore, fermentation of a mixture of AGP and AX was faster compared to the single substrates and more similar to FOS, indicating that combinations of fermentable carbohydrates with different structures are potentially more effective as prebiotics than single substrates.

Historical changes in the contents and compositions of fibre components and polar metabolites in white wheat flour

“…AGP is a short (15 amino acid) peptide which is o-glycosylated, probably on three hydroxyproline residues 20 . It accounts for about 0.4% of white flour 21 and is readily fermented by faecal bacteria in vitro 22 , indicating that it may have prebiotic properties in vivo. The concentration shown in Fig.…”

The role of bread in the UK diet: An update

“…While fructans and galactans are generally accepted as prebiotics, several other fibre types present in wheat including resistant starch, arabinoxylan‐oligosaccharide and arabinogalactan‐peptide have been described as ‘candidate’ prebiotics as these compounds have demonstrated prebiotic potential in vitro or in animal studies and data from human studies is emerging (Damen et al 2012; Lockyer & Nugent 2017; Lockyer & Stanner 2019; Harris et al 2020).…”

Dynamic Multi-Stage Gastrointestinal Digestion Model Assessment of Microbial Fermentation Products of Collagen Hydrolysates

“…In contrast to the present work, the latter study did not include stomach and small intestine digestive processes that can modify peptide profiles prior to their exposure to microbial metabolism. Other reports have shown that wheat arabinogalactan peptides were associated with an increase in SCFAs after 24 h, although this was assessed using in vitro batch fermentation rather than a dynamic GI model system [43]. The multistage dynamic GI model can provide a more accurate representation of human digestive and microbiota metabolism of dietary components as compared to either static digestion models or animal models [49,50].…”

“…Two separate digestion runs were completed for each treatment, with a washout/re-stabilization period of 3 days between treatments. Previous in vitro fermentation experiments have also utilized two separate digestion runs [43].…”