Development of dietary soluble fibres by enzymatic synthesis and assessment of their digestibility in in vitro, animal and randomised clinical trial models

Abstract

The aim was to develop novel fibres by enzymatic synthesis, to determine their total dietary fibre by AOAC method 2009.01 and to estimate their potential digestibility and assess their digestibility in vivo using glycaemic and insulinaemic responses as markers in mice and randomised clinical trial models. We found that fibre candidates to which α-(1,2) branching was added were resistant to digestion in the mouse model, depending on the amount of branching. These results show that in vivo models are needed to reliably assess the digestibility of α-glycosidic-linked oligomeric dietary fibre candidates, possibly due to absence of brush border α-glucosidase activity in the current in vitro assessment. α-(1,3)-linked and α-(1,6)-linked glucose oligomers were completely digested in humans and mice. In conclusion, it is possible to develop dietary soluble fibres by enzymatic synthesis. Adding α-(1,2) branching increases their resistance to digestion in vivo and can thus improve their suitability as potential fibre candidates.

Clinical Trial Registry: ClinicalTrials.gov, NCT02701270

Keywords:

• Digestibility
• glycaemia
• insulinaemia
• soluble fibre

Acknowledgements

All authors were employees of DuPont during the study and declare no other conflicts of interest. O.H. coordinated the study. R.D., Z.Y., Q.C., S.C.R., S.S., Z.C.B., B.M.R., K.D.R.-J., J.P.L., R.E.H., M.L.M. and A.D.K. developed the fibre candidates and performed the digestibility in vitro. A.C.O. and S.D.F. designed and conducted the simulations in vitro. P.M., J.M.C.R., Y.P.D. and J.R.D. designed and performed the mouse experiments. K.T. and A.I. coordinated the clinical trial. All authors participated in the preparation and revision of the manuscript and gratefully acknowledge help from the personnel of E.I. DuPont de Nemours & Co. and Leatherhead Food Research Ltd.

Disclosure statement

The study was fully sponsored by E.I. DuPont de Nemours & Co. The authors alone are responsible for the content and writing of this article.