**6. Acknowledgements**

The authors would like to thank Hans J.M. Swarts (Dept Animal Sciences, Wageningen University) for expert technical assistance and Prof Victor M. Wiegant (Dept Pharmacology, Med Fac, Utrecht University Medical Centre) for critically reviewing earlier versions of the manuscript. Current affiliations of the authors are: Danone Research, Centre for Specialised Nutrition, Singapore (EMvdB) and Wageningen, the Netherlands (BJMvdH); Notox B.V., Den Bosch, The Netherlands (HHvV) and Dept. Anatomy, Radboud University Nijmegen Medical Centre, the Netherlands (ANS-F).
