Controlling lipid delivery by tailored Oil/Water Interfaces

Abstract

Lipid emulsions (LE) gained increasing attention as their interfacial layer was found to be a potential modulator for human lipid digestion. This allows the production of LEs with specific gastric behavior, offering great potential for controlled lipid delivery and satiety control [1]. Within our studies we established a range of LEs with different interfacial layers. Here we focus on the unique in vitro and in vivo gastric behavior of LEs stabilized by nanocrystalline cellulose (NCC). No gastric lipase activity was detectable in vitro for NCC concentrations as low as 0.5 wt% (LEs with 5 wt% MCT-oil). We concluded that NCC efficiently forms a dense interfacial network able to block gastric lipase [2]. Mixing NCC-LEs with simulated gastric fluid induced the formation of a dense gel, wherein lipid droplets kept their original entity. Addition of pancreatic lipase resulted in a significantly slower fatty acid release compared to all other LEs. This gastric structuring of NCC-LEs was confirmed by a novel magnetic resonance imaging technique able to quantify lipids in the human stomach [3]. A viscous gel with uniform lipid distribution was observed for NCC, whereas other LEs underwent lipid dilution or layering. This unique gastric structuring and lipase blocking influenced hormone response in humans upon LE ingestion. Peak plasma concentrations of satiety mediating hormones were delayed and significantly lower as for other LEs. Due to the low digestibility of NCC-LEs a high hormonal response could have been expected due to the ileal break [4]. However, no such effect was observed. Our studies suggest that interfacial layers are a potential tool to modulate human lipid digestion. In particular, NCC offers large potential due to its unique behavior towards controlled lipid or drug delivery and satiety control. The widely postulated ileal break was not observed. References: 1) Golding, M., & Wooster, T. J. (2010). The influence of emulsion structure and stability on lipid digestion. Current Opinion in Colloid & Interface Science, 15(1), 90–101. http://doi.org/10.1016/j.cocis.2009.11.006 2) Scheuble, N., Lussi, M., Geue, T., Carrière, F., & Fischer, P. (2016). Blocking Gastric Lipase Adsorption and Displacement Processes with Viscoelastic Biopolymer Adsorption Layers. Biomacromolecules, 17(10), 3328–3337. http://doi.org/10.1021/acs.biomac.6b01081 3) Liu, D., Parker, H. L., Curcic, J., Schwizer, W., Fried, M., Kozerke, S., & Steingoetter, A. (2016). The visualisation and quantification of human gastrointestinal fat distribution with MRI: a randomised study in healthy subjects. British Journal of Nutrition, 115(5), 903–912. http://doi.org/10.1017/S0007114515005188 4) Maljaars, P. W. J., Peters, H. P. F., Mela, D. J., & Masclee, A. A. M. (2008). Ileal brake: A sensible food target for appetite control. A review. Physiology & Behavior, 95(3), 271–281. http://doi.org/10.1016/j.physbeh.2008.07.018