Digestion of fat: the role of bile salts and dietary fibres, short stories of colloids and polymers

In this talk, I will share my recent ventures into the world of food science from a colloid perspective, in particular stories of surfactants (specifically: bile salts, unusual biosurfactants that play a major role in lipid digestion) and polymers (specifically: those we call “dietary fibres”, usually polysaccharides that lower plasma cholesterol levels).

I will discuss how we have characterised bile salts (BS) adsorption using interfacial techniques, including neutron reflectometry,1 their interaction with fat droplets in emulsions stabilised by methylcellulose (a well-known dietary fibre and food emulsifier),2 the morphology of BS micelles, and their interactions with liposomes (as a mimic of the lipid nanostructures found in the gastrointestinal tract), using small-angle neutron scattering (SANS) and MD simulations.3 Understanding all these very “colloid-y” processes is key to the rational design of functional foods that can control lipid uptake and help address the current obesity crisis and associated cardiometabolic diseases.

Research interests. My research explores the structure and properties of soft matter, with a focus on neutron scattering techniques and rheology, in particular: hydrogels,4,5 polymeric micelles,6 and supramolecular structures formed by host-guest complexation with cyclodextrins.6,7

References

[1] Pabois et al. (2019) Molecular insights into the behaviour of bile salts at interfaces: a key to their role in lipid digestion J. Colloid Interface Sci., 556, 266-277.

[2] Pabois et al., (2020) Interactions of bile salts with a dietary fibre, methylcellulose and impact on lipolysis. Carbohydrate Polymers, 115741

[3] Pabois et al. (2021) Morphology of bile salts micelles and mixed micelles with lipolysis products, from scattering techniques and atomistic simulations J. Colloid Interface Sci. 587, 522-537 [4] Dreiss (2020) Hydrogel design strategies for drug delivery Curr. Opinion Colloid Interface Sci. 48, 1-17

[5] Zoratto et al. (2019) Supramolecular gels of cholesterol-modified gellan gum with disc-like and wormlike micelles, J. Colloid Interface Sci., 556, 301-312

[6] Puig-Rigall et al. (2019) Pseudo-polyrotaxanes of cyclodextrins with direct and reverse X-shaped block-copolymers: a kinetic and structural study, Macromolecules, 52, 1458-1468

[7] Serres-Gómez et al. (2018) Supramolecular hybrid structures and gels from host-guest interactions between b-cyclodextrin and PEGylated organosilica nanoparticles, Langmuir, 34, 10591-10602