Bile conjugation and its effect on in vitro lipolysis of emulsions

Abstract

Bile Salts (BS) are responsible for stimulating lipid digestion in our organism. Gut microbiota are responsible for the deconjugation process of primary conjugated to secondary unconjugated BS. We use two structurally distinct BS and characterize the rate of lipolysis as a compound parameter. A static in-vitro digestion model as well as meta-analysis of literature data has been performed to determine the most influential factors affecting the lipid digestion process. The results demonstrate that lipolysis of emulsions using conjugated BS (NaTC, FFA = 60.0 %, CMC in SIF = 5.58 mM, MSR of linoleic acid = 0.21, rate of adsorption = -0.057 mN/m.s) enhances the release of FFA compared to deconjugated BS (NaDC, FFA = 49.5 %, CMC in SIF = 2.49 mM, MSR of linoleic acid = 0.16 rate of adsorption = -0.064 mN/m.s). These results indicate that conjugation plays an important role in controlling the rate of lipolysis in our organism which can be in turn, tuned by the microflora composition of our gut, ultimately controlling the rate of deconjugation of the BS.

Keywords: Adsorption; Bile salts; Desorption; Emulsion; In-vitro digestion; Interfacial tension; Lipids; Lipolysis.