A dialysis membrane process for the in vitro simulation of bile acids absorption in the small intestine

Accounting for the complexity of the human digestion process remains a challenge for in vitro digestion (IVD) model systems, with the absorption of bile acids (BAs) being among the greatest challenges. This study aimed to develop an online dialysis membrane process utilizing hollow fiber membranes for mimicking the intestinal absorption of BAs. Different flow rates were examined, to determine the most optimal for the highest reduction of BAs. The obtained knowledge facilitated the identification of the governing principles of BA absorption, i.e., (i) the catalytic activity of pancreatin in releasing BAs from the food matrix, (ii) the mass transfer of BAs through the membrane, due to diffusion and convective transport (iii) the water removal from digesta. This study offers an open-source, simple and reproducible dialysis system able to simulate BAs' absorption during the IVD of an emulsified food model system in a realistic timeframe, unlike other IVD systems implementing dialysis.