Dairy Foods: Probiotics, Bioactives, and Health

摘要

The assortment of polar lipids that constitute the milk fat globule membrane(MFGM) affects infant gastrointestinal development and one ofthe possible mechanism might be via bacteria-lipid interaction that inturn affect the gut microbiome. However, there is scarce informationabout this topic. In our research group, we have proven that differentlactic acid bacteria (LAB) bind and utilize different mixtures of MFGMphospholipids. Based on this information, we hypothesized that probioticLAB modify their adherence properties when MFGM phospholipids arepresent during cell growth. To test this, we performed surface bindingstudies of bacterial cells grown in a defined medium (control), and withadded MFGM phospholipids (0.5% wt/vol). We used a quartz crystalmicrobalance with dissipation (QCM-D) approach to measure bindingkinetics. Our results show that the addition of MFGM during bacterialgrowth greatly alters the adherence properties to gold surfaces and moreimportantly, to intestinal cells as well. We calculated the affinity of thebacterial cells, via the total mass adsorbed, and were able to determinebiochemical parameters such as the affinity constants (K_d) and foundthat L. casei and L. reuteri grown in MFGM increased significantly theirbasal binding affinity whereas the opposite effect was observed in cellsof P. acidilactici, L. plantarum and L. delbrueckii. Interestingly, it wasobserved that regardless of the basal adherence properties, bacterialcells grown in MFGM, except for L. plantarum, displayed an unusualaffinity toward intestinal cells characterized by such a strong bindingaffinity, that they are detached from the gold scaffold surface. Furtherexperiments are needed to understand this interaction but based inour results, it is evident that in the presence of MFGM phospholipids,probiotic cells are subjected to metabolic changes or conditioning tosurface attachment, which modify their binding properties having animpact in the gastrointestinal environment.