Abstract #T46

# T46
Effect of milk fat globule membrane phospholipids in the adherence of probiotic lactic acid bacteria—Modelling interactions in the human gut.
J. Ortega-Anaya*1, D. Rocha-Mendoza1, I. Garcia-Cano1, R. Jimenez-Flores1, 1The Ohio State University, Columbus, OH.

The assortment of polar lipids that constitute the milk fat globule membrane (MFGM) affects infant gastrointestinal development and one of the possible mechanism might be via bacteria-lipid interaction that in turn affect the gut microbiome. However, there is scarce information about this topic. In our research group, we have proven that different lactic acid bacteria (LAB) bind and utilize different mixtures of MFGM phospholipids. Based on this information, we hypothesized that probiotic LAB modify their adherence properties when MFGM phospholipids are present during cell growth. To test this, we performed surface binding studies of bacterial cells grown in a defined medium (control), and with added MFGM phospholipids (0.5% wt/vol). We used a quartz crystal microbalance with dissipation (QCM-D) approach to measure binding kinetics. Our results show that the addition of MFGM during bacterial growth greatly alters the adherence properties to gold surfaces and more importantly, to intestinal cells as well. We calculated the affinity of the bacterial cells, via the total mass adsorbed, and were able to determine biochemical parameters such as the affinity constants (Kd) and found that L. casei and L. reuteri grown in MFGM increased significantly their basal binding affinity whereas the opposite effect was observed in cells of P. acidilactici, L. plantarum and L. delbrueckii. Interestingly, it was observed that regardless of the basal adherence properties, bacterial cells grown in MFGM, except for L. plantarum, displayed an unusual affinity toward intestinal cells characterized by such a strong binding affinity, that they are detached from the gold scaffold surface. Further experiments are needed to understand this interaction but based in our results, it is evident that in the presence of MFGM phospholipids, probiotic cells are subjected to metabolic changes or conditioning to surface attachment, which modify their binding properties having an impact in the gastrointestinal environment.

Key Words: adherence studies, LAB and milk fat globule membrane (MFGM), intestinal cells