Lipid structures in foods as key players in nutrition and health: from milk fat globules to polar lipids and beyond

This lecture will take you through my fascinating journey in exploring dietary lipids from food science to nutrition and metabolism. After characterizing the physico-chemical structures of milk fat globules and how they are modified by dairy processes, I was eager to find out how this could impact the fat digestion, intestinal absorption and further metabolic impacts of ingested fatty acids. Enphasizing translational research that benefits both human health and industrial innovation, I fostered multidisciplinary collaborations with food scientists, fundamental metabolic scientists, biochemists and clinical human nutrition scientists. Together, we introduced the concept of "fast vs slow fat" in humans, revealing that fat/oil emulsification enhances intestinal absorption, leading to a quicker rise and clearance of postprandial lipemia. This phenomenon also increases total exogenous fatty acid beta-oxidation in both normal-weight and obese individuals compared to bulk fat, offering new nutritional strategies for managing postprandial cardiometabolic risk factors. Our investigations further demonstrated that the intestinal absorption of dietary fatty acids coincides with the co-absorption of proinflammatory lipopolysaccharides from the gut microbiota. This mechanism is now recognized as a significant contributor to metabolic inflammation, prompting the development of nutrition strategies to tackle this phenomenon. Over the past decade, we demonstrated the metabolic benefits of polar lipids, compared to the major fatty acid sources that are triglycerides. We were able to translate several of our preclinical findings to humans, demonstrating the benefits of the polar lipids of the milk fat globule membrane on reducing lipid markers of cardiovascular risk. We further identified mechanisms involving milk sphingolipid residues acting in the gut and interacting with the gut microbiota. This lecture will discuss the implications of our findings for cardiometabolic health, industrial developments, and explore new perspectives related to plant polar lipids and the food matrix concept, providing an overview of the evolving landscape in this field.