The dynamic, postprandial response of the human organism to acute ingestion of food is a key element of nutritional sciences as it directly associates food with its impact on human metabolism. The study of this response can thus facilitate sensitive characterization of the metabolic impact of foods that are similar but which differ in compositional or structural features. The relevance of the postprandial analysis strategy to nutritional sciences can be potentiated by (i) complementing classical biochemical analyses with ‘omic` methods, such as metabolomics and transcriptomics, using blood as a reporter of the metabolic activity of the organism; (ii) conducting metabolomic analyses on foods and linking the results of these analyses to the postprandial response of subjects who ingest the food under investigation.
One important determinant of the variability in the metabolic response of the human organism to the ingestion of food is the gut microbiota, a significant fraction of the human metabolome being derived from gut microbial activity. In this context, the technological process of food fermentation by microorganisms provides an ex vivo method to modulate the postprandial response of the organism by predigesting food (`preprandial digestion`).
The concepts exposed above are illustrated by presenting data from two human intervention studies that evaluated the postprandial responses to different dairy products (milk, yoghurt and cheese) in which the properties of the foods were modified by bacterial fermentation. The molecular and functional blood markers that were associated with the different foods evaluated in these studies are presented, including metabolites derived from bacterial metabolism and genes involved in metabolic pathways such as oxidative phosphorylation and inflammation.
The integrated use of these markers may help to strengthen the evidence for an association between metabolic health and food qualities, consequently narrowing the gap between food and nutritional sciences.