The immunological consequences of pasteurisation: Comparison of the response of human intestinally-derived cells to raw versus pasteurised milk

Microarray technology was used to identify differentially expressed biological signatures in human intestinal cell line (HT-29) exposed to raw versus pasteurised milk; 1041 differentially expressed genes (≥1.3 fold change) were identified (P < 0.001) between exposure groups. These were further identified to be contained within 179 gene ontologies. Genes more highly expressed (599 or 57.5%) in cells exposed to raw milk were predominately contained within immune-based gene ontologies. In contrast, genes showing lower expression in raw milk treated cells (442 or 42.5%) in comparison with pasteurised milk were involved in a broader range of cellular functions. The lowered immune function identified in cells exposed to pasteurised milk was intriguing and suggests that raw milk may be capable of inducing certain aspects of the immune system, including processes involved in T and B cell function/development. The results may indicate an alteration in the immunomodulatory potential of milk following pasteurisation.