International scientists use genomics to unwrap the goodness of milk
By Jennifer Giambroni
The science of milk, lactation, nutrition and genetics came together this September at the 3rd International Symposium on Milk Genomics and Human Health in Brussels, Belgium. The three-day event, organized by the California Dairy Research Foundation (CDRF) and the International Dairy Federation (IDF), featured current developments in research utilizing the tools of genomics to understand milk and its health properties.
Presented by the International Milk Genomics Consortium (IMGC), the annual event is based on the scientific principle that milk is the only biological product that is the direct result of continuous Darwinian selective pressure to provide nutrition and improve the health of mammals. Lactation evolved over millions of years to produce ingredients that provide infants with a greater probability of health and survival. The critical biological strategies that emerged from this evolutionary process are encoded within the genomes of mammals.
The field of genomics provides new opportunities to understand the role each component of milk plays in overall health by studying its genetic origins. Bruce German, a professor at the University of California, Davis (UC Davis), and scientific chair of the IMGC, said, “With the human genome sequenced and many other genomes following, the genes responsible for milk production can guide scientific research into the molecules, functions and health benefits contained in milk’s diverse components.”
The first milk genomics symposium in 2004 focused on the study of lactation genomics for nutrition. The second event provided a pathway to move forward as a global consortium. This year’s event concentrated on recent scientific breakthroughs and created a strategic direction for moving these into practice.
Symposium presentations included results obtained by analyzing the oligosaccharides present in human milk and their selective stimulation of specific intestinal bacteria. Carlito Lebrilla, a professor at UC Davis, presented state-of-the-art mass spectrometry and how these new analytical techniques can revolutionize the understanding of the structures of milk oligosaccharides. Analytical strategies have been developed to quantify these molecules in complex mixtures making it possible to rapidly define many of their biological functions.
UC Davis Professor David Mills stated that most bacteria, including intestinal pathogens, are unable to use these complex sugar structures as food sources; however, bifidobacteria infantis, a strain obtained from a breast-fed infant, grew successfully solely on these molecules as a carbon source (see related genomics article on page 7).
Kevin Nicholas of the University of Melbourne conducted research on a wide variety of mammals and marsupials identifying alpha lactalbumin as a potential apoptotic regulator during involution of mammary tissue. Catharina Svanborg of Lund University in Sweden presented research on the ability of an intermediate of alpha lactalbumin, HAMLET, to promote the death of transformed cells culminating in a demonstration of the elimination of tumor cells in bladder cancer in humans. Clemens Kunz of Germany’s Giessen University provided a summary of human and animal milk oligosaccarides focusing on potential influence of specific oligosaccharide patterns within the intestinal tract.
Itamar Barash of the Volcani Center in Israel, discussed the regulation of milk protein in the mammary gland; Patrice Martin of the Institut National de la Recherche Agronomique (INRA) in France demonstrated how genetic polymorphisms may modulate the protein fraction of milk by affecting different cellular processes; Daniel Tomé of the INRA described how a modification of milk protein composition could improve their effect on energy metabolism; Pasquali Ferranti of the University of Napoli in Italy spoke about milk genomics and proteomics; Sylvain Bellier of the INRA highlighted an integrative approach to using genomics and proteomics to identify intestinotrophic properties in the milk of mice; Kay-Uwe Wagner of the University of Nebraska Medical Center focused on the transcriptional control of normal mammary function; and Johan van Arendonk of the Wageningen Institute of Animal Sciences presented information from the Dutch Milk Genomic Initiative, which is working to identify genes that contribute to natural genetic variation in milk quality traits—milkfat and milk protein composition.
The Symposium also spotlighted the importance of IMGC’s Web Portal (www.imgconsortium.org) as the interface through which scientists can work with databanks that are becoming the standard information resource of modern life science. Event sponsors included CNEIL, DairyAustralia, Dairy Farmers of Canada, MeadJohnson Nutritionals, The Dutch Dairy Association and Teagasc. The symposium attracted attendance from 24 countries, including Australia, Belgium, Canada, Denmark, France, Germany, Hungary, Ireland, Italy, The Netherlands, New Zealand and the U.S.
A fourth International Symposium on Milk Genomics & Human Health is scheduled for November 7-9, 2007, in Napa, CA, and will be coordinated by the CDRF. Details will be available online in late 2006. For more information, contact coordinator Jennifer Giambroni at (415) 254-4549, or info@imgconsortium.org.
