Nutritional Genomics

The beginning of nutritional genomics

Nutrigenomics:

Nutrigenomics is the characterization and sequencing of an organism' s genome and analysis of the relationship between gene activity and cell function Nutritional genomics, or food genomics is the specific application of genomics in research pertaining to agriculture, food processing and food consumption. It studies how food, genes and lifestyle interact.

Nutrigenomics covers the entire food chain. Agriculture use food genomics to increase vitality, disease resistance and drought and salt tolerance resulting in increase of yield, reduced loss during storage and transport, enriched micronutritions and microorganism producing auxiliary substances and food ingredients.

The knowledge of biological active components has been developed during the last ten years being the basis for the development of new functional foods, looking forward to tailored functional foods and personalized foods.

Genomics researche is arousing hope that food will be adaptable to individuals' genetic profiles. Genetic susceptibility to disease ranging from intestinal cancer to food infection. Genomics researche is helping to map these phenomena and give food advice to the personal genetic constitution. Consumer will be choosing food on the basis of their own genetic constitution within ten to twenty-five years. People will have a genetic passport that allows them to use personalized nutrition, personal food with a preventive function.[1592]

Nutrigenomics is not seen as a product category in itself, but rather as supporting technology for the development of foods of greater nutritional value, and of functional foods. [1593]

Jean Baptiste Lamarck developed at the end of the 18th century a theory which modern biologists rated as nonsense.

Lamarck explained nature as being controlled by three biological laws:

Environmental influence on organ development.
Change in Body structure based on use and disuse of parts.
Inheritance of acquired characteristics

Lamarck lived from 1744 to 1829. He was a French botanist and invertebrate zoologist. He wrote that acquired characteristics could be inherited to following generations, even not being genetically encoded. Genetic science experienced then a recession. It was only in 1865 that George Mendel published the "Mendel' s Laws" of autosomal inheritance, followed by Charles Darwin with "The Origin of Species" in 1859. Francis Galton (his cousin) rediscovered Mendel' s laws and is considered to be the father of modern genetics.
James Watson and Francis Crick discovered the DNA in 1940' s. The Human Genome Project begun in 1990.

Uses of food genomics

Through informatics driven metabolomic analysis it is possible to identify and predict the impact of diet on the health of individuals with different genotypes.

Metabolome: The small molecule inventory (SMI) or metabolome is a pattern of molecules that reflects the cell's statues. It is the totality of metabolic processes including anabolism and catabolism. It results from the expression of the genome and proteome in response to the cellular environment. The metabolome gives a direct picture of the cells activity and its environment.

The cumulative effects of all expressed and modified proteins represent an information which is stored in the small molecular inventory (SMI) of the cell. These molecules include important cellular function compounds, such as nucleotides, vitamins, antioxidants and catecholamines. This area of researche is called metabolomics.
When taken in its entirety it is not always necessary to know the identity of individual components in a metabolic profile. Systemic changes in pattern are indicative of specific states or of changes in status. This can be measured by quantifying the redox active components. Detecting and identifying subtle changes can be problematic with the sensitivity required to identify such molecules. New analytical technology addresses both problems using the central position of redox biochemistry in the biological process[1594]

The general aim of metabolomics is to identify, measure and interpret the complex time-related concentration, activity and flux of endogenous metabolites in cells, tissues, and other biosamples such as blood, urine, and saliva. Metabolites such as small molecules that are the products and intermediates of metabolism, carbohydrates, peptides, and lipids vary in concentration, size, structure, polarity, and functional groups. An integrated set of technologies is needed to address the entire spectrum of metabolomics.[1595]

Metabolomics in human blood: Mass spectrometry can now monitor enzymatic and hormonal regulation of thousands of metabolites by means of metabolomic techniques. The German Institute of Human Nutrition (DIFE) in cooperation with the Max-Planck Institute for molecular Genetics of Plants in Golm/potsdam and Metanomics in Berlin are adapting a plant analytic system for human tissue and plasma. A specific metabolite pattern in diabetes patients was possible to be identified. More detailed knowledge should allow the early identification of unfavorable metabolic profiles in order to develop preventive strategies.[1597]

Plagemann revives the theory of Jean Baptiste Lamarck quoting that a high diabetes risk can be passed on to several generations. This is not caused by a genetic modification, but is due to an acquired condition. Experiments with rats have demonstrated that diabetes leads to an increased level of insulin in the unborn. The cells of the brain where the experience of hunger or satiety are located are irreversibly damaged and the production of insulin excessively secreted. Diabetes and overwight is therefore programed[1598].

Martin Pedersen, group leader of a nutrigenomics team of researchers from Denmark and Japan of Chr Hansen, said that a project analyses the genetic code of bacteria to improve probiotic food products within the four-year duration of the project. [1593]

Supplementation during pregnancy

The mother's nutrition can be so important that it can alter her offspring's susceptibility to disease by changing gene expression, say researchers who claim to have explained for the first time how maternal nutrition can predetermine risk of obesity or cancer.

Scientists from Duke University in the US showed they could change the coat color of baby mice simply by feeding their mothers four common nutritional supplements before and during pregnancy

Dr Randy Jirtle, senior investigator of the study, published in today's issue of Molecular and Cellular Biology. "For the first time ever, we have shown precisely how nutritional supplementation to the mother can permanently alter gene expression in her offspring without altering the genes themselves." In experiments, pregnant mice that received vitamin B12, folic acid, choline and betaine (from sugar beets) gave birth to babies predominantly with brown coats. In contrast, pregnant mice that did not receive the nutritional supplements gave birth predominantly to mice with yellow coats. The non-supplemented mothers were not deficient in these nutrients.

A study of the cellular differences between the groups of baby mice showed that the extra nutrients reduced the expression of a specific gene, called Agouti, to cause the coat color change. Yet the Agouti gene itself remained unchanged. This is called 'DNA methylation', and it could potentially affect dozens of other genes that make humans and animals susceptible to cancer, obesity, diabetes, and even autism.

During DNA methylation a methyl group attaches to a gene at a specific point and alters its function. The methyl group silences the gene or reduces its expression inside a given cell, but does not actually change it. Such an effect is referred to as 'epigenetic' b

These changes occur early in embryonic development, before the mother would even be aware of the pregnancy. According to Dr. Jirtle, any environmental condition that impacts these windows in early development can result in developmental changes that are life-long, some of them beneficial and others detrimental. If such epigenetic alterations occur in the developing sperm or eggs,

Humans and other animals are susceptible to epigenetic changes because of an evolutionary trait in which "junk" remnants of viral infections, called "transposons," inserted themselves randomly within the human and animal genomes. If the transposons have inserted themselves in or near a functional gene, the gene can be inadvertently methylated, too, thereby reducing its expression.

More than 40 per cent of the human genome is comprised of transposons that are likely to be methylated, so any genes positioned near them could be at risk for inadvertent methylation. For example, methylation that occurs near or within a tumour suppressor gene can silence its anti-cancer activity, said Jirtle. Also they do not know which of the four nutrients caused methylation of the Agouti gene, revealing the uncertainty of nutrition's epigenetic effects on cells.

Methylating a single gene can also have multiple effects. For example, as well as changing coat color, mice that over-express the Agouti protein tend to be obese and susceptible to diabetes because the protein also binds with a receptor in the hypothalamus and interferes with the signal to stop eating. Methylating the Agouti gene in mice, therefore, also reduces their susceptibility to obesity, diabetes and cancer. The researchers stressed the importance of understanding the molecular effects of nutrition on cells, not just the outward manifestations of it.

Dr.Waterland says that diet, nutritional supplements and other seemingly innocuous compounds can alter the development in utero to such an extent that it changes the offspring's characteristics for life, and potentially that of future generations. Nutritional epigenetics could, for example, explain the differences between genetically identical twins, or the disparities in the incidence of stroke between the South and the North.

That is the reason why all supplements such as vitamines, minerals probiotics and a lot of other compounds should be analyzed carefully and nutrition should be kept as natural as possible.