Nutrigenomics: The Scientific Link Between Genetics and Nutrition

"Nutrigenomics: The Scientific Link Between Genetics and Nutrition".   A home study course I completed, put out by the Institute for Natural Resources and I am unable to locate an online version.   But I did find this link that outlines much of the same information:  Nutrigenomics

The article begings with a great introduction essentially introducing you to the world of nutrigenomics...did you ever wonder what it would be like if we knew what we could and couldn't eat from the day we are born?....or if we knew what we were predisposed to and could alter our eating habits specifically for those diseases. (Diabetes, heart disease, Cronhs, Cancer).   We may be able to with combining the worlds of Nutrition and Genomics.  "Nutrigenomics tries to determine the influence of common dietary ingredients on the genome and relate the resulting phenotypes to differences in the cellular and/or genetic response of biologic systems.  It analyzes the response of whole systems to nutrients and studies how food or food ingredients affect the metabolic pathways and alter gene expression".  

A major project took place from 1990-2003: The Human Genome Project yielded this field of nutrigenomics.  "Information from the human genome is making it possible to identify the genetic factors that influence a person's susceptibility to disease associated with diet.....In dietary related disorders, these interventions will involve dietary changes or the inclusions of functional food components, or both."

"Genes evolve in response to many types of environmental stimuli including nutrition." (genetics loads the gun, environment pulls the trigger).   There are genetic markers for many chronic diseases, one has not been found yet for FPIES but it is clear from the research thus far that there is a genetic component.   But what component turns it on?   It is the maternal diet?   Is it the infants diet?   Is it the gut flora?  It is antibiotic use? 

The tools used in Nutrigenomics are multidisplinary: Transcriptomics, Proteomics, Metabolomics, and Bioinformatics.  
"Transcriptomics measures the level of expression of all or a selected subset of genes based on the amount of RNA in a sample, using mircoarray analysis to see how genes react to change.  Nutrients can have a direct effect and interact with transription factors to regulate gene expression."  
"Proteomics is the study of proteins that can be expressed within an organism.  Proteomics focuses on the analysis of proteins and their interactions with other biologic molecules>'
"Metabolomics is the study of the complete set of metabolites that an organism produces.  Genes are turned on and off according to metabolic signals that the nucleus receives from internal factors such as horomones and external factors such as nutrients."
"Bioinformatics handle the vast amount of data produced.  It is now possible to predict gene function and identify the regulatory regions in the genome that influence gene expression". 

Understanding nutrigenomics requires an understanding of the cell.   DNA is the genetic material of the cell, it is arranged in untis called chromosomes, of which we have 23 and genes are spread throughout these chromosomes. 

The study of nutrigenomics also requires knowledge of polymorphisms.   "A polymorphism is the quality of existing in several different forms.  These differences can result from genetic predisposition, environmental influences, or a combination of both.....Several genetic polymorphisms important to nutrition have been identified."  These can be catagorized into 2 catagories:
1). Monogenic Diseases, in which a disease arises from on abnormal gene, these can range from lactose intolerance to PKU or galactosemia.  
2). Chronic Diseases such as cardiovascular disease, diabetes, cancer, obesity, and inflammatory bowel disease. 

The course goes on to discuss effects of micro and macro nutrients at the molecular level as well as the current dietary inteventions and guidelines for disease.   This is my job description in a nutshell so I skimmed over this! But essentially, nutrients have many roles in the body from influencing metabolism and physiology at the molecular level to fuel and co-factor roles.  The role of foods from macronutrients (carbohydrates, fats, proteins) to micronutrients (vitamins, minerals) play is complex and closely intertwined.   "Eat a balanced diet" is always good advice!  It does go on to discuss Dietary Interventions and Guidelines and how with the possibilities of nutrigenomics, one could "tailor" their diet to offer precise dietary advice for specific genetic testing results.   Currently, genetic predisposition with generalized healthy recommendations are what we work with but this can be restricting if there are multiple genes interacting with each other coupled with environmental variables that contribute to the diseases.   

It continues to describe how bioactive food components "alter gene expression in a host of cellular events".

The paragraph within the functional food chapter was of interest to me, and I think will be to other FPIES families: "One of the targets of functional foods will be the gut, which acts as an interface between ingested food and the body.  In addition, the gut serves as the barrier to harmful substances entering the circulation.   Ingestion of functional foods will be beneficial to the microflora of the gut.   These bacteria, in addition to their protective function, generate energy by digesting fermentable carbohydrates.  The microflora of the large intestine is aquired shortly after birth, and its composition is dependent on diet.   We all have our own specific microflora.  Certain species of gut microflora can help reduce the risk of gastrointestinal infections, constipation, irritable bowel syndrome, inflammatory bowel diseases, and possibly colorectal cancer.   Therefore, intestinal microflora could be a part of a personalized nutritional program." 

It goes on to describe probiotics and prebiotics.  "Probiotics and prebiotics could be developed to alter the microflora of the gut....a prebiotic is a non-digestible food ingredient that beneficially affects the host by selectively stimulating the growth and/or modifying the metabolic activity of one or a limited number of bacterial species in the colon that have the potential to improve host health....to be classified as a prebiotic, a food must not be absorbed in the upper part of the gastrointestinal tract and must stimulate growth of the beneficial microflora that is resident in the colon.   Prebiotics also have additional benefits on the immnue system and may inhibit the formation of adenomas and carcinomas".

The conclusion is "Genes are turned on and off by what we eat".   "The interaction between nutrition and the human genome determines gene expression and the metabolic response".  

So, we really are what we eat....