By Yunzhi (Grace) Qian, PhD student at UNC Chapel Hill
When you visit your registered dietitian, they might give you generalized dietary recommendations like “you should consume more vegetables” or “please decrease sugar-sweetened beverage intake”. You might find these general recommendations less helpful since they are not targeting your specific needs. For individuals who are genetically predisposed to certain diseases, complying with general health suggestions might not be a good choice. With a one-size-fits-all approach that most dietitians are using, customers will get the same suggestions on nutrition consumption no matter how they differ in genetics, gut microbiome, gender, race, etc. One concern of the one-size-fits-all approach is that it neglects the individualized needs and differences.
Precision nutrition can evaluate one’s genetics, gut microbiome, and metabolic response to specific nutrient or dietary patterns and identify the best dietary plan for disease prevention and treatment. With the advance of modern technologies (e.g., metabolomics, epigenomics), it becomes increasingly important to understand the health effects of the complicated interaction among factors such as genetics and microbiome. The National Institutes of Health (NIH) provide funds for research in precision nutrition under the category of precision medicine in the 2020-2030 Strategic Plan, which aims to find the most efficient ways to prevent disease with a more personalized approach.
Precision nutrition and microbiome
The gut microbiota is a highly complex microbial community with functions such as bioactive compound production, immune regulation, energy homeostasis, and brain function. The gut microbiome varies significantly from host to host and is a potential candidate for precision nutrition. Since gut microbiota interacts with the host cells, we can see them as a biomarker to predict the effect of specific dietary patterns on host health, and to identify the optimal diet that fits individuals’ needs. For example, researchers at University of Illinois at Urbana-Champaign studied the impact of specific foods (e.g., avocados, broccoli, walnuts) on the human gut microbiota, and found that fecal bacteria can be used as biomarkers to predict food consumption.
Precision nutrition and genomics
Precision nutrition is interested in the physiological consequences of genetic variants and their interactions with nutrient intake and other lifestyle factors (e.g., physical exercise, dietary intake). Precision nutrition takes an individual’s genetics and epigenetics information into account. Genetics studies the genes that control our body, while epigenetics is the study of inheritable changes of the organisms caused by the modification of gene expression. Nutrigenomics studies the interaction between nutrition and genes, with focus on finding prevention and treatment of disease.
Some potential questions for precision nutrition in the area of disease management:
- How does one’s genetic profile is related to the consumption and metabolism of specific nutrient/diet?
- How can specific types of gut bacteria help improve blood glucose management? Futhermore, how do changes in diet affect the composition of gut microbiota and support the growth of a beneficial microbiota?
- How does an individual’s metabolic signature (small molecules produced when the body breaks down food, chemicals, and drugs) represent their dietary patterns, and is there an association between the metabolites and the risk of a particular disease?
Testing plays a crucial role in developing targeted nutrition interventions. However, current tests are not sufficient to cover individual variability. With nutrigenomics and microbiome analysis, researchers can investigate the role of genetic and gut microbiota in biological responses to diet. The understanding of how individual genetics and gut microbial communities influence variability related to nutritional exposures and obesity will be advanced.
Precision nutrition is still an emerging field. Consistent results in clinical trials are still needed before we can recommend specific dietary patterns to individuals. Some companies already offer individualized diets based on genetics or microbiome testing; however, more research is needed to test for the safety and efficacy of these diets.
Peer-edited by: Victoria C Daniels, M.S.
Image source: iStock
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