A new study shows that the relationship between our genetic make-up and our metabolism – the chemistry of life that goes on inside our cells – is a two-way street. Not only do our genes regulate how the food we eat is broken down, but how our food is broken down regulates our genes.
Providing new evidence to support the old adage “we are what we eat,” the study is published in the journal Nature Microbiology.
The authors – an international team led by Dr. Markus Ralser of the University of Cambridge and the Francis Crick Institute in London, both in the UK – conclude that nearly all of our genes may be influenced by the food we eat.
Cell behavior is regulated by two things: the genes in the cell’s nucleus that hold the blueprint of the organism and its components, and metabolism – the set of chemical reactions needed to maintain the cell and sustain life.
Since Gregor Mendel – the “father of genetics” – and his work on pea plants hinted at the existence of genes over 150 years ago, we have learned that the genome, or complete DNA blueprint of an organism, determines to a large extent how that organism looks.
We have also discovered that an individual is not just a product of genetics, there is also epigenetics, which can modify the genome. Epigenetics means that the blueprint held in DNA can vary in that genes can be switched on and off by other genes or bits of DNA, and even by proteins that attach “epigenetic markers” onto the DNA.
More recently, researchers have been talking about another player in our gene regulation: the metabolic network of biochemical reactions that occur within cells.
These metabolic reactions can vary, depending on the availability of nutrients, such as sugars, amino acids, fatty acids and vitamins, that come from the food that we eat.
To examine this further, the team decided to investigate metabolism in yeast cells. In terms of cell biochemistry, yeast has remarkably similar qualities to humans and is much easier to manipulate in the lab.
To see how metabolism might influence genes and the molecules they produce, the researchers varied the levels of metabolites – the end-products of metabolic reactions – in the yeast cells.
They found that changing cell metabolism affected nearly 90% of yeast genes and the molecules they produce.
Dr. Rasler says cell metabolism appears to play a more dynamic role in cells than previously thought; it seems nearly all of a cell’s genes are affected by changes to the nutrients available. He adds:
“In fact, in many cases the effects were so strong, that changing a cell’s metabolic profile could make some of its genes behave in a completely different manner.”
The team believes there could be wide-ranging implications to their findings. For instance, they could explain how different people respond differently to the same drug.
The findings could also improve our understanding of cancer and why some drugs fail in certain patients. For example, tumor cells develop several genetic mutations – these influence cell metabolism, which in turn affects the behavior of genes.
There is also another practical implication from the findings that should interest scientists. When scientists publish the results of experiments, says Dr. Rasler, other teams often find they do not get the same results when they try to repeat the experiments.
He says that “we often blame sloppy researchers for that,” but these new findings suggest it could be that small metabolic differences change the results of the experiments. Dr. Rasler concludes:
“We need to establish new laboratory procedures that control better for differences in metabolism. This will help us to design better and more reliable experiments.”
In 2014, Medical News Today learned how another group of researchers in Cambridge, UK, developed a powerful new technique that uses a single cell to map the epigenetic marks that life leaves on our DNA.