Metabolic fingerprints offer fresh clues and a new path toward personalized medi

[Guest guest]

Metabolic fingerprints offer fresh clues and a new path toward personalized

medicine

http://www.eurekalert.org/pub_releases/2010-04/tum-mfo040910.php

Munich-area study pioneers phenotyping of the human 'metabolome'

The old excuse, " I am only overweight because of my genes, " is suddenly gaining

credibility as researchers uncover ever more evidence that the way our bodies

digest and process nutrients in the food we eat is different for every person.

The budding discipline of metabolomics strives to investigate these differences

in a scientific manner. Nutrition scientists and food chemists at the Technische

Universitaet Muenchen are on the front line: They have joined forces with

outside experts to form the Munich Functional Metabolomics Initiative, an

interdisciplinary network for driving research in this field.

(A video report, in both English and German versions, is available at:

http://www.youtube.com/user/TUMuenchen1 and www.tum.de/film.)

When it comes to our genes, we are 99.9 percent identical. And yet, every person

looks different. But it does not end there. Recent studies confirm that

individual differences apply not only to superficial traits – they also define

our metabolism. Researchers are now asking how this is even possible considering

the pool of nearly identical genomes. Only once the fundamental mechanisms are

uncovered can conditions such as diabetes or cardiovascular disease that stem

from metabolic disorders be fully understood and more effectively treated.

Experts at the Center for Life and Food Sciences Weihenstephan of the Technische

Universitaet Muenchen (TUM) have given high priority to the search for answers.

To this end the researchers have initiated a study called HuMet. Fifteen healthy

young men were closely scrutinized for four days. They had to fast, eat and

drink various types of standardized nutrition, and submit to a variety of

physical tests. All the while numerous blood, urine, and breath samples were

taken. Hannelore , professor of nutritional physiology, and Prof. Hans

Hauner, a nutritional physician at the TUM, carried out the nutritional protocol

and test procedures, while Prof. Hofmann from the Chair of Food Chemistry

and Molecular Sensory Science used the samples for a multitude of tests using

his team's high-performance analytic tools.

" In general, all people react similarly to specific nutritional components, "

says Hannelore , " but there are big differences in their responses. " For

example, when a test subject is given a certain amount of glucose, his or her

blood sugar level rises and then falls again. But even early results of the

HuMet study revealed some astonishing details: In the beginning, on an empty

stomach, the values were extremely uniform; however, every test subject

responded differently after ingesting glucose. " Obviously all values will rise, "

says. " The blood sugar level must go up. But it is very interesting to

observe the differences in the way the levels rise and fall off again. Only

after four hours were the blood sugar levels of the test subjects level again. "

describes our metabolism as a mechanism that can be pushed and pulled

like the bellows of an accordion. One thing the researchers want to determine is

just how wide the range is, and modern methods of high-performance analytics

make that possible. " The HuMet study actually gave the impetus for the entire

field of research, " TUM food chemist Hofmann is pleased to note. " All

researchers in greater Munich interested in advancing the field of metabolomics,

for example our colleagues from the Helmholz Zentrum Muenchen, are collaborating

with us in the Munich Functional Metabolomics Initiative. " All participating

researchers received a portion of all plasma and urine samples to evaluate using

their own special measuring methods. Prof. Hofmann's team relied primarily on

the methods of liquid chromatography-tandem mass spectroscopy and NMR

spectroscopy.

" We need to develop the methods further to do justice to the complexity of the

body's metabolism. Today, we are at a level comparable to that of digital

cameras in the 1980s, " says Hofmann. " We must increase the resolution of our

analytical camera to obtain a sharp image of all metabolic by-products. " And if

we want to describe metabolic dynamics next, we will need to make a short movie.

" For this we want to automate our procedure so that it will deliver a large

number of high-resolution images over a short period of time. These can then be

combined into a sequence, analogous to a flip-book. "

Once this becomes possible, the researchers will be able to look deep into

metabolic processes. Their biggest hope: that metabolomics will one day enable

custom-tailored therapies for people with metabolic disorders and nutrition

plans for people wanting to lose weight