Researchers at King's College London and Imperial College London have discovered that people with fewer copies of a gene coding for a carb-digesting enzyme may be at higher risk of obesity.
The findings, published in Nature Genetics, suggest that dietary advice may need to be more tailored to an individual's digestive system, based on whether they have the genetic predisposition and necessary enzymes to digest different foods.
Salivary amylase plays a significant role in breaking down carbohydrates in the mouth at the start of the digestion process. The new study suggests that people with fewer copies of the AMY1 gene have lower levels of this enzyme and therefore will have more difficulty breaking down carbohydrates than those with more copies.
Previous research has found a genetic link between obesity and food behaviours and appetite, but the new discovery highlights a novel genetic link between metabolism and obesity. It suggests that people's bodies may react differently to the same type and amount of food, leading to weight gain in some and not in others. The effect of the genetic difference found in the latest study appears much stronger link than any of those found before.
Researchers first measured gene expression patterns in 149 Swedish families with differences in the levels of obesity and found unusual patterns around two amylase genes (AMY1 and AMY2), which code for salivary and pancreatic amylase. This was suggestive of a variation in copy numbers relating directly to obesity.
The finding was replicated strongly in 972 twins from TwinsUK, the biggest UK adult twin registry, which found a similar pattern of expression. The researchers then estimated the precise copy numbers of the amylase gene in the DNA of a further 481 Swedish subjects, 1,479 subjects from TwinsUK and 2,137 subjects from the DESIR project.
The collaborative team found that the number of copies of the AMY1 gene (salivary amylase) was consistently linked to obesity. Further replication in French and Chinese patients with and without obesity showed the same patterns.
A lower estimated AMY1 copy-number showed a significantly increased risk of obesity in all samples and this translated to an approximate eight-fold difference in the risk of obesity between those subjects with the highest number of copies of the gene and those with the lowest.
Standard Genome wide mapping methods (GWAS) had missed this strong association as the area is technically hard to map. This variation in copy numbers, also known as 'copy number variants' (CNV) has been underestimated as a genetic cause of disease, but the link between CNV in the amylase gene and obesity provides an indication that other major diseases may be influenced by similar mechanisms.
Professor Tim Spector, Head of the Department of Twin Research and Genetic Epidemiology at King's College London and joint lead investigator said: "These findings are very exciting. While studies to date have mainly found small effect genes that alter eating behaviour, we discovered how the digestive 'tools' in your metabolism vary between people – and the genes coding for these – can have a large influence on your weight.
"The next step is to find out more about the activity of this digestive enzyme, and whether this might prove a useful biomarker or target for the treatment of obesity.
"In the future, a simple blood or saliva test might be used to measure levels of key enzymes such as amylase in the body and therefore shape dietary advice for both overweight and underweight people. Treatments are a long way away but this is an important step in realising that all of us digest and metabolise food differently – and we can move away from 'one-size fits all diets' to more personalised approaches."
Hannah Pluthero | EurekAlert!
Symbiotic bacteria: from hitchhiker to beetle bodyguard
28.04.2017 | Johannes Gutenberg-Universität Mainz
Nose2Brain – Better Therapy for Multiple Sclerosis
28.04.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
28.04.2017 | Event News
20.04.2017 | Event News
18.04.2017 | Event News
28.04.2017 | Medical Engineering
28.04.2017 | Earth Sciences
28.04.2017 | Life Sciences