Contact Information:

Media Contact

Dr. Markus Stoffel

Twitter: ETH_en

Kredyty mieszkaniowe Kredyty mieszkaniowe

Sprawdź aktualny ranking najlepszych kredytów mieszkaniowych w Polsce - atrakcyjne kredytowanie nieruchomości. - Press Release Distribution
RSS - Press News Release
Add Press Release

MicroRNAs are digested, not absorbed

( This news release is available in German.

The scientific world was astonished when, in 2011, Chinese researchers claimed to have found evidence suggesting that minute fragments of plant genetic material - so-called microRNA molecules - of rice ingested from food could play a role in regulating physiological processes in the human body. If this is indeed true, it might even be possible to deliberately modify human physiological functions via this route, for instance by incorporating microRNAs into novel functional foods. As a strategy, this holds considerable potential. For example, certain endogenous microRNA molecules have been shown to suppress cancer cell growth, and others are known to be involved in the development of diseases such as obesity and diabetes.

The idea of using microRNAs as a functional food ingredient was supported by American researchers who, in a study published last year, concluded that microRNAs ingested from cow's milk is absorbed and can pass into the human bloodstream. Mammalian milk generally contains large quantities of microRNAs. For many years, scientists have therefore been investigating the possibility that these molecules may naturally modify the metabolism, especially the immune system of infants.

Controversial studies

Nonetheless, the studies of microRNA transfer from rice and cow's milk stirred up much controversy within the scientific community. Some supporting data in both of these studies remained ambiguous. These reservations have now been reinforced by a new study led by Markus Stoffel, a professor in the Department of Biology at ETH Zurich. His experiments using mouse models show that the dietary uptake of microRNAs is barely significant, and certainly insufficient to affect physiological functions. Moreover, the microRNA molecules are broken down in the small intestine. This effectively dampens the enthusiasm for functional foods based on microRNAs.

The ETH biologists used two families of mice to conduct their study. One descended from a standard race of laboratory mice (the so-called wild type), while the other consisted of mice in which a specific microRNA molecule had been knocked out. The molecule in question goes by the name of miR-375 and is normally produced in the pancreas, the intestine and the mammary glands. It is one of the microRNA molecules found in high concentrations in maternal milk.

Experiment using foster mothers

The scientists allowed the two mouse families to reproduce, but exchanged their offspring immediately after birth. In this way, the researchers were able to conduct their experiments on juvenile mice that did not express miR-375 but were suckled by a female whose milk contained miR-375.

When the researchers examined the stomach milk content of the juvenile mice raised in this way, they found high concentrations of miR-375. "MicroRNA molecules are relatively resistant to gastric acids," explains Stoffel. On the other hand, they only found minute traces of miR-375 in other parts of the body. The concentrations they measured were at least a thousand times lower than the level needed to regulate gene expression and thereby modify physiological and metabolic processes. In particular, the researchers detected nothing more than the slightest concentrations of miR-375 in the cellular lining of the small intestine. This is relevant because all digested food has to pass through this barrier before entering the bloodstream. Furthermore, analysis of the blood and the liver provided no evidence of the presence of miR-375.

Breakdown of microRNAs

"We can only assume that the microRNAs are broken down into smaller components by the enzymes in the gastrointestinal tract," says Stoffel. In a laboratory experiment in which milk containing miRNAs is mixed with digestive juices present in the small intestine the researchers proved that this is indeed the case.

But if microRNAs in maternal milk are broken down before they enter the bloodstream of the suckling infant, why did Mother Nature go to such pains to ensure that maternal milk contains large quantities of microRNAs? For Stoffel, the answer may be simple: Babies grow rapidly and to do so they need RNA building blocks in addition to the many other nutrients that promote cell growth. These components are produced in the small intestine by the digestive processes that break down microRNAs from the mother's milk. "It is reasonable to conclude that these components are quite simply there to nourish the infant," says Stoffel.


Literature reference Title AC, Denzler R, Stoffel M: Uptake and function studies of maternal milk-derived microRNAs. Journal of Biological Chemistry, 3 August 2015, doi: 10.1074/jbc.M115.676734 []


Secukinumab in plaque psoriasis: Manufacturer dossier provided no hint of an added benefit

Secukinumab (trade name: Cosentyx) has been approved since January 2015 for adults with moderate to severe plaque psoriasis. The German Institute for Quality and Efficiency in Health Care (IQWiG) examined in a dossier assessment whether this drug offers an added benefit over the appropriate comparator therapy. Such an added benefit cannot be derived from the dossier, however: In patients who are candidates for systemic treatment, an indirect comparison provided no suitable data because the minimum study duration had not been reached. In adults in whom other systemic treatments ...

Indications of the origin of the Spin Seebeck effect discovered

This news release is available in German. The recovery of waste heat in all kinds of processes poses one of the main challenges of our time to making established processes more energy-efficient and thus more environmentally friendly. The Spin Seebeck effect (SSE) is a novel, only rudimentarily understood effect, which allows for the conversion of a heat flux into electrical energy, even in electrically non-conducting materials. A team of physicists at Johannes Gutenberg University Mainz (JGU), the University of Konstanz, TU Kaiserslautern, and the Massachusetts Institute ...

WSU researchers create super-stretchable metallic conductors for flexible electronics

PULLMAN, Wash.--Washington State University researchers have discovered how to stretch metal films used in flexible electronics to twice their size without breaking. The discovery could lead to dramatic improvements and addresses one of the biggest challenges in flexible electronics, an industry still in its infancy with applications such as bendable batteries, robotic skins, wearable monitoring devices and sensors, and connected fabrics. The work was led by Rahul Panat and Indranath Dutta, researchers in Voiland College's School of Mechanical and Materials Engineering, ...

Survey reinforces further understanding of dietary deficiencies and optimum nutrition needed

September 8, 2015, New York, New York- Data from a three-country survey seeking to understand beliefs of adults on the role of diet for optimal health, as well as consumption of key micronutrients including Omega-3 and Vitamin D, will be published in the November/December issue of Nutrition Today. The survey of 3,000 American, British and German adults found that 72 percent reported having a "healthy" or "optimal" diet and more than half (52 percent) believed they consume all the key nutrients needed for optimal nutrition through food sources alone. However, the prevalence ...

Reviving extinct Mediterranean forests, urban land-sparing, ocean noise pollution

Extinct Mediterranean forests of biblical times could return and thrive in warmer, drier future. The Mediterranean has cradled humanity and our cities, farms, domesticated animals, and logging habits for many thousands of years. During the last 5 to 8 millennia, as people developed farming and settled in cities, the landscape has gradually changed from a thick canopy of trees to open grass and shrubs. The ghosts of Sicily's extinct evergreen forests of holm oak (Quercus ilex) and olive trees (Olea europaea) remain in the record of pollen left in the lakebed sediments. ...

Brain damage during stroke may point to source of addiction

A pair of studies suggests that a region of the brain - called the insular cortex - may hold the key to treating addiction. Scientists have come to this conclusion after finding that smokers who suffered a stroke in the insular cortex were far more likely to quit smoking and experience fewer and less severe withdrawal symptoms than those with strokes in other parts of the brain. "These findings indicate that the insular cortex may play a central role in addiction," said Amir Abdolahi Ph.D., M.P.H., lead author of the studies. "When this part of the brain is damaged during ...

Biomarker helps predict survival time in gastric cancer patients

Philadelphia, PA, September 8, 2015 - Gastric cancer poses a significant health problem in developing countries and is typically associated with late-stage diagnosis and high mortality. A new study in The American Journal of Pathology points to a pivotal role played by the biomarker microRNA (miR)-506 in gastric cancer. Patients whose primary gastric cancer lesions express high levels of miR-506 have significantly longer survival times compared to patients with low miR-506 expression. In addition, miR-506 suppresses tumor growth, blood vessel formation, and metastasis. "Epithelial-to-mesenchymal ...

Policy recommendations for use of telemedicine in primary care

1. ACP recommends policies for practicing telemedicine in primary care Free: Editorial: URLs go live when embargo lifts In a new position paper, the American College of Physicians (ACP) says that telemedicine can improve access to care, but policies are needed to balance the benefits and risks for both patients and physicians. The authors note that conscious scrutiny is especially important as policymakers and stakeholders shape the landscape for ...

Ancient genomes link early farmers to Basques

Ancient genomes link early farmers to Basques
An international team led by researchers at Uppsala University reports a surprising discovery from the genomes of eight Iberian Stone-Age farmer remains. The analyses revealed that early Iberian farmers are the closest ancestors to modern-day Basques, in contrast previous hypotheses that linked Basques to earlier pre-farming groups. The team could also demonstrate that farming was brought to Iberia by the same/similar groups that migrated to northern and central Europe and that the incoming farmers admixed with local, Iberian hunter-gather groups, a process that continued ...

'Clever adaptation' allows yeast infection fungus to evade immune system attack

Johns Hopkins Bloomberg School of Public Health researchers say they have discovered a new way that the most prevalent disease-causing fungus can thwart immune system attacks. The findings, published Sept. 7 in the Proceedings of the National Academy of Sciences, offer new clues about how Candida albicans, the fungus responsible for vaginal yeast infections and the mouth infection thrush, is able to cause a deadly infection once it enters the bloodstream. When the body is faced with an infection, cells give a burst of free radicals to kill the germs. C. albicans ...


How your brain decides blame and punishment -- and how it can be changed

Uniquely human brain region enables punishment decisions

Pinpointing punishment

Chapman University publishes research on attractiveness and mating

E-cigarettes: Special issue from Nicotine & Tobacco Research

Placental problems in early pregnancy associated with 5-fold increased risk of OB & fetal disorders

UT study: Invasive brood parasites a threat to native bird species

Criminals acquire guns through social connections

Restoring ocean health

Report: Cancer remains leading cause of death in US Hispanics

Twin study suggests genetic factors contribute to insomnia in adults

To be fragrant or not: Why do some male hairstreak butterflies lack scent organs?

International team discovers natural defense against HIV

Bolivian biodiversity observatory takes its first steps

Choice of college major influences lifetime earnings more than simply getting a degree

Dominant strain of drug-resistant MRSA decreases in hospitals, but persists in community

Synthetic biology needs robust safety mechanisms before real world application

US defense agencies increase investment in federal synthetic biology research

Robots help to map England's only deep-water Marine Conservation Zone

Mayo researchers identify protein -- may predict who will respond to PD-1 immunotherapy for melanoma

How much water do US fracking operations really use?

New approach to mammograms could improve reliability

The influence of citizen science grows despite some resistance

Unlocking secrets of how fossils form

What happens on the molecular level when smog gets into the lungs?

Using ultrasound to clean medical instruments

Platinum and iron oxide working together get the job done

Tiny silica particles could be used to repair damaged teeth, research shows

A quantum lab for everyone

No way? Charity's logo may influence perception of food in package

[] MicroRNAs are digested, not absorbed is a service of DragonFly Company. All Rights Reserved.
Issuers of news releases are solely responsible for the accuracy of their content.