Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Learning to love bacteria: Stanford scientist highlights bugs’ benefits

24.02.2006


Bacteria are bad. Mothers and doctors, not to mention the cleaning product industry, repeatedly warn of their dangers. But a Stanford University School of Medicine microbiologist is raising the intriguing idea that persistent bacterial and viral infections have benefits.



Stanley Falkow, PhD, the Robert W. and Vivian K. Cahill Professor in Cancer Research, is publishing his thoughts on this topic in an essay in the Feb. 24 issue of the journal Cell, in which he asks, "Is persistent bacterial infection good for your health?" The essay is based on a talk he was invited to give at Cambridge University in November.

Falkow points out that the medical community and those who fund medical research focus on curing disease. He wonders if this single-mindedness might distract researchers from appreciating the beneficial contributions of micro-organisms to the body.


"Organisms that cause disease are usually considered in the context of harm and epidemics and so on," said Falkow. "But the fact is that a great number of organisms that infect humans come in and set up housekeeping as it were. There are no clinical symptoms of anything wrong and people take the organisms with them to their graves."

It’s not that the organisms in question - such as the bacteria that cause pneumonia or meningitis - are innocuous, he said. It’s just that most of the individuals do not get disease from being infected.

The best recent example of this, said Falkow, is H. pylori. First identified only 25 years ago, the organism earned researchers last year’s Nobel Prize in Medicine or Physiology for being implicated as a cause of ulcers and stomach cancer.

As is typical in the world of microbiology, though, it’s not a simple equation: being infected = ulcers or cancer. At least 80 percent of the world’s population is infected with H. pylori yet has no overt symptoms.

What makes the study of H. pylori even more perplexing is that as such advances as clean water and pasteurization are adopted, the prevalence of H. pylori infection has declined. On the one hand, this has been accompanied by a drop in the incidence of gastric cancer and ulcers. On the other, there has been an increase in esophageal cancer. H. pylori appear to protect against cancer of the esophagus. "So that says that there might be something about persistent infection that might be protective," said Falkow.

This raises the conundrum: By messing with the microbes, are we just replacing one disease with another?

Falkow’s lab has been studying the phenomenon of persistent infection for decades, in particular with H. pylori and Salmonella. He and his colleagues have shown that when infected with these organisms, mice initially show an inflammatory response that then settles down and stays with them for the rest of their lives.

Although very few of these organisms remain in the mice, it is enough to cause the immune system to have an ongoing response. "It’s not so much that the immune system has failed," Falkow explained, "but that the organisms have manipulated the immune system in such a way that they can’t be cleared." If the infections are cleared by antibiotic intervention, the mice are highly susceptible to re-infection, and the re-infection is more likely to progress to disease than the initial infection.

Furthermore, as many infectious diseases have decreased, autoimmune diseases such as ulcerative colitis, Crohn’s disease and diabetes have increased.

"All these observations have been made without necessarily trying to pull it all together," said Falkow. "So what I tried to do in this article is to point out that the continued presence of these organisms in human society may actually be beneficial to the host and that is why they are tolerated by the immune system."

It’s an intriguing idea that requires more research in animal models. "We don’t know what to look for per se," he said. "But we can guess that since a persistently infected host is constantly having its immune system stimulated and refined, that may provide it with resistance to other things."

He wondered whether, as seen with H. pylori, humans are also unknowingly causing the disappearance of other things that have been with us for all of our evolution, and that might play some role in our health. "Could it be this that is responsible for some of the things we see such as the failure of the immune system to act appropriately?" he asked.

The only answer to date is: "It’s complicated." Instead of a persistent infection, some people get very ill from organisms such as Salmonella, H. pylori, tuberculosis and meningitis. How the immune system responds differently in individuals demands further research.

Falkow credits his colleagues for providing the fodder for his essay.

Mitzi Baker | EurekAlert!
Further information:
http://www.stanford.edu

More articles from Health and Medicine:

nachricht The cytoskeleton of neurons has been found to be involved in Alzheimer's disease
18.01.2019 | University of the Basque Country

nachricht Bioinspired nanoscale drug delivery method developed by WSU, PNNL researchers
10.01.2019 | Washington State University

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Ten-year anniversary of the Neumayer Station III

The scientific and political community alike stress the importance of German Antarctic research

Joint Press Release from the BMBF and AWI

The Antarctic is a frigid continent south of the Antarctic Circle, where researchers are the only inhabitants. Despite the hostile conditions, here the Alfred...

Im Focus: Ultra ultrasound to transform new tech

World first experiments on sensor that may revolutionise everything from medical devices to unmanned vehicles

The new sensor - capable of detecting vibrations of living cells - may revolutionise everything from medical devices to unmanned vehicles.

Im Focus: Flying Optical Cats for Quantum Communication

Dead and alive at the same time? Researchers at the Max Planck Institute of Quantum Optics have implemented Erwin Schrödinger’s paradoxical gedanken experiment employing an entangled atom-light state.

In 1935 Erwin Schrödinger formulated a thought experiment designed to capture the paradoxical nature of quantum physics. The crucial element of this gedanken...

Im Focus: Nanocellulose for novel implants: Ears from the 3D-printer

Cellulose obtained from wood has amazing material properties. Empa researchers are now equipping the biodegradable material with additional functionalities to produce implants for cartilage diseases using 3D printing.

It all starts with an ear. Empa researcher Michael Hausmann removes the object shaped like a human ear from the 3D printer and explains:

Im Focus: Elucidating the Atomic Mechanism of Superlubricity

The phenomenon of so-called superlubricity is known, but so far the explanation at the atomic level has been missing: for example, how does extremely low friction occur in bearings? Researchers from the Fraunhofer Institutes IWM and IWS jointly deciphered a universal mechanism of superlubricity for certain diamond-like carbon layers in combination with organic lubricants. Based on this knowledge, it is now possible to formulate design rules for supra lubricating layer-lubricant combinations. The results are presented in an article in Nature Communications, volume 10.

One of the most important prerequisites for sustainable and environmentally friendly mobility is minimizing friction. Research and industry have been dedicated...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Our digital society in 2040

16.01.2019 | Event News

11th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Aachen, 3-4 April 2019

14.01.2019 | Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

 
Latest News

Additive manufacturing reflects fundamental metallurgical principles to create materials

18.01.2019 | Materials Sciences

How molecules teeter in a laser field

18.01.2019 | Life Sciences

The cytoskeleton of neurons has been found to be involved in Alzheimer's disease

18.01.2019 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>