Navigation Links
A Little Dirt May Be a Good Thing
Date:9/9/2011

By Dennis Thompson
HealthDay Reporter

FRIDAY, Sept. 9 (HealthDay News) -- Good hygiene has saved millions of lives, protecting people from countless bacterial and viral infections, according to the U.S. Centers for Disease Control and Prevention.

But there is growing concern that strict adherence to good hygiene, though a valuable means of protecting health, has left humans open to other forms of illness.

Proponents of the "hygiene hypothesis" believe that reduced exposure to bacteria, viruses and parasites have impaired the immune system's ability to properly respond to environmental challenges.

Researchers have identified the hygiene hypothesis as a possible cause or exacerbating factor in a number of illnesses and medical problems, said Dr. Graham A.W. Rook, a professor in the department of infection at the Centre for Clinical Microbiology at the University College London. These include:

  • Severe allergic reactions.
  • Gastrointestinal disorders, such as inflammatory bowel disease and Crohn's disease.
  • Autoimmune disorders, such as type 1 diabetes and multiple sclerosis.

"The evidence for all this is very, very powerful," Rook said. "It's very easy to show if you live on a farm or keep a dog, you're less likely to have these disorders. If you are the youngest child in a big family, you're less likely to have these disorders."

The hygiene hypothesis has its roots in the theory of evolution, he said.

"The bottom line is organisms that were present in mud, untreated water and feces were with us right from the start of humanity," Rook explained. Proponents of the hygiene hypothesis believe that the human body adapted to these organisms and began using them as a means of training the immune system.

"What has happened over the course of evolution is, because these bugs had to be tolerated, they came to activate the tolerance of the immune system," Rook said. "They are the police force that keeps the immune system from becoming trigger-happy. Basically, the immune system is now attacking things it shouldn't be attacking."

Dr. Mitchell H. Grayson, an associate professor of pediatrics at the Medical College of Wisconsin in Milwaukee, said that the hygiene hypothesis is most strongly linked to an increase in allergic diseases and asthma.

"It's thought to have something to do with the way your immune system develops and is programmed," Grayson said. Bacteria in the environment teach an immune response to allergens that is more moderate and less severe. "In the absence of these bacteria, the immune system is thought to become more prone to allergic disease," he said.

Rook said that other researchers have used the hygiene hypothesis to show that parasitic infections can aid in the treatment of such conditions as multiple sclerosis and Crohn's disease.

Argentinean researchers, for instance, have shown that the presence of intestinal parasites can moderate the progression of multiple sclerosis. Follow-up studies indicated that, when people were treated for their parasitic infection, they had a relapse of MS.

A research team at the University of Iowa found similar results related to Crohn's disease, showing that intestinal parasites helped regulate the autoimmune reaction that causes the intestinal disorder.

On the flip side, such revelations carry risks. Doctors are concerned that some might use the hygiene hypothesis as an excuse to abandon good hygiene, causing a surge in diseases such as dysentery and cholera.

"Public health and sanitation has been the single greatest improvement in our life expectancy," Grayson said. "I would not recommend living less cleanly."

On the other hand, tolerance of a little dirt here and there won't hurt.

"If your kids come back from the garden with a little mud on their hands, it's not a bad thing," Rook said. "They don't necessarily have to wash their hands before picking up a sandwich."

In general, though, it's wise to maintain good overall hygiene, he said, and wait for the scientists to figure all this out. Larger studies are underway to determine the exact mechanism by which bacteria and parasites are causing the immune system to moderate its response, Rook said.

"We need to figure out how to replace what is good from the microbiological environment while maintaining the advances of good hygiene so we can get the best of both worlds," Rook said.

More information

The U.S. National Institute of Allergy and Infectious Diseases has more on the role of microbes and bacteria in sickness and health.

SOURCES: Graham A.W. Rook, M.D., professor, department of infection, Centre for Clinical Microbiology, University College London, London, U.K.; Mitchell H. Grayson, M.D., associate professor, pediatrics, Medical College of Wisconsin, Milwaukee, Wis.


'/>"/>
Copyright©2010 ScoutNews,LLC.
All rights reserved  

Related medicine news :

1. As Venus Williams Bows Out of U.S. Open, Little-Known Disease Takes Center Court
2. A Little Exercise Goes a Long Way to Cut Disease, Death Risk
3. Even a Little Exercise Helps the Heart, Study Finds
4. Theres a Little Neanderthal in Most of Us
5. High School Kids Get Too Many Sugary Drinks, Too Little Exercise: CDC
6. Too Little Sleep in Preschool Years May Predict ADHD
7. Poll Finds Little Support for GOP Plan to Privatize Medicare
8. Bathroom Injuries a Little-Known Problem
9. Chiropractic manipulation results in little or no risk of chest injury
10. Little Evidence That Diet, Lifestyle Cuts Alzheimers Risk
11. Even a Little Exercise May Protect Against Colon Polyps
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
A Little Dirt May Be a Good Thing
(Date:12/2/2016)... ... December 02, 2016 , ... Universal Medical Systems, ... and the first company to offer robotic imaging to veterinary medicine is sponsoring ... # 941 for the American Association of Equine Practitioners 62nd Annual Convention from ...
(Date:12/2/2016)... ... , ... Rijuven Corp launches rejiva ( http://www.rejiva.com ), a unique wearable technology ... health technology on the market can deliver all that rejiva can. , “Rejiva promotes ... their health than the usual heart rate and steps taken”, adds Evens Augustin, CEO ...
(Date:12/2/2016)... Viejo, California (PRWEB) , ... December 02, 2016 , ... ... will allow FCPX editors to create versatile lower third titles with just a few ... , Pro3rd Accents Volume 2 includes 30 lower third animations. Choose from various styles ...
(Date:12/2/2016)... ... 02, 2016 , ... On November 24th, 2016, Thanksgiving morning, ... different sites throughout Miami-Dade and Broward counties. This is the largest meal delivery ... Thanksgiving morning by putting together individual meals via assembly lines and passing them ...
(Date:12/2/2016)... ... December 02, 2016 , ... Date aired: November ... Type 2 Diabetes: The Owner’s Manual, http://realtimepressrelease.com/press-releases-tagged-with/daryl-wein , Sharon Kleyne, ... Water, Global Climate Change and Your Health radio program syndicated on Voice of ...
Breaking Medicine News(10 mins):
(Date:12/2/2016)... , December 2, 2016 ... Vitro Diagnostics/IVD Market by Product (Instruments, Reagents, Software), ... (Diabetes, Oncology, Cardiology, Nephrology, Infectious Diseases) - Forecast ... is valued at USD 60.22 Billion in 2016. ... CAGR of 5.5% during the forecast period (2016-2021) ...
(Date:12/2/2016)...  PipelineRx, a leading medication management technology company ... of its SaaS-based telepharmacy platform, PowerGridRx™ , ... Midyear Clinical Meeting and Exhibition, December 5-7 in ... 300 hospital clients nationally, the Company is a ... dramatically improve pharmacy operations, enhance patient safety, and ...
(Date:12/2/2016)... -- On Thursday, December 1st 2016, the ... development and innovation in the biopharmaceutical industry at its ... the presence of Sergey Tsyb, Vice Minister of Industry ... , Natalia Sanina, First Vice Chairman of the State ... Roszdravnadzor, National Service of Control in Healthcare, Sergey Muravev, ...
Breaking Medicine Technology: