Tag: germs

Is Hand Sanitizer Killing You?

Parents have made an enemy of bacteria for years. They’ve sanitized tabletops, disinfected playthings and wiped down grocery store carts to keep their children safe from unseen germs.

That instinct is a natural one, experts say, but emerging research about the body’s bacteria, fungi and other cells that cover our skin, gastrointestinal tract and other areas suggests that we may be taking hygiene vigilance a little too far.

That, in the long run, weakens our immune systems.

Scientists are only beginning to understand the millions of microbes that make up the human microbiome, said UC Davis microbiologist Jonathan Eisen, but researchers are finding that antibiotics.

Household disinfectants and other sanitizing products are also killing the “good bacteria” that help our bodies fend off disease.




Many believe that the shortage of certain microbes explains recent spikes in childhood allergies and asthma.

People in developing countries, who grow up in less sterile environments, eat mostly non-processed foods and spend more time around people and animals, have more varieties of microbes in their gastrointestinal tracts than people in the United States, recent studies show.

At the same time, food allergy rates are lower in Africa and South America than in North America, Western Europe and Australia, according to the World Allergy Organization.

The findings play into the “hygiene hypothesis,” or the idea that childhood infections acquired through unhygienic contact bolster the immune system against disease later in life.

Of course, too many germs can also carry risks for children, said Dr. Ralph Morris, a Minnesota physician.

So what is the microbiome anyway?

The microbiome is made up of trillions of bacterial cells that we pick up from the world. They’re mostly concentrated in the gastrointestinal tract, but they also live in the lungs, mouth and other parts of the body.

Microbes assist in food digestion and trigger the immune system to fight illness. Some microbes appear to contribute to weight gain and others cause inflammation.

A difference in microbial makeup can predispose people to certain diseases or change the way they react to drug therapies.

 

How is it formed?

Germ exposure starts in utero and keeps forming through adulthood, making the first few months and years of a child’s life a crucial time for building a healthy microbiome.

Many experts, including Roseville allergist and immunologist Dr. Travis Miller, believe the ways babies are delivered help determine their future health.

Babies born vaginally take in healthy microbes from the birth canal, organisms that babies delivered by cesarean section don’t pick up, Miller said.

That may place C-section babies at a disadvantage from the get-go, he said.

How dirty is dangerous?

Land Park mother Amanda Bauer said she tries to be careful about keeping her two young daughters clean.

She doesn’t carry hand sanitizer around with her, she said, but always makes sure her 7- and 9-year-olds wash their hands after going to the grocery store.

Around the house, she cleans off door handles, remote controls and other heavily touched items with Lysol wipes, especially when someone is sick.

Recent science supports Bauer’s beliefs.

A study from Swedish researchers found that children whose families washed dishes by hand had significantly lower rates of eczema and slightly lower rates of allergies than children whose families used a dishwasher.

Other studies have shown children who live with dogs and cats tend to be healthier because the pets pass on their own beneficial microbes.

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Bacteria On Space Station Likely From Germy Humans, Not Aliens

Living bacteria have been found on the outside of the International Space Station, a Russian cosmonaut told the state news agency TASS this week.

Anton Shkaplerov, who will lead Russia’s ISS crew in December, said that previous cosmonauts swabbed the station’s Russian segment during spacewalks and sent the samples back to Earth.

The samples came from places on the station that had accumulated fuel waste, as well as other obscure nooks and crannies.

Their tests showed that the swabs held types of bacteria that were not on the module when it originally launched into orbit, Shkaplerov says.

In his interview with TASS, Shkaplerov says the bacteria “have come from outer space and settled along the external surface“, a claim that sparked some media outlets to issue frenzied reports about aliens colonizing the space station.

For now, though, details about the swabbing experiment are thin on the ground.




Shkaplerov did not note whether the study has been vetted by a peer-reviewed journal, which means it’s unclear exactly when and how the full experiment was conducted, or how the team avoided any contamination from much more mundane bacteria on the cosmonauts or in the Earth-bound lab.

Interview requests with the Russian space agency were unanswered when this article went to press. Up in the vacuum of space, microbes have to deal with turbulent temperatures, cosmic radiation, and ultraviolet light.

But Earth is home to plenty of hardy organisms that can survive in extreme environments, like virtually indestructible tardigrades.

Sometimes, researchers intentionally send terrestrial contaminants, such as E. coli and rocks covered in bacteria, into space to see how it will react.

And TASS reports that on a previous ISS mission, bacteria accidentally hitched a ride to the station on tablet PCs and other materials.

Scientists sent these objects up to see how they would fare in space, and the freeriding organisms managed to infiltrate the outside of the station.

They remained there for three years, braving temperatures fluctuating between -150 and 150 degrees Celsius.

 

These types of discoveries present concerns for scientists trying to limit the spread of human germs on other worlds.

NASA in particular has set strict limits on its interplanetary contamination.

Apollo astronauts were quarantined when they returned from their missions, for example, to prevent extraterrestrial germs from making their way out into the world.

And almost all equipment from Earth is sterilized before it heads skyward, either with extreme heat or an alcohol bath, depending on its intended destination.

These treatments are especially important for missions sent to Mars, which may have once hosted its own life-forms, leaving fossil traces in the rusty rocks.

But all bets may be off when and if we manage to send humans to explore Mars, writes The Planetary Society’s Emily Lakdawalla: “Once we’ve put humans on the surface, alive or dead, it becomes much, much harder to identify native Martian life.”

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Germs May Be Valuable Passengers on Mission To Mars

Astronauts on space missions to Mars may need more germs on the ship with them to stay in good health, a new study suggests.

As scientists prepare for a mission to Mars in the coming decades, the health and safety of astronauts is a top priority.

In this new research, scientists honed in on the microorganisms that would be living in close quarters with crews aboard spacecraft.

Researchers from Germany, the United Kingdom and Austria, led by the German Aerospace Center, enlisted a crew of six male “Marsonauts.” They lived inside a mock spacecraft in Moscow from June 2010 to November 2011.

During the mock Mars mission, the researchers monitored how the composition of bacteria changed over time.

What they found was that the diversity of germs dropped dramatically during the equivalent of a space flight to Mars.




Until now, little was known about the influence of long-term confinement on the microorganisms that live inside habitats that may one day be used to travel to other planets, and whether the structure of the microbiota changes with time,” said study author Petra Schwendner, from the University of Edinburgh.

Ours is the first comprehensive long-time study that investigates the microbial load, diversity and dynamics in a closed habitat – a mock-up spacecraft – for 520 days, the full duration of a simulated flight to Mars,” she said.

During the mock mission, the crew never left the closed habitat. They were also subjected to a regimented lifestyle that future Mars astronauts will face.

This involved a strict diet and schedule, which included cleaning the habitat and conducting scientific experiments.

The crew also collected 360 microbial samples from the air and various surfaces at 18 intervals.

The study showed communal areas, sleep areas, the gym, and the bathroom had the greatest volume and diversity of bacteria while the medical space had the least.

The researchers noted, however, that microbial diversity aboard the “spacecraft” declined dramatically during the mission.

The findings were published Oct. 3 in the journal Microbiome.

In addition to potential health risks for the crew, some of these microorganisms could have a negative impact on spacecraft, as they grow on and might damage spacecraft material,” Schwendner said in a journal news release.

To ensure the systems’ stability, countermeasures may be required to avoid development of highly resistant, adapted microorganisms, and a complete loss of microbial [germ} diversity,” she said.

The crew was the main source of human-associated bacteria within the habitat, but the prolonged confinement seemed to have the most significant effect on the bacterial community, the researchers found.

The study authors suggested their findings provide insight on habitat maintenance and could help scientists develop strategies to ensure a healthy environment for astronauts during future deep space missions.

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