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A clump of Staphylococcus epidermidis bacteria (green) in the extracellular matrix, which connects cells and tissue, taken with a scanning electron microscope. At right, the bacterium Enterococcus faecalis, which lives in the human gut, is just one type of microbe that live on your skin, up your nose, in your gut; enough bacteria, fungi and other microbes that collected together could weigh a few pounds. (AP Photo/National Institute of Allergy and Infectious Diseases (NIAID, Agriculture Department)

Could antibiotics make you fat?

Two studies this week suggest that using antibiotics may save people’s lives, but could also change their metabolisms. Put together, the studies suggest that taking antibiotics might alter digestion to help people absorb calories from food they normally would be unable to digest.

Every human carries pounds of microorganisms that we couldn’t live without. They break down food and extract nutrients like Vitamin K for us. Antibiotics will kill some of these beneficial organisms, which is why so many doctors now tell patients to eat yogurt after taking a course of the drugs, to replace some of the good guys.

“There is emerging evidence suggesting the importance of the microbes in our intestines and their role in absorbing food,” said Dr. Leonardo Trasande of New York University, who led one of the studies.

The two studies look at different sides of the coin, and help answer two questions -- whether antibiotics really do affect how we absorb nutrients, and how they might do so. Together, they support the idea that the drugs kill off some populations of bacteria and allow microbes to flourish that are very good at getting calories out of hard-to-digest plant foods.

Trasande’s team looked at the medical records of more than 11,000 newborns in Britain, who were carefully followed after they were born in the 1990s. The babies who got antibiotics before they were 6 months old were 22 percent more likely to be overweight by the time they were 3 years old, the team reported in the International Journal of Obesity. If they got antibiotics later in childhood, there wasn’t a strong effect – something that could suggest the antibiotics changed the balance of the microbes as they were just setting up shop in the infants. Babies are born with sterile digestive tracts, and they acquire bacteria, yeast and other microorganisms mostly from their mothers. The germs are collectively called “flora” by scientists.

“They play key roles in immune functions, among other things,” Trasande told NBC News. “Antibiotics disrupt the development of the healthy flora in our gut. The earlier the exposure occurs, the more disruptions occur,” Trasande says. “It seems the first few days and months are important. It is difficult to reconstitute that in later life.”

The other piece of the puzzle is whether it’s the antibiotics or something else that is doing this. Dr. Martin Blaser of New York University has been studying the effects of antibiotics on the body for years. A second team he heads has been studying what happens if you feed antibiotics to animals.

They wanted to replicate what farmers have known for decades -- that giving low doses of antibiotics to farm animals make them fatter. Many experts had thought the drugs were keeping the animals from getting infections and making them healthier, but Blaser suspected something else was going on.

When his team gave mice low doses of antibiotics long-term, the mice got fatter even though they weren’t eating any more than other mice. This, they report this week’s issue of the journal Nature, suggests the antibiotics somehow make the mice absorb more calories from their food.

“We have other work that is in process that continues to confirm and extend this,” Blaser said. “That work shows that giving antibiotics early in life, similar to what farmers do in their farm animals, is changing metabolism in mice and making them bigger and fatter.”

The gastrointestinal tract is also the center of hormone production, the researchers said. It’s possible altering the organisms in the intestines – called the microbiome -- could help people better absorb nutrients and calories from “indigestible” foods such as cellulose.

The second NYU team gave the mice varying combinations of the antibiotics penicillin, vancomycin and chlortetracycline. Mice that got the antibiotics piled on more fat than other mice, even though the fatter mice did not eat more. Also, their poop had fewer calories – suggesting they were absorbing more and eliminating less.

Other mouse studies being done by Blaser’s team show that giving antibiotics to mice every once in a while -- akin to giving antibiotics to a child to treat ear infections -- also alter the gut bacteria.

So does that explain why people are getting fatter? Does every dose of antibiotics kill off some bacteria, allowing the energy-efficient species to move in and squeeze every calorie out of an apple peel or bowl of high-fiber cereal?  

“That’s at least one of the mechanisms,” says Blaser. But he notes that studies in people suggest it’s doses very early in life that matter most, just as various colonies of bacteria are getting established in the colon and intestines. And there’s an effect on the immune system, too. Other studies show that changing the balance of bacteria effects immune cells known as T-cells – something that may someday help explain links between diet and diseases such as inflammatory bowel diseases and perhaps even colon cancer.

In other words, it is too soon to say whether a 5-day prescription of Zithromax for strep throat could make you fat.

“A lot of things are interconnected,” Blaser says. “Obesity is multifactorial. I am not saying antibiotic effects on the microbiome are everything but our work suggests it is contributory. Whether it’s 10 percent or 70 percent, we don’t know yet.”

Another big missing piece of the puzzle: Which species of bacteria are the most important? People have trillions of bacteria in and on their bodies. Microbes outnumber human cells by a factor of at least 10 to one and scientists believe at least 10,000 different species live in and on us. Healthy colonies of microbes not only process vitamins, but maintain pH balance on the skin, prevent tooth decay and even protect against infections. So which ones are killed by the antibiotics, and which do we want more of? No one knows yet.

“We are just beginning to scratch the surface,” said Dr. Ilseung Cho, who worked on the study in mice.

While it is important not to use antibiotics when they are not needed, the researchers stress that they do save lives. “I wouldn’t rush to come off any antibiotics right now,” Cho cautioned.

It’s also not clear if food like yogurt, called probiotics, help much. “There is a concept called prebiotics,” Cho said. “It is essentially introducing nutrients into your digestive tract that would select for particular bacteria. Then you might be able to alter the bacteria.”

Prebiotics are found in plain old food such as soybeans, jicama and raw oats, all of which are rich in compounds such as inulin, which people cannot digest, but which certain bacteria love.

Related links:

• Mapping one man's microbes
• Bacteria affect mood
• Ruled by your gut

Crusader / featurepics.com

Do you really want to touch the remote? A small study of hotel rooms in three states found that the main light switch and the TV remote were two surfaces most contaminated with bacteria.

Next time you enter a new hotel room, you might think twice before touching the light switch or reaching for the remote.

Those are two of the top surfaces most likely to be contaminated with potentially sickening bacteria, according to a small new study aimed at boosting cleaning practices at the nation’s hotels and motels.

Katie Kirsch, a University of Houston researcher, led a team that measured germs on everything from curtain rods to bathroom sinks in nine hotel rooms in three states.

Kirsch came away thinking that the current industry standard of visual assessment -- if it looks clean, it is clean -- isn’t good enough.

“A visual assessment can’t tell you about bacteria and viruses,” she told msnbc.com. “It can tell you what’s on the surface, but not if it’s been disinfected.”

Kirsch, a recent graduate who has also studied subjects like the pathogens that linger on restaurant menus and the cleanliness of public bathrooms, enlisted colleagues at Purdue University and the University of South Carolina. They’re presenting their work Sunday at the annual meeting of the American Society for Microbiology.

The researchers went looking for aerobic bacteria, which include germs known to cause illness, including streptococcus and staphylococcus. They also tested for coliform -- or fecal -- bugs. They swabbed the surfaces, put the samples on ice and then flew them to the University of Houston microbiology lab for analysis.

Top hot spots for aerobic bacteria in hotels turned out to be the bathroom sinks and floors, the main light switches and the TV remotes. The remotes, for instance, racked up a mean of 67.6 colony-forming units of bacteria, or CFU, per cubic centimeter squared.

For comparison, one study of environmental cleanliness in hospitals recommended a top limit of 5 CFU per cubic centimeter squared. Even using Kirsch’s relaxed proposal of 10 CFU, the TV remotes racked up way too many bugs.

The main light switches in the rooms were worse, with a mean of 112.7 CFU for aerobic bacteria. Even the telephone keypad was icky, with 20.2 CFU.

When it came to fecal bacteria, the main light switch was the most serious surface offender, with 111.1 CFU.

That may sound disgusting, but it doesn’t necessarily mean hotel surfaces will make you sick, emphasized Kirsch, who said that her study wasn’t designed to test for the specific pathogens that cause illness.  Her supervisor underscored that it shouldn’t keep people from staying in hotels.

“It’s not a scare thing,” said Jay Neal, an assistant professor in the Conrad N. Hilton College of Hotel and Restaurant management.

Instead, Kirsch was conducting baseline research that she hopes might one day inspire the hotel industry to adopt cleaning and sanitation guidelines invoked through HACCP -- Hazard Analysis and Critical Control Points -- a protocol already used by food and healthcare industries.

“The study is aimed more toward the housekeeping managers,” she noted.

In addition to checking for the bugs on surfaces in the hotel rooms, the researchers also swabbed for bacteria on the gloves, mops and sponges used by cleaning staff, which have the potential to carry germs from room to room.

Those items were crawling with all kinds of bacteria: at least 500 CFU of aerobic and fecal bacteria on the sponges, for instance.

“When you’re in a hotel room, there’s that stranger factor,” said Neal, noting that no one wants to inherit fecal bacteria from the guy down the hall.

Some hotels appear to be getting the message. Best Western hotels, for instance, just launched a campaign to equip its housekeepers with black light testers to detect unseen bugs. They’re even offering a sanitary wrap for the remotes.

Hampton Inns have launched a campaign emphasizing cleanliness with commercials featuring a hotel guest dressed in a Hazmat suit.

Meanwhile, ordinary guests fearful of hotel germs can take matters into their own hands, said Kirsch, who agreed traveling with sanitizing wipes is an option:

“It would make consumers feel better to wipe down the surfaces.”

 Related stories from Vitals:

• Man's microbes help map 'normal' in humans
• Buggy break rooms: Study reveals office ick
• Half of hospital rooms rife with drug-resistant bugs, study finds

Kimberly-Clark Professional

Half of the microwave door handles in office break rooms are tainted, found a new study that examined 5,000 swabs taken from from offices.

Your co-workers may seem friendly but, if a study released today is any indication, they could be aircraft carriers for germs.

According to University of Arizona microbiologist Charles Gerba, who researches the environmental presence of infectious bacteria and viruses, employees in offices arrive in the morning, “put their stuff on their desks” where, he says, the germ payload is often more than you’d find on the typical toilet seat, “and then go to break rooms to get coffee. The two things you spread in a break room are office gossip and germs.”

Gerba consulted on the new study, conducted by a division of the Kimberly-Clark Corporation (which manufactures and sells cleaning and disinfectant supplies to businesses). For the study, researchers collected nearly 5,000 swabs from office buildings containing almost 3,000 employees over the course of two years to measure traces of possible contamination on office surfaces.

The study, which focused on office break rooms, found that 75 percent of break room faucet handles displayed a high degree of contamination as did nearly half of microwave oven handles, and a quarter of refrigerator door handles.

“The break room is really the center of germ transfer in the office rather than the individual cubicle," said Gerba. "Everything is shared in the break room.”

For example, he pointed out, many people rinse their coffee cups and push a sponge around the inside. Those sponges can be loaded with E. coli, “so you’re really wiping your mug with E. coli,” he said.

The second big break room habit that spreads germs is greeting co-workers. “Actually,” Gerba, explained, from a pathogen-transfer perspective, “you’d be better off kissing each other than shaking hands” because people cough or sneeze into their hands and transfer the germs when shaking.

In earlier work, Gerba documented that each person’s desktop environment is rife with germs like norovirus (which can cause diarrhea), parainfluenza (respiratory tract infections), and drug-resistant staph (MRSA).

The Kimberly-Clark study did not measure viruses and bacteria directly. It measured ATP, adenosine triphosphate, present in all organic matter. The presence of ATP means a surface contains some form of organic material, which could indicate either the presence of bacteria and viruses, or that something such as food residue is present that could provide a welcoming environment for germs.

The company has an obvious incentive to make workplaces sound germy, but, according to Gerba, they really are. “Those break rooms are as bad as we thought they were,” he said.

This doesn’t mean your office break room is necessarily a biohazard zone, or that you’re bound to get sick if you use it. It just means that any surfaces people touch are likely to be contaminated with something.

A simple solution, Gerba pointed out, is for companies to clean more carefully, and for employees to wash their hands, or use a hand sanitizer, more often. 

Read more:

The dirtiest places -- and how to clean them up 
E. Coli found on 50 percent of shopping carts
Reusable grocery bag carried nasty norvirus, scientists say

Brian Alexander is co-author, with Larry Young Ph.D., of "The Chemistry Between Us: Love Sex and the Science of Attraction," to be published Sept. 13.

featurepics.com

A resuable grocery bag was traced to an outbreak of norovirus that sickened members of a girls' soccer team in Oregon.

Oregon public health officials have traced a nasty outbreak of norovirus infections in a group of soccer players to an unlikely source: a reusable grocery bag contaminated with what some experts are calling “the perfect pathogens.”

The incident is raising questions, once again, about the cleanliness of the portable shopping bags that many consumers use to avoid the paper vs. plastic impact on the environment.

“We wash our clothes when they’re dirty; we should wash our bags, too,” said Kimberly K. Repp, an epidemiologist with the Washington County Department of Health and Human Services in Hillsboro, Ore. Her work is published this week in the Journal of Infectious Diseases.

Repp was an intern with the Oregon Health and Science University in October 2010 when she and other experts were asked to help unravel the mystery of sick soccer players and their chaperones. They had traveled north from Beaverton and Tigard, Ore., to Washington state on a Friday for a weekend tournament.

Less than 48 hours later, nine people were ill with unpleasant symptoms including vomiting and diarrhea. The question was: How did they get it?

One of the soccer players --  all 13- and 14-year-old girls -- had fallen ill on Saturday night and moved into the room of one of the parent chaperones. The pair went home early Sunday, with no further contact with other players.

Even so, seven other people became ill within days, stumping scientists momentarily.

CDC

Noroviruses are a group of viruses responsible for some 21 million cases of gastrointestinal illness a year, including 70,000 hospitalizations and 800 deaths.

“It involved really thinking outside the bag, so to speak,” Repp said.

Eventually, interviews revealed that most of those who became ill ate packaged cookies at a Sunday lunch. Where did the cookies come from? Turns out, the culprit was a reusable grocery bag of snacks left in the empty hotel room occupied by the first girl who got sick.

Quickly, the puzzle fell into place. The girl had been very ill in the hotel bathroom, spreading an aerosol of norovirus that landed everywhere, including on the reusable grocery bag hanging in the room.

When scientists checked the bag, it tested positive for the bug, even two weeks later.

“It was a knock out of the park,” said Repp. “We demonstrated norovirus transmission without person-to-person contact. That’s why this is different.”

The trouble with noroviruses -- which cause an estimated 21 million cases of gastroenteritis a year, some 70,000 hospitalizations and 800 deaths -- is that they’re tough bugs that can live for prolonged periods on objects and surfaces, said Dr. William Schaffner, chairman of the department of preventive medicine at Vanderbilt University Medical Center in Nashville.

“Norovirus does have the vexing capacity to persist in the environment,” he said.

While the risk of contracting an illness from any particular reusable bag is low, Schaffner said, the Oregon study follows a 2010 paper by researchers at the University of Arizona and Loma Linda University that found large numbers of bacteria in reusable grocery bags, including 12 percent that were contaminated with E. coli.

When scientists stored the bags in the trunks of cars for two hours, the number of bacteria jumped 10-fold.

Some critics dismissed that study, which was funded in part by the American Chemistry Council, which supports the makers of some disposable plastic bags.

But few have debated the study’s conclusion, which found that washing the reusable shopping bags regularly decreased contamination by 99.9 percent.

“You could just wipe it down with Lysol or Clorox,” said Repp.

Schaffner agrees. The most important tool to prevent norovirus, which spreads rapidly and infects quickly, is good hygiene, including careful hand-washing and thorough cleaning of the contaminated environment.

“You could wash the bag,” Schaffner said. “Or you could start over with a new bag."

Related stories:

Video: Norovirus nightmare on cruise ships

Mystery sapovirus strikes nursing home, researchers say

Norovirus vaccine showing promise

Deaths from stomach flu have doubled since '99