TIME Pregnancy

The New Way to Predict When Pregnant Women Will Deliver

All images by Bettina Bhandari—Getty Images/Flickr RF

For clues to the due date, doctors may check your bacteria

There’s growing interest in examining things we can’t even see in order to better understand our health. Millions of bacteria make our bodies their home and most of them are not of the disease-causing kind. Instead, they’re helpful—so-called “good bacteria”—and researchers are finding ever new and strange ways that our bacterial makeup may predict our health.

Researchers led by Dr. Kjersti Aagaard at the Baylor College of Medicine and Texas Children’s Hospital found that the placenta contains clues about when a pregnancy will end. Aagaard is not ready to say that the bacteria living there actually decide when moms-to-be will give birth, but the association is strong enough to make it worth studying further.

MORE: The Good Bugs: How the Germs in Your Body Keep You Healthy

She and her team collected 320 placentas from women who delivered pre-term (at 34-37 weeks), or at term, within an hour of delivery. They analyzed the tissues for the microbes inhabiting them, and compared what they found there to samples the women provided from other regions as well, including the mouth, nose, vagina, gut and skin.

They found that the makeup of the placenta microbial community was different between the pre-term and term groups. “We’re not suggesting that the differences in the placental microbiome necessarily cause pre-term birth; we don’t know,” says Aagaard. “All we know is that they are different.” At this point, they can only guess that the varying communities of bacteria have different functions, and these affect both the placenta’s ability to nurture the fetus and the development of the fetus itself.

MORE: The Latest Thing in Pills? Ones Made From Poop

Looking ahead, Aagaard says that even if a specific bacterial composition in the placenta appears to cause early delivery, it’s not practical nor safe to sample the placenta throughout pregnancy to find out. More benign would be sampling the bacterial makeup in the mouth, which are similar to those in the placenta, suggesting that down the line, a mouth swab may provide the same information.

“By focusing on oral health, we may actually be optimizing the health of the pregnancy and limiting the risk of pre-term birth,” says Aagaard. After paying so much attention to the more obvious ways to make a pregnancy healthy, it may be time to consider the less obvious – and less visible ones.

TIME Weight loss

Can the Paleo Diet Help You Lose Weight?

Modern day version of a paleo diet meal Lauren Barkume—Getty Images/Flickr Open

Scientists tested the hyped diet in a lab. Here's what they found

For weight loss, the paleo diet, which is what our ancestors ate when they had to hunt or gather their food instead of growing it, seems like a good idea. It’s high in protein and fiber—and anyone who’s ever tried to lose weight has been told that the secrets to slimming down are protein and fiber, which take longer to transit down the digestive system making us feel fuller longer. Processed carbohydrates, on the other hand, zip through our system making us hungry seeminly minutes after we’ve put down the fork.

The high-fiber part, paleo diet devotees maintain, is the key. Because fiber is bulkier and harder to digest, it serves as an appetite suppressant by effectively turning off hunger signals. Except that’s not what scientists found when they put the ancient paleo diet to the test—in a test tube.

MORE: The Paleo Diet Craze: What’s Right and Wrong About Eating Like a Caveman

Gary Frost, from Imperial College London, and his colleagues wanted to confirm how our Paleolithic ancestors addressed their energy needs. So they took fecal samples, full of the gut microbes that are known to digest and break down foods, from three grass-grazing baboons (who ate similarly to the way human ancestors did) as well as from three human subjects. They then added digested solutions of either a grass-based diet or a potato-heavy one to each, to see how the composition of the bacteria changed in response to the food.

They expected that the baboon samples with the grass-based diet would produce the highest amounts of appetite-suppressing hormones, thanks to the bulky nature of the grass. Instead, they found that the potato-based diet produced higher levels of these hormones. Frost says that makes sense, since grasses aren’t very high in nutrients or energy, so our ancestors would have had to graze pretty constantly throughout the day in order get enough from the grass. But that’s in a test tube and based on the actual way Paleolithics ate. What about the modern paleo diet? Should you ditch the promise altogether?

MORE: Overcoming Obesity

No. The modern paleo diet likely, however, does do a much better job in keeping appetite in check.

The kind of grasses our ancestors ate contain insoluble fibers that the body doesn’t break down much, so they may not trigger appetite suppressing signals of other kinds of fiber. That doesn’t mean insoluble fiber isn’t good for you; it is. It’s what’s in leafy greens, some fruit, and lots of vegetables. But it doesn’t send your brain the satiety signal the way soluble fiber does. Soluble fiber, however, is metabolized by the body to produce compounds that set off the signal to the brain that the body has had enough.

The bottom line? All fiber is good fiber, but if you’re trying to lose weight or control cravings, make sure you’re getting plenty of the soluble kind, which can be found in a healthy modern paleo diet. Think: lentils and beans, fruit, nuts, flaxseeds, cucumbers, celery, and carrots.

If you want to eat your way to a satisfied (and suppressed) appetite, a protein and soluble-fiber rich diet may be the way to go.



Here’s Why Bacteria Like E-Cigs

Barbara Rich—Getty Images/Flickr Open

The vapor from e-cigarettes is supposed to be safer than cigarette smoke, but not when it comes to fighting bacteria

There’s quite a bit that we still don’t know about e-cigarettes when it comes to how safe they are — if they cause lung cancer like traditional cigarettes do, whether they are as addictive as cigarettes, and more. That’s reflected by the fact that fewer smokers believe that e-cigs are safer for their health than traditional cigarettes; in 2010, 85% did, but that percentage dropped to 65% in 2013, according to a study published in the American Journal of Preventive Medicine.

But for bacteria, e-cigs may not be so bad. Dr. Laura Crotty Alexander, from the University of California at San Diego and the VA San Diego Healthcare System, found that the vapor from e-cigs prompts bacteria to become more resistant to antibiotics. In the presence of e-cig vapor, for example, methicillin resistant staphylococcus aureus (MRSA) became more resistant to the natural anti-microbial agents that the body makes. Cigarette smoke also produces the same effect, but Crotty Alexander was surprised that the e-cig vapors did as well, given that they were not supposed to contain the health-harming carcinogens that tobacco smoke does.

MORE: The FDA Plans to Ban E-Cigarette Sales to Minors

“I was hoping that maybe e-cigarettes would be safer and that they would not stress the bacteria as much as cigarette smoke,” she says of her findings, which she presented at the American Thoracic Society International Conference. “But we found that the e-cig vapor also made bugs become more resistant to killing by antimicrobial peptides.”

Other studies show that these peptides, known as the body’s natural antibiotics, are structurally similar to antibiotic drugs, so while Crotty Alexander did not test bacteria exposed to e-cig vapor against antibiotics, she expects they would be resistant to the medications as well.

MORE: Study: E-Cigarettes Do Not Help People Quit Smoking

How did the bugs fight back? When stressed by the e-cig vapors to defend themselves, the bacteria produced copious amounts of biofilm, a sticky, slimy polymer that acts as their armor against things like antibiotics.

But the vapors may be doing much more than disturbing the bacteria. Earlier studies showed that traditional cigarette smoke, with its tar and tobacco-burning byproducts, can also weaken the ability of the body’s immune cells to defend against the insult, making it harder to fight off infections. Crotty Alexander is starting to analyze human cells to see if e-cig vapors have the same effect. She’s narrowing down which components of e-cigs contribute to the antibiotic resistance – some e-juices are made with propylene glycol, while others contain a vegetable-based glycol, and not all contain nicotine.

MORE: E-Cigs Still Produce Carcinogens, Study Shows

So far, it looks like the nicotine may be driving the MRSA biofilms, but Crotty Alexander is doing more research to determine how e-cigs are affecting human immune cells. As the survey of smokers shows, however, they may already know the answer.

TIME mrsa

Bacteria Thrive For Days On Airplanes

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You’re not the only one squeezed into that airplane seat – you’ve got lots of invisible company

Every time you take your seat on an airplane flight, you’re traveling with some hidden companions, courtesy of the passengers (or more likely the passengers) who came before you.

No surprise that airline cabins, from the seats to the seat pockets and the tray tables and lavatories, are blanketed with germs. Here’s a scary fact – the average human loses 30,000 to 40,000 skin cells every hour, and our skin is covered in bacteria – some of which are harmful. An estimated 1% to 2% of people in the U.S. may be carriers of methicillin resistant staphylococcus aureus (MRSA), for example, which can produce sores on the skin and be life-threatening if it enters the bloodstream, many without showing any symptoms. So imagine what you leave behind on a transcontinental flight. But can those discarded cells make you sick?

MORE: Antibiotic Resistant Genes Are Everywhere, Even in Arctic Ice

The first step to answering that question is figuring out if the microbes can actually survive long enough in a plane cabin for unwitting passengers to get infected. And researchers at Auburn University confirmed that yes, the bugs are pretty good at making practically every surface in a plane their home. Kiril Vaglenov, a post doctoral fellow in materials engineering, and his colleagues did what most of us wish we could before every flight – in the lab, they sterilized six surfaces normally found in a cabin, from the seats to the toilet handles by irradiating them with gamma radiation. Then they did something none of us would – they intentionally infected these surfaces with some unwelcome bugs – MRSA and E. coli 0157, which causes severe diarrheal disease.

MRSA found the seat pocket material a particularly cozy habitat, surviving for as long as 168 hours there, while E. coli preferred the rubber armrest, where it lived for up to 96 hours. But the most hospitable surfaces for keeping the microbes alive weren’t necessarily the most dangerous ones for picking up the bugs. Vaglenov used pig skin as a proxy for human hosts (who wants to intentionally exposed themselves to MRSA or E. coli?) and used simulated saliva and sweat solutions containing the microbes. He found that the more porous the surface, the longer the bacteria survived, and the lower their ability to infect, since the microbes tended to burrow deep in the threads and pores of the material. So the non-porous metal flush button in the bathroom, for example, was more likely to transmit microbes than the seat pocket, even though bacteria could survive longer in the seat pocket. Here’s the breakdown of the germiest surfaces in the cabin:

  • Seat pocket 8 days
  • Rubber arm rest 7 days
  • Leather seat 7 days
  • Plastic window shade 3 days
  • Plastic tray table 3 days
  • Steel toilet handle 2 days

“The findings are potentially a call to arms for the airline industry who may wish to take a page from the healthcare industry and apply cleaning products or use antimicrobial fabrics in the cabin,” says Michael Schmidt, professor of microbiology and immunology at the Medical University of South Carolina who studies antimicrobial strategies and was not involved in the study.

MORE: Science Confirms Dollar Bills Are Covered in a Bajillion Gross Germs

The lesson? Just as they do in hospitals, where they can live for up to a year, bacteria are quite at home in a plane. Which means that they can easily jump from a tray table to a passenger and cause disease. “If the bacteria do not survive there is no transmission,” says Vaglenov, who presented the results at the annual meeting of the American Society for Microbiology. “And there is no infection if the bacteria are not transmitted in an viable state. We found they survive and they are viable.”

MORE: What You Need to Know About Staph

In this study, he did not test the levels of the bacteria after the disinfection that airlines do, but he plans to do that using less dangerous strains of microbes, and human subjects, in future studies.

In the meantime, he says, it makes sense for the airline industry to consider whether different sanitation strategies are needed to protect passengers. Hospitals use peroxide vapors or ultraviolet light to penetrate fabrics found in furniture to ferret out microbes, for instance. As the cruise industry learned with the norovirus, microbes are quite good at turning confined spaces packed with inviting human hosts into a playground of infection.


Pancreatic Cancer Set to Become Second Most Fatal Cancer

It’s already responsible for more deaths than prostate cancer, and by 2030 it will be second to only lung cancer in cancer related deaths

By 2030, more people will be diagnosed with breast, prostate and lung cancers than with pancreatic cancers, but more pancreatic cancer patients will die of their disease, according to a paper in the journal Cancer Research.

MORE: The Pancreatic Cancer That Killed Steve Jobs

Rates of pancreatic cancer are increasing, in part because of the aging population, and in part because of rising rates of type 2 diabetes, which results in some cases when pancreatic islet cells become less efficient at producing insulin. Unlike breast, prostate and colon cancers, which have effective screening methods, there are no strong, reliable ways to detect pancreatic tumors because the organ lies so deep inside the body. That explains why the death rate for the disease is so high; most cases are not diagnosed until the advanced stages, when surgery and other treatments are no longer effective.

Death rates from pancreatic cancer may also rise in prominence because mortality from other cancers are dropping, says Lynn Matrisian, vice president of scientific and medical affairs at the Pancreatic Cancer Action Network.

There is hope that a blood test for pancreatic tumors may detect the disease at an early stage; researchers from the University of Texas MD Anderson Cancer Center reported at the American Association for Cancer Research special conference on pancreatic cancer that a panel of four markers in the blood successfully distinguished people with early pancreatic cancer from those with benign pancreatic cysts. And scientists at Stanford University identified a protein that pancreatic and other tumors use to protect themselves from being eliminated by the body’s immune system. They say that a drug targeting this protein, CD47, successfully shrunk pancreatic tumors in mice and they plan to study the drug in human trials this summer.


Poor Sleep Affects Babies’ Weight Later In Life

Lauren Burke—Getty Images

Sleep-deprived babies may grow up to be heavier kids, according to the latest research

Plenty of studies connect poor sleep habits in adults to obesity, but few track the long term effect of infants’ sleep throughout childhood. That’s why Dr. Elsie Taveras, chief of general pediatrics at Massachusetts General Hospital for Children, and her colleagues followed babies every year from 6 months old until they were 7. At each visit, the team recorded height, weight, body fat, waist and hip circumference and sleep habit information to get the most complete picture yet of how sleep patterns are connected to childhood health.

MORE: It’s Time to Pay Attention to Sleep, the New Health Frontier

Taveras rated the children’s sleep according to the recommended amounts for their age group set by the National Sleep Foundation and the National Heart, Lung and Blood Institute—for those under 2, that was more than 12 hours a day; for 3-4 year olds, that was more than 10 hours a day; and for kids 5 to 7, that was more than nine hours daily. At age 7, children with the lowest sleep scores throughout their young lives had the highest rates of obesity and body fat, specifically abdominal fat which other studies have linked to a higher risk of chronic conditions such as heart disease and diabetes.

What sets Taveras’ work apart is that it shows how consistently disrupted sleep throughout childhood can have a cumulative effect on health. “This lends more evidence to the fact that insufficient sleep has significant health implications,” she says.

MORE: Please, Please Go to Sleep

Consistently skimping on shut-eye, especially at an early age, may interfere with appetite hormones that control how hungry and full we feel. And because sleep is an important time for the body’s metabolism to reset itself, sleep deprivation can also skew the body’s circadian clock, changing the body’s ability to burn calories from the diet and leading to higher blood sugar levels.

The findings strengthen what’s known about the importance of sleep in keeping the body’s metabolism running smoothly, but for the youngest children, it also highlights the critical role that parents play in establishing healthy sleep habits. “Household routines, such as bed times and meal times, can be important for getting enough sleep,” says Taveras. “I usually say three things to parents who are worried about their children’s sleep—implement consistent routines around bed times and meal times; reduce the amount of caffeinated beverages they drink during the day; and eliminate high tech distractions from their bedrooms.”


We Trust Strangers, Even When It Doesn’t Make Sense to Do So

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There’s a reason why those bank scams on the internet continue to flourish. Because we feel guilty if we don’t trust people

Relationships, businesses, governments—almost every interaction people have is built on trust. eBay can’t survive without it. But why do we put so much faith in others? What makes us so sure that the person who puts a mint condition baby carriage up for sale a) Actually owns the carriage, b) Isn’t lying when he says it’s in mint condition, and c) will send the said carriage when you pay him?

David Dunning, a psychology professor at Cornell University and his colleagues, say that all rational behavior theories predict that people shouldn’t trust complete strangers. We have no way of knowing that the other person will do what he promises in any transaction, because we know nothing about that person. Any rational model of behavior predicts that the other person will renege on any promise as soon as it’s in his best interest to do so. Survival of the fittest and all.

But in a series of trust experiments with 645 undergraduates, the scientists found that 62% would give away a small sum of money even if their two options were that the other person would keep it all, or, if the person decided to return it, that both would get back a larger amount. If the students were actually calculating the odds of getting their money back or increasing it, only 20% would have taken the gamble.

MORE: Faith in Humanity: 10 Studies to Restore Your Hope for the Future

What does that tell us about ourselves? That we’re more of a society than we thought. Most of the participants talked about politeness and rudeness as motivating them to trust their fellow study subject, even if it meant potentially getting exploited by them. “Their behavior was a comment on the other person’s character,” says Dunning. By not giving up the money, in other words, the volunteers were concerned that they would be implying that the other subject was untrustworthy and a crook, because by keeping the money, they had decided it wasn’t going to be returned. “People feel a social duty to respect the other person,” says Dunning.

How does he know that the first person wasn’t simply acting out of greed over potentially quadrupling their payoff? Through other variations of this game, in which participants chose between trusting a stranger to return the money or a coin flip that would decide, people did not take such gambles on getting their money back if they were told the coin flip would determine whether they got their money back. “That tells us that people are responding to issues in the other person’s character,” says Dunning. “The signal they are sending is that ‘I respect your character.’ As soon as you take out that issue, people gamble at the rate that would be consistent with greed.”

You can interpret that as either being a sign of solidarity, an inexplicable sense of belonging to and being a member of a community in which everyone treats everyone with respect, or you can view it in a slightly more cynical way – that people trust others because they think they have to, and are guilted into acting in the more magnanimous way. Different people may justify their behavior in different ways, says Dunning. That’s because although most people will act in the more generous, way that shows respect and trust for their fellow man, that doesn’t mean that they believe internally that everyone is trustworthy. “The situation causes internal conflict,” he says. “We get 30% to 40% of people saying something like the odds are that I am going to get screwed, or not get the money back, but they still give up the $5 to the other person.”

That strength of community norms, or an obligation to act in ways that may be counter to their internal beliefs, is something that Dunning hopes to explore further. Does it come from an even deeper faith in the goodness of the world and an optimism that people are good and nice to each other? Perhaps. For now, it’s enough to know that even strangers tend to trust one another – even if it’s driven by a sense of obligation.


Some People Are Wired to Want More Sex, Brain Study Shows

If it were an app, it would be worth millions. Here’s the best way to tally up how many sex partners a paramour has had in the past year

It turns out that some people are actually wired to have more sex—or at least be really, really motivated to hook up.

Research from the University of California Los Angeles and published in the journal Social Cognitive and Affective Neuroscience shows, thanks to an old fashioned brain recording, EEG-style, that some people’s brains are simply more sensitive to sexual cues than others — which means it takes less to get them aroused and ultimately leads them to find sexual partners.

MORE: How Changing Your Birth Control Can Make Sex Worse

Nicole Prause, an assistant research scientist in psychiatry at University of California Los Angeles, and her colleagues recruited psychology students to get an electroencephalogram of their brains and to view 225 standardized pictures of pleasant, neutral or unpleasant things. The pleasant images included sexually stimulating ones and these ranged from PG stuff like people kissing to more explicit pictures of people having sex. The students were also asked about their number of sexual partners in the past year.

Some of the participants showed strong reactions on the EEG to nearly all of the intimacy-themed images, regardless of whether they were explicit. And these were the same people who reported having more partners. Prause says the EEG is a good measure of how motivated the brain is – stronger responses typically occur when we’re faced with new and unfamiliar things, for example. In this case, the sexual cues are motivating for some.

It turns out that men and women were equally like to fall into this category; Prause’s team did not find any gender-based differences in the EEG patterns.

Does that mean some people are wired to be addicted to sex? Prause isn’t willing to go that far. “People may be more sensitive to sexual cues and engage in behaviors that aren’t helpful for them, but this study suggests you don’t need to use the label of addiction to describe that,” she says. For these people, it’s not a chasing of a “high” or a reward, but a biological sensitivity to sexual cues that sets their arousal threshold at a much lower level.

MORE: Why Science Needs More Sex

But before you track down the nearest EEG lab, Prause says the purpose of the study wasn’t to suss out the promiscuous among us. Because the EEG reading is a measure of motivation, understanding that some people’s sexual activity is a function of their biologically guided arousal should help in understanding risky sexual behavior and finding better ways to intervene.

“Being aware that if you are going out, and there is the possibility of having a new partner, and thinking about ways to not get too excited may sound silly, but managing that rather than ignoring it may help with better ways to control risky sexual behavior,” she says. We may be wired to want sex, but that doesn’t mean the wiring can’t be re-routed.


The Best Help for Alcoholics Is One We’re Not Using


There’s a drug treatment for alcoholism, but few are taking advantage of it.

Naltrexone, which has been used for years to help alcoholics avoid relapsing, isn’t as widely used as it should be, say some addiction experts. The reason? Many of the studies that show it can be effective in helping alcoholics to avoid returning to drinking have been conducted with those who were also getting behavior therapy and counseling. So it’s hard to know how much the drug is helping to keep these patients sober.

But a growing number of doctors are looking at naltrexone not as a cure for alcoholism, but as an ally in helping alcoholics to calm their cravings so behavior therapy and counseling, which equip patients with skills to manage their addictions over the long term, can be more effective.

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