More than half your body is not human

More than half of your body is not human, say scientists.

Human cells make up only 43% of the body's total cell count. The rest are microscopic colonists.

Understanding this hidden half of ourselves - our microbiome - is rapidly transforming understanding of diseases from allergy to Parkinson's.

The field is even asking questions of what it means to be "human" and is leading to new innovative treatments as a result.

"They are essential to your health," says Prof Ruth Ley, the director of the department of microbiome science at the Max Planck Institute, "your body isn't just you".

No matter how well you wash, nearly every nook and cranny of your body is covered in microscopic creatures.

This includes bacteria, viruses, fungi and archaea (organisms originally misclassified as bacteria). The greatest concentration of this microscopic life is in the dark murky depths of our oxygen-deprived bowels.

Prof Rob Knight, from University of California San Diego, told the BBC: "You're more microbe than you are human."

Originally it was thought our cells were outnumbered 10 to one.

"That's been refined much closer to one-to-one, so the current estimate is you're about 43% human if you're counting up all the cells," he says.

But genetically we're even more outgunned.

The human genome - the full set of genetic instructions for a human being - is made up of 20,000 instructions called genes.

But add all the genes in our microbiome together and the figure comes out between two and 20 million microbial genes.

Prof Sarkis Mazmanian, a microbiologist from Caltech, argues: "We don't have just one genome, the genes of our microbiome present essentially a second genome which augment the activity of our own.

"What makes us human is, in my opinion, the combination of our own DNA, plus the DNA of our gut microbes."

Listen to The Second Genome on BBC Radio 4.

Airs 11:00 BST Tuesday April 10, repeated 21:00 BST Monday April 16 and on the BBC iPlayer

It would be naive to think we carry around so much microbial material without it interacting or having any effect on our bodies at all.

Science is rapidly uncovering the role the microbiome plays in digestion, regulating the immune system, protecting against disease and manufacturing vital vitamins.

Prof Knight said: "We're finding ways that these tiny creatures totally transform our health in ways we never imagined until recently."

It is a new way of thinking about the microbial world. To date, our relationship with microbes has largely been one of warfare.

Microbial battleground

Antibiotics and vaccines have been the weapons unleashed against the likes of smallpox, Mycobacterium tuberculosis or MRSA.

That's been a good thing and has saved large numbers of lives.

But some researchers are concerned that our assault on the bad guys has done untold damage to our "good bacteria".

Prof Ley told me: "We have over the past 50 years done a terrific job of eliminating infectious disease.

"But we have seen an enormous and terrifying increase in autoimmune disease and in allergy.

"Where work on the microbiome comes in is seeing how changes in the microbiome, that happened as a result of the success we've had fighting pathogens, have now contributed to a whole new set of diseases that we have to deal with."

The microbiome is also being linked to diseases including inflammatory bowel disease, Parkinson's, whether cancer drugs work and even depression and autism.

Obesity is another example. Family history and lifestyle choices clearly play a role, but what about your gut microbes?

This is where it might get confusing.

A diet of burgers and chocolate will affect both your risk of obesity and the type of microbes that grow in your digestive tract.

So how do you know if it is a bad mix of bacteria metabolising your food in such a way, that contributes to obesity?

Prof Knight has performed experiments on mice that were born in the most sanitised world imaginable.

Their entire existence is completely free of microbes.

He says: "We were able to show that if you take lean and obese humans and take their faeces and transplant the bacteria into mice you can make the mouse thinner or fatter depending on whose microbiome it got."

Topping up obese with lean bacteria also helped the mice lose weight.

"This is pretty amazing right, but the question now is will this be translatable to humans"

This is the big hope for the field, that microbes could be a new form of medicine. It is known as using "bugs as drugs".

Goldmine of information

I met Dr Trevor Lawley at the Wellcome Trust Sanger Institute, where he is trying to grow the whole microbiome from healthy patients and those who are ill.

"In a diseased state there could be bugs missing, for example, the concept is to reintroduce those."

Dr Lawley says there's growing evidence that repairing someone's microbiome "can actually lead to remission" in diseases such as ulcerative colitis, a type of inflammatory bowel disease.

And he added: "I think for a lot of diseases we study it's going to be defined mixtures of bugs, maybe 10 or 15 that are going into a patient."

Microbial medicine is in its early stages, but some researchers think that monitoring our microbiome will soon become a daily event that provides a brown goldmine of information about our health.

Prof Knight said: "It's incredible to think each teaspoon of your stool contains more data in the DNA of those microbes than it would take literally a tonne of DVDs to store.

"At the moment every time you're taking one of those data dumps as it were, you're just flushing that information away.

"Part of our vision is, in the not too distant future, where as soon as you flush it'll do some kind of instant read-out and tells you are you going in a good direction or a bad direction.

"That I think is going to be really transformative."

This article originally appeared on bbc.com and was written by James Gallagher

Illustrations: Katie Horwich

5 Ways Yoga Benefits Your Mental Health

Yoga teacher and licensed psychotherapist Ashley Turner says yoga is the key to psychological and emotional healing as well as resolving issues with self-confidence, relationships, and more.

Ever notice how good you feel -- mentally -- when you're practicing yoga regularly?

Yoga teacher and licensed psychotherapist Ashley Turner, who is launching a groundbreaking new Yoga Psychology 300-hour advanced yoga teacher training next month, says yoga is the key to psychological and emotional healing as well as resolving issues with self-confidence, relationships, family of origin issues, and more.

"Yoga is a psychology -- the whole practice helps us work with the nature of the mind, the nature of being a human, how emotions live in our bodies, how they affect our behavior and our minds," says Turner, who reveals that yoga helped her recognize and cope with her own low self-esteem. "This course is reclaiming the deeper roots of the practice, not just asana -- the mental and emotional benefits."

Below are 5 ways that yoga can benefit your mental health and well-being and even improve your relationships, according to Turner.

5 Ways Yoga Benefits Your Mental Health

1. It moves you from the sympathetic nervous system to the parasympathetic nervous system, or from flight-or-flight to rest-and-digest. You typically have less anxiety and enter a more relaxed state. As soon as you start breathing deeply, you slow down out of fight or flight and calm your nervous system.

2. It helps you build your sense of self. Through yoga, you get to know yourself and cultivate a more nonjudgmental relationship with yourself. You are building self-trust. You exercise more and eat healthier, because your unconscious mind tells you, "I'm worthy of this me time, this effort." At the end of the day, everything comes down to your relationship with yourself. When you get more confident and become more rooted in your sense of self and your center, you develop a healthy, balanced ego, where you have nothing to prove and nothing to hide. You become courageous, with high willpower. You're not afraid of difficult conversations -- you know you're still going to be OK at the end of the day.

3. It improves your romantic relationship. When you're more centered and more peaceful with yourself, you'll be the same way with your partner -- you'll view them through the same lens of compassionate, unconditional love. You're less reactive -- for example, you may know that snapping at your partner is not a wise choice.

4. It helps you become aware of your "shadow" qualities. The yoking of solar and lunar (light and dark) in yoga makes us recognize qualities in ourselves that we were not aware of, helping us be more mindful. A lot of my work centers on the shadow concept from Carl Jung. How do we look at those places in our bodies where we hold tension, tightness, knots of energy? That's typically where we are holding our psychological or emotional energy. We work from the outside in, so asana is so important. A backbend will open your heart and release the stiffness between the shoulder blades -- at some point, you will have some sort of emotional release, which you may or may not be conscious of. It's about doing the inner work to shift or change and be open to doing your best with your weaknesses and faults.

5. It helps you deal with family of origin issues. Essentially that's our karma -- we can’t give back our family, we're born into it and that's what you get. It's about owning what I call sacred wounds (rather than blaming) and taking them on more mindfully. You’re the only one that can change -- the only thing you can do is control your actions and your behavior. Other people will inevitably be forced to show up in a different way you’re showing up in a different way. Think of the Warrior poses -- yoga helps you rise up and do your best.

This article originally appeared on yogajournal.com and was written by JENNIFER D'ANGELO FRIEDMAN

5 Signs You Need a Break + 5 Things to Do About It

Work. Friends. Projects. Errands. Family. Health. Repeat. Life has put a lot on our plates, and it seems to be adding more. It is easy to get caught up in this plight of modern life, but you do not have to. Here are five things that I most typically notice and hear as signs of needing a break, and five ways to remedy them.

Signs It’s Time for a Break

1. You dread the alarm clock. Your alarm clock goes off, no matter the hour or day, and all you want is to stay crawled up in bed.

2. Your fuse is short. No matter what someone says, it is not the right thing. You are constantly triggered for arguably no real reason.

3. You avoid what you know you like. You start making excuses for not going to yoga - to that class you love - or a friend’s house you always enjoy, claiming stress and tiredness.

4. Your diet starts to waver. You start eating foods you know make you feel bad, and other foods you simply know are bad, saying, “just today.”

5. You simply do not care. You start to spend more time surfing the web at work, flipping through channels at home, ignoring messages and invites from friends, and pretending your family does not exist, all in the name of “rest” and silence.

Ways to Give Yourself a Break

1. Get offline. Turn the internet off two hours before bed, and turn your handheld devices off for at least eight hours a day. Let your mind rest, and spare it the endless stream of often unnecessary information. (This one is hard, I know.)

2. Take a local adventure. Take yourself  somewhere new or unfrequented in your city; think neighborhood walk, proper restaurant diner, bikini picnic in the park, or museum wandering. Simply experiencing something new - with different people, air, and vibe - will refresh your mind and body.

3. Plan an escape. Plan a day, week, or weekend holiday within the next six months; anything outside of and away from your day-to-day routine. Something to look forward to will add a skip to your daily step.

4. Laugh. There is really no better remedy. Cures you from the inside out.

5. Do something crazy. Go to a seemingly ridiculous class, plan a one-day escape to the beach, go out for a night on the town, or do something you think you never have time to do, or is simply nuts. The thrill will rejuvenate you.

This article originally appeared on mindbodygreen.com and was written by Lauren Imparato

7 Very Important Reasons To Take A Nap Right Now

Sleep is very, very good. And while it’s essential to get a solid seven to nine hours per night, when you occasionally miss the mark, a nap can help a great deal. Hey, it’s still a good idea even if you do get enough sleep.

There’s really no excuse not to nap — especially when there are so many health benefits. Curious what those perks are? Here are seven reasons why you should take a snooze right now:

1. It’ll increase your patience

Feeling frustrated? According to researchers at the University of Michigan, who published a study in the journal Personality and Individual Differences, you should probably take a nap. Participants were asked to complete a particularly frustrating task — drawing geometric designs on a computer screen. Those who took an hour-long nap before the exercise were able to draw for 90 seconds, compared to a control group who watched a nature documentary instead of napping. They gave up after about 45 seconds.

2. You’ll be more alert

Whether you’re on a long drive or trying to get through a difficult task at work, napping is a great way to increase alertness if you’re feeling foggy. A NASA study found that after napping for forty minutes pilots were more alert, and a smaller study found that after just ten minutes participants felt more alert.

3. Just thinking about napping can lower your blood pressure

While an actual nap is certainly beneficial, so is the time before you take one. One British study found that participants’ blood pressure dropped before they even fell asleep — just anticipating the nap they were about to take was enough.

4. It helps you remember more

A study conducted by researchers in Germany found that taking an hourlong nap can dramatically improve our ability to remember information. For the study, participants were asked to remember specific words and pairs. Then, half the participants watched a DVD while the other half napped. When asked about their memory of the words, the nap group performed five times as well as the DVD group.

5. It can improve creativity

If you haven’t been feeling too imaginative lately, it’s probably time to hit the hay. A study conducted by psychiatrist Sara Mednick out of the University of California, San Diego, found that people who take REM naps ― the deep sleep state where you’re dreaming ― were more creative when it came to problem solving than non-REM nappers.

6. Regular naps may help prevent heart disease

One study of 23,000 Greek adults found that people who took midday naps — a.k.a. “siestas” — were over thirty percent less likely to die of heart disease, according to The Washington Post.

“Napping may help deal with the stress of daily living,” Michael Twery of the National Heart Lung and Blood Institute said, according to the Washington Post. “Another possibility is that it is part of the normal biological rhythm of daily living. The biological clock that drives sleep and wakefulness has two cycles each day, and one of them dips usually in the early afternoon. It’s possible that not engaging in napping for some people might disrupt these processes.”

7. Taking a 10-minute rest is beneficial, too

Don’t think you can actually fall asleep? It may not matter all that much. A 2007 study, which took a look at the effects of napping versus resting, found that simply lying down for 10 minutes improved mood regardless of whether or not the person fell asleep.

What are you waiting for? Get snoozing and dream on!

This article originally appeared on huffingtonpost.com.au and was wirtten by Leigh Weingus