DR. MICHAEL MOSLEY: Take care of the viruses in your gut and you could live to be 100!

What are the secrets to a long and healthy life? Most people realize that staying healthy as you age requires regular exercise, maintaining an appropriate weight, getting enough sleep, and managing stress.
But now you can add something much more surprising to this list: get infected by the right viruses.
At least that’s the conclusion of a recent study of centenarians from Japan and Sardinia.
The Japanese are notoriously long-lived, while the small Italian island of Sardinia claims to have one of the highest proportions of people living to 100 years or older.
It was always thought that this was mainly related to diet and lifestyle, but it now appears that getting the right viruses in your gut can also make a difference.

It was always thought that this was mainly related to diet and lifestyle, but it now appears that getting the right viruses in your gut can also make a difference
In a study published earlier this month in the journal Nature Microbiology, researchers from the Massachusetts Institute of Technology and Harvard University in the US examined fecal samples from nearly 200 centenarians from those two areas.
The scientists used it to analyze the participants’ gut microbiomes — the community of trillions of microbes that live in our gut and have profound effects on our health — looking for clues about their longevity.
They found that centenarians had both a greater range of “good” bacteria and more “good” viruses compared to people in their 60s.
It might surprise you to know that in addition to the bacteria we’ve all been reading so much about lately, our gut is also home to many viruses and fungi.
We usually think of viruses as harmful to us – and they do in fact cause a number of nasty diseases – but most of them aren’t bad and some even seem to be beneficial.
Viruses are tiny, about 100 times smaller than bacteria, and difficult to study in part because of their size, which is why the viruses that live in our gut have received much less attention than the larger, more prominent bacteria.
You may be wondering what the viruses do in the guts of centenarians that help them stay healthy?
At least some of the viruses attack and kill “bad” bacteria, the kind that can cause inflammation and serious infections in the gut.
These particular viruses, called bacteriophages, are very common and are increasingly used in medicine as an alternative to antibiotics, particularly in the treatment of drug-resistant skin and gut infections.
Because unlike antibiotics, bacteria do not seem to develop resistance to bacteriophages.
The researchers believe that some of the viruses in the centenarians’ guts not only kill harmful microbes, but are also good at producing the gas hydrogen sulfide.
At first glance, that doesn’t sound like a good thing, since hydrogen sulfide smells like rotten eggs and is one of the reasons why some people produce such noxious fumes when there is no wind.
But surprisingly, while hydrogen sulfide smells awful outdoors, it has many potential benefits when it’s created in the gut. One of the most important is that it helps maintain the gut lining, a barrier of tightly packed cells that allows your body to absorb nutrients but also keeps bacteria and toxins from entering your blood.
And when the bad comes out, it can lead to chronic inflammation, which in turn is a leading cause of diseases of old age like arthritis, heart disease, dementia and cancer.
Hydrogen sulfide also has its own direct, powerful anti-inflammatory and antioxidant effects, which may explain why studies have shown it plays an important role in maintaining the health of our brain, heart, liver, and other organs.
In small doses, hydrogen sulfide has also been shown to improve the efficiency of the mitochondria, the “batteries” in our cells, which in turn suggests that it contributes to improved energy and cellular health.
It’s believed that stool samples from centenarians could one day be used to culture the beneficial viruses – which would then be given to people who don’t age well, either as a pill or as a stool transplant.
If you don’t feel like it, then it’s best to do things that have already been shown to benefit your overall health and that of your microbiome.
That means eating plenty of fruits, vegetables, and fiber-rich legumes, including plenty of sulfur-rich vegetables like broccoli, cauliflower, cabbage, kale, and radishes, which help boost internal production of hydrogen sulfide.
Another great way to cultivate your good gut microbes is through gardening, as it puts you in closer contact with insect-rich soil. This, along with exercise and time outdoors, could be one reason gardeners tend to live longer. Spending more time with loved ones is another proven good way to help you reach old age.
A 2019 study of 117 people published in Nature found that those who were happily married or had many close friends had a richer and more diverse microbiome than those who lived alone or were socially isolated.
So it seems that staying in close contact with friends is also a great way to keep your microbial friends, whether bacteria or viruses, happy.
I hate traffic noise so much that many years ago I convinced my wife Clare that we should move to a quiet, leafy street.
Even now, I take earplugs and noise-cancelling headphones with me when I travel.
Clare thinks I’m overly sensitive, so I was pleased to show her the results of a recent Swedish study that found that playing traffic noise at a volume of just 40dB (similar to talking softly in a library) had a Role played has a significant impact on their ability to concentrate and get work done.
Why faking a smile is good for your marriage
Social isolation and mask-wearing during the pandemic mean some of us may have slipped from the habit of smiling.
At least that seems to be the case in Japan, where there’s been a recent boom in courses teaching people how to do it.
While I don’t want to spend the time or money on it, there’s a surprising amount of evidence that a smile can be beneficial.
In a 2001 University of California study, researchers analyzed pictures of women taken in their 20s and found that decades later, those who were thought to have smiled most naturally were happier, and far more likely to do so married and remained happily married than those who did ‘T.
This may be because “smiling people attract other happier people and the combination can lead to a greater likelihood of lasting marriage,” the researchers said.

Social isolation and mask-wearing during the pandemic mean some of us may have slipped from the habit of smiling
However, if you don’t feel like smiling, faking it in a certain way can be beneficial. New research in Human Behavior magazine, involving more than 3,800 people, found that imitating actors’ smiling faces in photos made people happier — as did using facial muscles to turn up the corners of their mouths.
But the “pen-in-mouth” technique — which involves placing a pen between your teeth to coax facial muscles into the shape of a simulated smile — didn’t make much of a difference.
So why would faking a smile make you feel happier? One theory has it that it stimulates the amygdala — your brain’s emotional center — to release chemicals that make us happier.
Whatever the explanation, there seems to be some truth to the old adage “smile and the world smiles with you, cry and you cry alone”.