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Swap bacteria to fix body odour
NEWS & TECHNOLOGY
Jessica Hamzelou
GOT BO? Blame the bacteria living in your armpits. Some people’s bacteria cause body odour that no deodorant can disguise. But replacing them with bacteria from a less smelly person can solve the problem. Our bodies are crawling with bacteria, and the microbes that live on our skin vary by region. Armpit bacteria probably have a role in making the compounds that make sweat smell, says Chris Callewaert at the University of California, San Diego. A few years ago, Callewaert met a pair of identical twins – one of whom had particularly bad body odour. Callewaert suspected that different mixes of armpit bacteria might be responsible for their different personal scents, so he tried swapping out the stinky twin’s armpit bacteria with his twin brother’s. The twin that didn’t smell refrained from washing for four days, to allow bacteria deep in his armpits to rise to the surface with dead skin. Meanwhile, the stinky
AI learns to crack quantum mechanics THE same type of artificial intelligence that mastered the ancient game of Go could help wrestle with the amazing complexity of quantum systems containing billions of atoms. Google’s AlphaGo artificial neural network made headlines last year when it bested a world champion at Go. After marvelling at this feat, Giuseppe Carleo of ETH Zurich in Switzerland thought it might be possible to build a similar tool to crack 12 | NewScientist | 18 February 2017
twin scrubbed his pits with antibacterial soap every day, for four days, to remove as much of his armpit bacteria as possible. Callewaert transferred bacteria from the sweet-smelling twin to his brother using swabs, and found that the man’s body odour problem rapidly disappeared. “The effects have persisted for over a year now,” says Callewaert. His team has since repeated this procedure with 17 other pairs. In each case, one person in the pair had a body odour problem, and the other person was a close relative. Before and after the bacterial transplants, the offensiveness of the previously smelly people was judged by a “trained odour panel” of eight people, says Callewaert. Out of the 18 pairs, 16 saw improvements in body odour within a month. Half of the group had long-term improvements that lasted three months or more. Callewaert presented the results at the Karolinska Dermatology Symposium in Stockholm, Sweden, last month. “It’s very cool, and the idea is
one of the knottiest problems in quantum physics: understanding many-body quantum systems. With Go, the number of possible positions on the board could exceed the number of atoms in the universe. So an approach based on brute-force calculation, while effective for a game like chess, just doesn’t work for Go. In that sense, Go resembles a classic quantum physics puzzle: how to describe a quantum system made up of billions of interacting atoms. But the weird rules of quantum mechanics mean we can’t know a quantum particle’s precise location at every point in time, meaning there are trillions of trillions of possible
IMAGE SOURCE/REX/SHUTTERSTOCK
Swap bacteria to fix body odour
–Different bacteria needed–
sound,” says Emma Allen-Vercoe at the University of Guelph in Ontario, Canada. She hopes that a similar approach might be useful for treating some skin conditions, like eczema and psoriasis. Callewaert and his colleagues are now formulating a more general brew of bacteria that could be used in place of a relative’s armpit scratchings.
“It’s still very experimental, but I’m sure it can work,” he says. In the meantime, you might be able to improve your body odour bacteria by shaving, maintaining a healthy weight and avoiding polyester clothing and fatty foods. “People that eat fast food and meat smell worse, while those that eat vegetables smell better,” says Callewaert. ■
configurations for a quantum system containing relatively few particles. That’s where artificial neural networks can help. Give such a network the rules of Go and it will figure out the optimal strategy to win the game. So perhaps it could do the same for quantum systems. To assess this idea, Carleo and Matthias Troyer, now at Microsoft, built a simple neural network designed to reconstruct the wave function of a multi-body quantum
system, or the set of probabilities describing how all the possible configurations could be arranged. They tested it on a few sample problems with known solutions and found it outperformed other tools (Science, DOI: 10.1126/science. aag2302). That’s sufficient proof of principle, Carleo says. “It’s like having a machine learning how to crack quantum mechanics, all by itself,” he says. “We have a machine dreaming of Schrödinger’s cat.” “It’s incredibly cool,” says Scott Aaronson at the University of Texas in Austin. “I expect to see a lot more of this in the future.” Jennifer Ouellette ■
“It’s like having a machine learning to crack quantum mechanics… and dreaming of Schrödinger’s cat”
Jessica Hamzelou
GOT BO? Blame the bacteria living in your armpits. Some people’s bacteria cause body odour that no deodorant can disguise. But replacing them with bacteria from a less smelly person can solve the problem. Our bodies are crawling with bacteria, and the microbes that live on our skin vary by region. Armpit bacteria probably have a role in making the compounds that make sweat smell, says Chris Callewaert at the University of California, San Diego. A few years ago, Callewaert met a pair of identical twins – one of whom had particularly bad body odour. Callewaert suspected that different mixes of armpit bacteria might be responsible for their different personal scents, so he tried swapping out the stinky twin’s armpit bacteria with his twin brother’s. The twin that didn’t smell refrained from washing for four days, to allow bacteria deep in his armpits to rise to the surface with dead skin. Meanwhile, the stinky
AI learns to crack quantum mechanics THE same type of artificial intelligence that mastered the ancient game of Go could help wrestle with the amazing complexity of quantum systems containing billions of atoms. Google’s AlphaGo artificial neural network made headlines last year when it bested a world champion at Go. After marvelling at this feat, Giuseppe Carleo of ETH Zurich in Switzerland thought it might be possible to build a similar tool to crack 12 | NewScientist | 18 February 2017
twin scrubbed his pits with antibacterial soap every day, for four days, to remove as much of his armpit bacteria as possible. Callewaert transferred bacteria from the sweet-smelling twin to his brother using swabs, and found that the man’s body odour problem rapidly disappeared. “The effects have persisted for over a year now,” says Callewaert. His team has since repeated this procedure with 17 other pairs. In each case, one person in the pair had a body odour problem, and the other person was a close relative. Before and after the bacterial transplants, the offensiveness of the previously smelly people was judged by a “trained odour panel” of eight people, says Callewaert. Out of the 18 pairs, 16 saw improvements in body odour within a month. Half of the group had long-term improvements that lasted three months or more. Callewaert presented the results at the Karolinska Dermatology Symposium in Stockholm, Sweden, last month. “It’s very cool, and the idea is
one of the knottiest problems in quantum physics: understanding many-body quantum systems. With Go, the number of possible positions on the board could exceed the number of atoms in the universe. So an approach based on brute-force calculation, while effective for a game like chess, just doesn’t work for Go. In that sense, Go resembles a classic quantum physics puzzle: how to describe a quantum system made up of billions of interacting atoms. But the weird rules of quantum mechanics mean we can’t know a quantum particle’s precise location at every point in time, meaning there are trillions of trillions of possible
IMAGE SOURCE/REX/SHUTTERSTOCK
Swap bacteria to fix body odour
–Different bacteria needed–
sound,” says Emma Allen-Vercoe at the University of Guelph in Ontario, Canada. She hopes that a similar approach might be useful for treating some skin conditions, like eczema and psoriasis. Callewaert and his colleagues are now formulating a more general brew of bacteria that could be used in place of a relative’s armpit scratchings.
“It’s still very experimental, but I’m sure it can work,” he says. In the meantime, you might be able to improve your body odour bacteria by shaving, maintaining a healthy weight and avoiding polyester clothing and fatty foods. “People that eat fast food and meat smell worse, while those that eat vegetables smell better,” says Callewaert. ■
configurations for a quantum system containing relatively few particles. That’s where artificial neural networks can help. Give such a network the rules of Go and it will figure out the optimal strategy to win the game. So perhaps it could do the same for quantum systems. To assess this idea, Carleo and Matthias Troyer, now at Microsoft, built a simple neural network designed to reconstruct the wave function of a multi-body quantum
system, or the set of probabilities describing how all the possible configurations could be arranged. They tested it on a few sample problems with known solutions and found it outperformed other tools (Science, DOI: 10.1126/science. aag2302). That’s sufficient proof of principle, Carleo says. “It’s like having a machine learning how to crack quantum mechanics, all by itself,” he says. “We have a machine dreaming of Schrödinger’s cat.” “It’s incredibly cool,” says Scott Aaronson at the University of Texas in Austin. “I expect to see a lot more of this in the future.” Jennifer Ouellette ■
“It’s like having a machine learning to crack quantum mechanics… and dreaming of Schrödinger’s cat”