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Drug protects your gut bacteria from antibiotics
In this section n Mystery of ancient dog sacrifices, page 8 n AI with imagination draws remembered scenes, page 14 n Should you pay to store blood that could save your child?, page 20
Fish just can’t resist the smell of plastic
“A formulation of activated charcoal protected 90 per cent of bacteria species affected by antibiotics”
CNRI/SCIENCE PHOTO LIBRARY
HUNDREDS of marine species are known to eat plastic – including those that regularly end up on our dinner plates. But why? It now seems that ocean-borne plastic has a smell that marine animals find appealing. Matthew Savoca, now at the NOAA Southwest Fisheries Science Center in San Diego, California, exposed schools of anchovies to seawater with an odour of plastic. To make this, the team left plastic beads in the ocean for three weeks, then stirred the beads into seawater samples before filtering them out – leaving just the associated odour chemicals. In the ocean, plastic quickly becomes covered with a layer of algae that release smelly sulphur compounds. Foraging fish such as anchovies, which feed on algaemunching marine crustaceans called krill, are thought to use these compounds to help them locate prey. When analysing videos of the anchovies, the researchers noticed that the fish reacted to the plasticscented solutions as if they were their crustacean prey. The decision to use solutions with a plastic smell rather than actual pieces of plastic meant the fish weren’t responding to visual cues but simply to the odours. The fish did not respond to clean plastic (Proceedings of the Royal Society B, DOI: 10.1098/ rspb.2017.1000). This could be an issue for animals higher up the food chain, like us. “There’s no doubt that we eat microplastics when we eat seafood,” says Chelsea Rochman at the University of Toronto. What we don’t know, she says, is how much of the chemicals leaching out of the plastic then enter our systems – and whether it matters if they do. A report by the UN Food and Agriculture Organization released last week highlights how little we know about plastic consumption by animals and the possible impact on human health. Josh Gabbatiss n
volunteers. A five-day course of the common antibiotic moxifloxacin was given to 28 people, half of whom also took DAV132 twice a day throughout the treatment, and for two extra days at the end. A further eight volunteers took DAV132 on its own, while eight people took nothing at all. De Gunzberg’s team found that DAV132 didn’t affect how much
of the antibiotic made it into a person’s bloodstream, suggesting that it wouldn’t stop the drug from treating a bad infection. However, the faeces of those who took DAV132 with moxifloxacin had only around 1 per cent of the level of antibiotic found in the faeces of those who took the antibiotic on its own. This indicates that the charcoal –Home to your microbiome– mopped up moxifloxacin in the large intestine (bioRxiv, doi. org/cbsj). Around 250 species of bacteria fell in number in the guts of those who took the antibiotic alone. “Close to 90 per cent of those biotech company based in Paris, species were protected by our think they have found a solution. product,” says de Gunzberg. At Activated charcoal – a superthis stage, the team didn’t look absorbent material – is routinely at whether this reduced the used to soak up drugs in the guts incidence of side effects from of people who have overdosed, antibiotics, such as diarrhoea. and the team have evidence that “The results are promising,” a modified version could do this says Willem van Schaik at the for antibiotics. University of Birmingham, UK. To stop charcoal from simply “It’s a really exciting approach soaking up an entire dose of oral to protect the microbiome from antibiotics, the team covered tiny antibiotics.” pieces of activated charcoal with a The team want to see if the special coating. This breaks down product can stop resistant by the time the charcoal reaches bacteria from developing. The the large intestine, allowing it to plan is to start testing the charcoal mop up any antibiotics that make in people taking antibiotics to it this far and protect the rich treat infections next year. ecosystem of beneficial bacteria In the meantime, people that live there. shouldn’t give themselves regular The team tested its slow-release activated charcoal, as this could activated charcoal, named DAV132, simply stop their antibiotics in a clinical trial of 44 healthy from working. Jessica Hamzelou n
Drug protects your gut bacteria from antibiotics ANTIBIOTICS can save your life, but they can also mess up your microbiome. A formulation of activated charcoal could help, protecting your body from the downsides of antibiotics. Stomach pains and diarrhoea are familiar side effects for many people who take antibiotics. But by messing with the balance of microorganisms in the body, antibiotics may also cause longerterm changes, potentially leading to obesity and allergies. And by killing too many of the good bacteria in your gut, they can make way for harmful and even drug-resistant bacteria, such as C. difficile, which is responsible for around 30,000 deaths a year in the US. Jean de Gunzberg and his colleagues at Da Volterra, a
19 August 2017 | NewScientist | 7
Fish just can’t resist the smell of plastic
“A formulation of activated charcoal protected 90 per cent of bacteria species affected by antibiotics”
CNRI/SCIENCE PHOTO LIBRARY
HUNDREDS of marine species are known to eat plastic – including those that regularly end up on our dinner plates. But why? It now seems that ocean-borne plastic has a smell that marine animals find appealing. Matthew Savoca, now at the NOAA Southwest Fisheries Science Center in San Diego, California, exposed schools of anchovies to seawater with an odour of plastic. To make this, the team left plastic beads in the ocean for three weeks, then stirred the beads into seawater samples before filtering them out – leaving just the associated odour chemicals. In the ocean, plastic quickly becomes covered with a layer of algae that release smelly sulphur compounds. Foraging fish such as anchovies, which feed on algaemunching marine crustaceans called krill, are thought to use these compounds to help them locate prey. When analysing videos of the anchovies, the researchers noticed that the fish reacted to the plasticscented solutions as if they were their crustacean prey. The decision to use solutions with a plastic smell rather than actual pieces of plastic meant the fish weren’t responding to visual cues but simply to the odours. The fish did not respond to clean plastic (Proceedings of the Royal Society B, DOI: 10.1098/ rspb.2017.1000). This could be an issue for animals higher up the food chain, like us. “There’s no doubt that we eat microplastics when we eat seafood,” says Chelsea Rochman at the University of Toronto. What we don’t know, she says, is how much of the chemicals leaching out of the plastic then enter our systems – and whether it matters if they do. A report by the UN Food and Agriculture Organization released last week highlights how little we know about plastic consumption by animals and the possible impact on human health. Josh Gabbatiss n
volunteers. A five-day course of the common antibiotic moxifloxacin was given to 28 people, half of whom also took DAV132 twice a day throughout the treatment, and for two extra days at the end. A further eight volunteers took DAV132 on its own, while eight people took nothing at all. De Gunzberg’s team found that DAV132 didn’t affect how much
of the antibiotic made it into a person’s bloodstream, suggesting that it wouldn’t stop the drug from treating a bad infection. However, the faeces of those who took DAV132 with moxifloxacin had only around 1 per cent of the level of antibiotic found in the faeces of those who took the antibiotic on its own. This indicates that the charcoal –Home to your microbiome– mopped up moxifloxacin in the large intestine (bioRxiv, doi. org/cbsj). Around 250 species of bacteria fell in number in the guts of those who took the antibiotic alone. “Close to 90 per cent of those biotech company based in Paris, species were protected by our think they have found a solution. product,” says de Gunzberg. At Activated charcoal – a superthis stage, the team didn’t look absorbent material – is routinely at whether this reduced the used to soak up drugs in the guts incidence of side effects from of people who have overdosed, antibiotics, such as diarrhoea. and the team have evidence that “The results are promising,” a modified version could do this says Willem van Schaik at the for antibiotics. University of Birmingham, UK. To stop charcoal from simply “It’s a really exciting approach soaking up an entire dose of oral to protect the microbiome from antibiotics, the team covered tiny antibiotics.” pieces of activated charcoal with a The team want to see if the special coating. This breaks down product can stop resistant by the time the charcoal reaches bacteria from developing. The the large intestine, allowing it to plan is to start testing the charcoal mop up any antibiotics that make in people taking antibiotics to it this far and protect the rich treat infections next year. ecosystem of beneficial bacteria In the meantime, people that live there. shouldn’t give themselves regular The team tested its slow-release activated charcoal, as this could activated charcoal, named DAV132, simply stop their antibiotics in a clinical trial of 44 healthy from working. Jessica Hamzelou n
Drug protects your gut bacteria from antibiotics ANTIBIOTICS can save your life, but they can also mess up your microbiome. A formulation of activated charcoal could help, protecting your body from the downsides of antibiotics. Stomach pains and diarrhoea are familiar side effects for many people who take antibiotics. But by messing with the balance of microorganisms in the body, antibiotics may also cause longerterm changes, potentially leading to obesity and allergies. And by killing too many of the good bacteria in your gut, they can make way for harmful and even drug-resistant bacteria, such as C. difficile, which is responsible for around 30,000 deaths a year in the US. Jean de Gunzberg and his colleagues at Da Volterra, a
19 August 2017 | NewScientist | 7