microbiology

Microbiology: Straight from the gut

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(I first heard about gut transplants when I was interviewing Michael Zasloff of Georgetown University for a different piece. The idea that you can transplant someone’s entire intestines blew my mind. None of the Nature editors had ever heard of it, either. The implications–that you can study how bacteria colonize a gut after birth–really make this story compelling. And yes, I got to see some gruesome stuff. I’ll never quite forget the startlingly yellow poop Stuart Kaufman raved about. You can download a pdf of this article.)

The human body teems with microbes. Apoorva Mandavilli meets the surgeons who have a rare opportunity to watch an ecosystem being established as they transplant guts from one person to another.

Dirty business: gut transplants give bacteria and scientists new choices.

Stephanie is the first to admit that she never had the guts for life. She was born with familial adenomatous polyposis, a genetic disorder in which thousands of polyps form in the colon. By the age of 22, much of the organ had to be removed. Four years later, a massive benign tumour choked off the blood supply to her small intestine, so doctors cut out all but a metre of it. For the next six years, she was fed by a tube every night until the feeding left her liver badly scarred and fighting recurring infections. “I was given a month to live,” she says.

That’s when doctors referred Stephanie to Georgetown University Hospital in Washington DC. There, on 17 April 2006, surgeons cut out her stomach and what was left of her small and large intestine and replaced it with new organs from a donor who had died days earlier in Tennessee. “Oesophagus to anus, her entire gastrointestinal tract was in the garbage can,” says Tom Fishbein, who directed the surgery. “She got a brand new one.”

All organ transplants are complicated, but there are only a handful of centres in the United States that have the
 expertise to transplant
 a small intestine, the seven metres of coiled tissue connected up to the stomach at one end and the large intestine at the other. The technique is complicated because the gut is teeming with trillions of bacteria and other microbes, plus the bulk of the body’s lymphocytes.

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SARS: Open season

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(I stumbled across this story when I was in Beijing in October 2005, interviewing scientists for a special package on Chinese research. I had lunch with Hongkui Deng, a rising star, who took me completely by surprise when he told me his lab had shifted focus from stem cells to SARS. When I looked into it and discovered he wasn’t alone, I knew I was on to a nice story about Chinese science, a rarity in those days. You can download a pdf of the article.)

SARS caught China unawares. But the ensuing struggle to characterize and contain the virus has put the country’s work on infectious diseases back on target.

Like anyone who was in Beijing in the spring of 2003, Hongkui Deng remembers it vividly. The Chinese government could no longer deny that the country was in the grip of a new and potentially fatal disease: severe acute respiratory syndrome (SARS). By July, the epidemic would have spread, affecting more than 8,000 people worldwide and claiming 813 lives; but in April, the panic was already palpable.

Normally bustling, the streets of Beijing were virtually deserted. The few people who ventured out wore masks and gloves, and avoided even eye contact with others. Cinemas, schools and shops were closed. It was, as many describe it, frightening and eerie — even apocalyptic. “Everyone was scared,” Deng recalls.

Deng, a cell biologist, had returned home in 2001 after more than a decade in the United States. Now based at Peking University, he was pursuing his research on embryonic stem cells. Returning from a conference in April 2003, he learnt that the mother of one of his students had SARS. Once officials had sprayed the lab, Deng’s students began asking if they could work on the disease that was paralysing the nation.

“Everybody wanted to do something,” he says. Deng had limited experience in virology, apart from a short stint working on HIV, and his students had even less. But like many other scientists in China, the team saw research on SARS as both an opportunity and a duty, and set about mastering the basics — fast.

Feverish activity

For at least six months, Deng’s lab stopped working on stem cells and focused entirely on SARS. It wasn’t alone. Across the country, scientists trained in protein science, anatomy, immunology and biochemistry — almost anybody who could contribute in any way — were shelving their normal projects. “Everyone was working on SARS,” says Deng. “You just had to.”

That commitment has paid off. Although China still faces a great many hurdles, its government and scientific community are becoming better prepared to combat epidemics, say some US scientists. Long after global interest in SARS has waned, Chinese scientists are still publishing important work on the disease.

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