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Interview: Mary Roach

As humans have got ourselves to the remotest parts of the globe, to the deepest nooks of the ocean and far out in space but we have yet to truly understand or discover the mysteries within ourselves - our own bodies.Nurses deal with the body every day, but author Mary Roach approaches it with a sense of wonder - like an astronaut on a first mission to space she explores it's far-flung and frightening reaches.

Her sixth and latest work is Gulp: Adventures on the Alimentary Canal. This is a mouth to rectum journey of discovery about our digestive system. And as Roach says “A lot of strange and amazing happen between the nose and tail.”

To say her books are well researched would be an understatement; with the reading list taking up to 15 pages alone so it's no wonder it takes her about two years to amass all this information into an amusing tale about the body's inner workings.

Roach says she starts her work on a book “with a few months of random flailing - reaching out, poking around on the web, making calls, turning over rocks. Figuring out what and who is out there to be covered, visited, explored”. 

“I don't write the chapters in the order they'll appear. I write up whichever one I'm done researching, and figure out the order a bit later,” she adds. 

The first chapter, Nose Job, is where the story starts with Sue Langstaff, a Harley riding sensory analyst, who uses her nose to incredible effect to forensically examine wine, beer and, more unusually, olive oil for producers. She's able to tell them what tastes good and what's gone wrong and why.

Roach's quest for knowledge has led her down some interesting avenues but she says her trip to a prison was the strangest. “I interviewed and an inmate - serving life for murder, I learned after I arrived - about his rectal holding capacity, about the defecation reflex and how to override it, and what happens when you do that too long.

“Inmates do a lot of smuggling of things, sometimes surprisingly large things, with their rectum. This was for, natch, the rectum chapter,” she says from her home in Oakland, California.

As well as interviewing others, Roach has also put herself forward to take part in understanding the body - resulting in what she says is her most embarrassing adventure to date.

For her book Bonk: The Curious Coupling of Science and Sex, she “dragged [her] husband into a research project that required [them] to have sex while being filmed in 3D ultrasound” - a dedicated author. 

Roach, who has no formal medical training and no interest in doing any due to “a short attention span” and a love of writing, is fascinated by the body and the discoveries she makes while writing her books. For this one it was the fact that “we have two sets of nostrils: external and internal” that amazed her and no doubt her readers.

“You go through life thinking you know yourself, and it turns out you've got four nostrils. Who knew? The internals ones we use for smelling on the exhale, not the inhale. When there's food in your mouth, and you exhale through your nose, you experience a lot more of the flavour/aroma of it,” she says.

Gulp ends with a cure for intractable bacterial problems in the gut which cause misery to lives of patients who are not able to travel far from a toilet; the faecal transplant.

As Roach explains, it was first performed in 1958, by a surgeon named Ben Eiseman in the early days antibiotic use which resulted in a “massive kill off or normal bacteria.”

“Eiseman thought it might be helpful to restock the gut with someone elses' normals” she writes.

However, despite is early discovery, it was only in March 2014 that the treatment was recognised by the National Institute of Health and Care Excellence (NICE). Roach attributes this to the 'ick' factor.

“People tend to want to think of themselves as minds, not bodies. We like to think we're different from animals, perhaps. Or perhaps being flesh and bone reminds us of our mortality. Whatever the reason, we turn away from the amazing, complex, miraculous machine that is… us. 

“My hope with Gulp is to replace a little of that revulsion and squeamishness with awe and curiosity. I try to cherry-pick the things people will find fascinating and surprising, hook them with that stuff, and along the way impart a little respect,” says Roach, 55. NICE's interventional procedures guidance [IPG485] supports the use of faecal for the treatment of recurrent C.diff in patients who have not responded to antibiotics. It also calls for more research "specifically to investigate optimal dosage, mode of administration and choice of donor".

Although C.diff is a bacterium that lives harmlessly in the gut of about 5% of healthy people. The use antibiotics can alter the balance of the gut, resulting in an overgrowth of C.diff. Mild symptoms include purulent watery diarrhoea, abdominal cramps, nausea and dehydration. In more severe cases the infection can cause bloody diarrhoea, fever and in a few it can even lead to colitis, sepsis, toxic megacolon, colonic rupture, and death. 

And as one of the doctors Roach interviews points out patients who are enduring such terrible symptoms are already "way beyond the ick" factor.

She ends her journey through the alimentary canal with a prediction that one day all kinds of bacterial transplants, faecal and otherwise, will be going on to fix each others inner workings.

So perhaps, in future, subject to the 'ick' factor we won't need to journey to the depths of the rainforest to find new cures but merely take a trip to the toilet.