Monday, February 4, 2013

Fabulous Synthetic Poop!

Last year I wrote about important scientific breakthroughs being made in understanding our microbiomes, the collection of trillions of bacteria that live on and in our bodies  -- see How About A Fecal Transplant?

One conclusion from this research is that our general cultural attitude that "the only good microbe is a dead microbe" is emphatically wrong.  We are very dependent for our health and well-being on these little critters, and in fact we can't exist without them.

The bacteria that colonize our guts are particularly noteworthy -- they enable us to digest food, synthesize certain vitamins, and fight off many infectious diseases. Normally the thousands of bacterial strains in our intestines form a complex ecological community in which competition among them is in balance. Of course, certain intestinal bacteria are quite harmful to us if they overwhelm the good guys, which can happen because of changes in diet, physical trauma, encounters with environmental toxins, or illness that weakens the immune system. One example is Clostridium Difficile, a strain of bacteria which can cause chronic severe diarrhea and other intestinal problems and is linked to 14,000 deaths each year in the United States. It is notoriously hard to treat.

In the past we have responded to Clostridium Difficile and other intestinal infections with a "nuke'm all" strategy of giving patients broad-spectrum antibiotics that kill both bad and good bacteria, not unlike a gardener spraying the entire garden with herbicide to get rid of weeds.  This has two unfortunate consequences.  First, the harmful bacteria become resistant to the antibiotics, requiring ever more powerful forms of treatments.  Second, wiping out the good bacteria destroys the normal ecological balance in the microbiome that can help keep the bad bacteria in check.

One very promising approach to these problems has been the fecal transplant, an "interesting" procedure in which the stool from a healthy donor is implanted in the intestinal tract of a patient with a bacterial infection, for example through fecal suppositories. The idea is that the healthy stool contains the complex collection of microbes needed to restart a depleted microbiome in another person. Despite what researcher Dr. Alexander Khoruts calls the "ick" factor, the procedure seems to work, particularly in Clostridium Difficile infections.

And now the really good news for those of us who have trouble with the concept of fecal suppositories, or in general with the idea that somebody else's poop can be good for us. A group of British and Canadian researchers reported just this month in the journal Microbiome that they have developed a successful new procedure that removes much of the "ickiness."  Their report has a catchy title:
"Stool substitute transplant therapy for the eradication of Clostridium difficile infection: ‘RePOOPulating’ the gut."
Who says scientists don't have a sense of humor?

The procedure is to take poop from a healthy donor, but instead of transplanting it directly to a recipient (thence the "ickiness), the bacteria in the poop are cultured in a laboratory and about 30 of the purified beneficial strains are combined to make "synthetic poop" that contains the bacteria but not the "ick."  The researchers call this material "RePOOPulate." Seriously.

The RePoopulate procedure has the advantage of allowing a high degree of control over the kinds and numbers of bacteria in the transplant.  This means the exact same treatment can be re-administered if necessary, and it also reduces the chances of inadvertently transferring diseases from the donor.  And once the bacteria have been cultured new RePoopulate can be concocted without a new poop donor.

This seems like a great advance to me, and you really have to give the researchers credit.  There is, however, just one teensy problem left to work on.  The transplant is performed during a colonoscopy.  For those unfamiliar with this procedure, see Dave Barry's famous essay on the subject.

Of course, I suspect if you are someone suffering from a Clostridium difficile infection you wouldn't think twice if a colonoscopy would end your suffering.

As for myself, I'm still hoping for a synthetic poop pill.
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Additional links for the scatologically inclined:

"How About A Fecal Transplant?"  My blog last year on this general topic.
"Stool substitute transplant therapy...."  The Microbiome journal article on synthetic poop.
"Artificial Poop Transplant May Fight Bacterial Infection:"  A somewhat more readable article in LiveScience about the procedure.
 "Microbes For Breakfast"  My previous blog on why eating microbes is good for you.