Two for One: Fecal Transplant + Obesity

Fecal transplant has quickly moved from the status of a medical oddity to an accepted, lifesaving therapy for Clostridium dificile colitis. In parallel to its development for c. diff, obesity researchers have been studying the impact of transplanting fecal microbes from animals with obesity to animals without it, and vice versa.

So the case report of a woman who experienced dramatic weight gain after receiving a fecal transplant from her daughter for c. diff is getting lots of attention. Her daughter had excess weight at the time of the transplant. After the transplant, both mother and daughter progressed from a BMI of 26 to a BMI in the range of obesity.

Neha Alang and Colleen Kelly report that their patient had a stable weight prior to the fecal transplant. According to Kelly,  the patient “came back about a year later and complained of tremendous weight gain. She felt like a switch flipped in her body, and to this day she continues to have problems.” Three years following the transplant, she had reached a BMI of 34.5.

Both the authors of this report and independent experts who wrote a companion commentary caution that definitive conclusions are not possible from this single case report. They note that many factors may have contributed.

What they do agree upon is that this case reinforces the importance of selecting an appropriate, healthy donor for fecal transplants, with a BMI < 25 being one of the criteria. It seems like many patients feel more comfortable with a related donor. But in fact, safety data demonstrates that this is a bad idea compared to using stool from a carefully selected healthy volunteer donor.

We still have a lot to learn about both both fecal transplants and the role of gut microbes in obesity.

Click here to read more from the LA Times, here to read the case report, and here to read the companion commentary.

Lion King in the Shadow of Toilet Paper, photograph © David Blackwell / flickr

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