Friday, September 27, 2013

A Glance Into the Future: Fecal Transplants for Weight Loss

Associate Editor Dr. William V. Raszka offers insight into topics in the news. This week, he reflects on fecal transplants reported to assist with weight loss: 

Each day I am bombarded with information about how to lose weight. There seems to be an almost endless array of diet or exercise recommendations and oodles of gadgets “guaranteed” to work. In the past few months, one of my relatives has tried to lose weight following the South Beach diet, then a Paleolithic diet, and most recently using a smart phone application. Maybe she should try a fecal transplant.

As reported in The New York Times (Health: March 28, 2013), the bacterial flora in our guts may be at least partially responsible for weight loss or gain. Researchers have never quite understood all the reasons why people lose weight following gastric bypass surgery. However, in a recent study conducted in mice, researchers concluded that approximately 20% of the weight loss is most likely due to a change in bacterial flora.

Fattened mice that underwent gastric bypass surgery lost weight and had altered intestinal flora. Mice that underwent a sham surgery where the intestine was simply severed and re-anastomosed did not lose weight and the microbiota did not change.

Next, intestinal contents from each group were transplanted into mice lacking intestinal flora. The mice that received material from the bypass surgery group lost weight while the mice receiving material from the sham group did not.

In a study conducted in adults with potential gastrointestinal disorders, researchers found that indirect evidence of the presence of Methanobrevibacter smithii in the gut was directly related to body mass. The individuals with the highest levels of methane and hydrogen on breath tests were more likely to have more body fat. One possible explanation for this finding is that M. smithii may contribute to the breakdown of foodstuffs, making more calories available.

The general dieter may not be ready for a fecal transplant to help increase weight loss, but the more we learn about our gut and the bacteria that inhabit it, the more we realize how intertwined we are.

*This filler excerpt can be found in the July 2013 Pediatrics print journal p. 71, or online here.