Tuesday, November 7, 2006

Gut check time?

drj writes "Dieters complain about growing fatter despite eating less and exercising more. Backhed and colleagues now provide surprising support for half this claim. Germ-free mice “conventionalized” with microorganisms from the guts of normal mice increase their body fat 60% in just 2 weeks despite eating less. Activity levels were not reported. The bacteria were transmitted by spreading the contents of the distal intestine from normal mice onto the fur of germ-free mice. The microorganisms apparently act by increasing the uptake of sugars from the gut into the bloodstream. Adaptive immunity is not involved in this response because conventionalized Rag1-knockout animals behave similarly. The authors propose that Western diets may predispose to obesity by promoting certain gut microorganisms.
Will obesity, like ulcers caused by Helicobacter pylori, now be understood as having a key microbiological component? Is there a market for bugs from skinny people?"
PNAS "The gut microbiota as an environmental factor that regulates fat storage" Fredrik Backhed, Hao Ding, Ting Wang, Lora V. Hooper, Gou Young Koh, Andras Nagy, Clay F. Semenkovich, and Jeffrey I. Gordon. Proc Natl Acad Sci U S A. 2004 Nov 2;101(44):15718-23. PMID: 15505215

1 comment:

Reuel said...

Pre/Probiotics definitions

Prebiotics are nondigestible foods that selectively stimulate bacteria already resident in the colon, benefitting the host. Probiotics are food supplements that contain microbes, thereby changing the intestinal microbial composition and benefitting the host. Here is a review [nih.gov] of diet therapy of inflammatory bowel disease, courtesy of scientists Kirin Brewery (and no, they don't recommend a beer diet).