Bacteria in Gut Linked to Obesity
Certain Bacteria May Pile on the Calories in Obese People
Dec. 21, 2006 -- Obese people may be getting more calories than they bargain
for from their food because of natural bacteria in their gut.
A new study shows that a certain type of gut bacterium is more common in
obese people than in leaner people.
That particular type of bacterium is good at releasing calories from food.
An abundance of those bacteria may mean that obese people are getting more
calories out of their food than lean people, possibly adding on pounds.
The findings may one day lead to a new obesitytreatment, write
Jeffrey Gordon, MD, and colleagues in Nature.
Gordon works at Washington University School of Medicine in St. Louis as a
professor and director of the Center for Genome Sciences.
It's normal to have bacteria in your gut; they help break down food.
There are many types of gut bacteria. Gordon's study suggests that the
bacterial mix differs in obese and lean people.
Gordon's team studied two types of gut bacteria in 12 obese people.
They found that one type of gut bacterium was more common in lean people
than in obese people; the other type more common in obese people than in lean
The obese participants went on a yearlong diet. As they lost weight, their
gut bacteria levels started to look more like the gut bacteria levels of lean
Gut Bacteria Test
Gordon and colleagues investigated further. They transplanted the gut
bacteria from either obese mice or lean mice into mice of normal weight.
Mice that received gut bacteria from obese mice gained more body fat over
two weeks than those that got bacteria from lean mice, even though their diets
were the same and they ate the same amount of chow.
The gut bacteria in the obese mice are more effective at releasing calories
from food, the study shows.
If that's found to also be true in people, it could offer a new avenue for
treating for excess weight.
The gut bacteria theory is a "potentially revolutionary idea,"
states a journal editorial. The editorialists note that many research questions
need to be answered before anyone starts trying to tinker with gut bacteria to
Meanwhile, a healthy diet and sensible exercise program are the
tried-and-true ways to shed extra pounds. Check with your doctor before
launching a weight