September 13, 2012
New Study Shows Bacteria in Intestine Boost Fat Absorption
Connie K. Ho for redOrbit.com — Your Universe Online
A group of researchers from the University of North Carolina (UNC) and Carnegie Institution for Science recently discovered that microbes in the intestine help the body increase the absorption of calories from food by extracting dietary fats.
The results from the study on microbes in the digestive tract were recently published in the journal Cell Host & Microbe.
"This study is the first to demonstrate that microbes can promote the absorption of dietary fats in the intestine and their subsequent metabolism in the body," said senior study author John Rawls, an associate professor in the Department of Cell and Molecular Physiology at UNC. "The results underscore the complex relationship between microbes, diet and host physiology."
While past studies have looked at how gut microbes assist in taking apart complex carbohydrates, the new research examined the role of bacteria in the metabolism of dietary fat. The project utilized zebrafish and gave them fatty acids colored with fluorescent dye to determine the uptake and mobility of fats with or without microbes in the dietary track.
The researchers discovered that a type of bacteria known as Firmicutes was vital in helping with the absorption of fat. The appearance of Firmicutes in the intestines depended on the fish´s diet. Those animals that maintained normal diets had higher amounts of the bacteria than those that were not given food several days in a row.
Previous studies have already determined that there are higher levels of Firmicutes present in the intestines of obese humans.
"Our findings indicate that the gut microbiota can increase the host's ability to harvest calories from the diet by stimulating fat absorption," commented lead researcher Ivana Semova, who was also enrolled as a UNC graduate student during the study.
"Another implication is that diet history could impact fat absorption by changing the abundance of certain microbes, such as Firmicutes, that promote fat absorption."
The team of investigators concluded that, though the study was conducted with fish, their findings will likely also be applicable to humans
"The unique properties of zebrafish larvae are helping us develop a better understanding of how the intestine functions with the goal of contributing to ongoing efforts to reduce the impact of diseases associated with altered lipid metabolism, such as diabetes, obesity, and cardiovascular disease,” explained Steve Farber, a researcher with the Carnegie Institution for Science.
“Our collaboration with the Rawls lab is now focused on how specific gut bacteria are able to stimulate the absorption of dietary fat. We hope to use that information to develop new ways to reduce fat absorption in the context of human diseases."
Furthermore, the results of the study may prove helpful to researchers studying new treatments for obesity and related diseases.
"If we can understand how specific gut bacteria are able to stimulate absorption of dietary fat, we may be able to use that information to develop new ways to reduce fat absorption in the context of obesity and associated metabolic diseases, and to enhance fat absorption in the context of malnutrition," continued Rawls in the statement.