The study from the University of North Carolina School of Medicine reveals some gut microbes increase the absorption of dietary fats, allowing the host organism to extract more calories from the same amount of food.
"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 researcher John Rawls.
Previous studies have showed gut microbes aid in the breakdown of complex carbohydrates, but their role in dietary fat metabolism has remained a mystery
The study was carried out in zebrafish, which are optically transparent when young.
By feeding the fish fatty acids tagged with fluorescent dye, the researchers were able to directly observe the absorption and transport of fats in the presence or absence of gut microbes.
Researchers pinpointed one group of bacteria, Firmicutes, as instrumental in increasing fat absorption.
They also found the abundance of Firmicutes in the gut was influenced by diet.
"Our findings indicate that the gut microbiota can increase the host's ability to harvest calories from the diet by stimulating fat absorption," said the study's lead researcher, Ivana Semova.
"Another implication is that diet history could impact fat absorption by changing the abundance of certain microbes, such as Firmicutes, that promote fat absorption," Semova said.
"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," said Semova.
The study was published in the journal 'Cell Host and Microbe'.
