Gut bacteria increase fat absorption

September 12, 2012
This confocal microscopy of intestinal epithelial cells (red) in zebrafish shows that the presence of microbes stimulates dietary fatty acid uptake and accumulation in epithelial lipid droplets (green). Credit: Ivana Semova, Ph.D.

You may think you have dinner all to yourself, but you're actually sharing it with a vast community of microbes waiting within your digestive tract. A new study from a team including Carnegie's Steve Farber and Juliana Carten reveals that some gut microbes increase the absorption of dietary fats, allowing the host organism to extract more calories from the same amount of food.

Previous studies showed aid in the breakdown of complex carbohydrates, but their role in dietary fat metabolism remained a mystery, until now. The research is published September 13 by Cell Host & Microbe.

"This study is the first to demonstrate that microbes can promote the of in the intestine and their subsequent metabolism in the body," said senior study author John Rawls of the University of North Carolina. "The results underscore the complex relationship between microbes, diet and host physiology."

The study was carried out in zebrafish, which are optically transparent when young. By feeding the fish fatty acids tagged with fluorescent dyes, an approach originally developed in Farber's lab, the researchers were able to directly observe the absorption and transport of fats in live animals. The Rawl's lab pioneered methods to grow zebrafish larvae in the presence or absence of gut microbes.

By combining approaches, they determined that one type of bacteria, called Firmicutes, is instrumental in increasing fat absorption. They also found that the abundance of Firmicutes in the gut was influenced by diet. Fish fed normally had more Firmicutes than fish that were denied food for several days. Other studies have linked a higher relative abundance of Firmicutes in the gut with obesity in humans.

The findings indicate that bacteria in the gut can increase the host's ability to absorb fat and thereby harvest more from the diet. Another implication is that a high-fat diet promotes the growth of these fat-loving Firmicutes, resulting in more fat absorption.

Although the study involved only fish, not humans, it offers insights that could help inform new approaches to treating obesity and other disorders.

"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 , such as diabetes, obesity, and cardiovascular disease. Our collaboration with the Rawls lab is now focused on how specific gut bacteria are able to stimulate absorption of dietary fat. We hope to use that information to develop new ways to reduce fat absorption in the context of human diseases," Farber said.

The research team also included lead author Ivana Semova and co-author Lantz Mackey, both of UNC, as well as co-authors Jesse Stombaugh and Rob Knight of the University of Colorado at Boulder.

Explore further: Why do the different people's bodies react differently to a high-fat diet?

Related Stories

Why do the different people's bodies react differently to a high-fat diet?

April 26, 2012
Gut flora, otherwise knows as gut microbiota, are the bacteria that live in our digestive tract. There are roughly one thousand different species of bacteria, that are nourished partly by what we eat. Each person has their ...

Studying fish to learn about fat

June 28, 2012
In mammals, most lipids (such as fatty acids and cholesterol) are absorbed into the body via the small intestine. The complexity of the cells and fluids that inhabit this organ make it very difficult to study in a laboratory ...

Zebrafish research shows how dietary fat regulates cholesterol absorption

June 22, 2012
Buttery shrimp. Fried eggs. Burgers and fries. New research suggests there may be a biological reason why fatty and cholesterol-rich foods are so appealing together.

Gastric bypass surgery alters gut microbiota profile along the intestine

July 10, 2012
Research to be presented at the Annual Meeting of the Society for the Study of Ingestive Behavior (SSIB), the foremost society for research into all aspects of eating and drinking behavior, finds that gastric bypass surgery ...

Manipulating the microbiome could help manage weight

August 26, 2012
Vaccines and antibiotics may someday join caloric restriction or bariatric surgery as a way to regulate weight gain, according to a new study focused on the interactions between diet, the bacteria that live in the bowel, ...

Recommended for you

Pair of discoveries illuminate new paths to flu and anthrax treatments

October 17, 2017
Two recent studies led by biologists at the University of California San Diego have set the research groundwork for new avenues to treat influenza and anthrax poisoning.

New method to measure how drugs interact

October 17, 2017
Cancer, HIV and tuberculosis are among the many serious diseases that are frequently treated with combinations of three or more drugs, over months or even years. Developing the most effective therapies for such diseases requires ...

Research finds that zinc binding is vital for regulating pH levels in the brain

October 17, 2017
Researchers in Oslo, Norway, have discovered that zinc binding plays an important role in the sensing and regulation of pH in the human brain. The findings come as one of the first studies that directly link zinc binding ...

Researchers find factor that delays wound healing

October 17, 2017
New research carried out at The University of Manchester has identified a bacterium—normally present on the skin that causes poor wound healing in certain conditions.

Childhood poverty, poor support may drive up pregnant woman's biological age

October 16, 2017
Pregnant women who had low socioeconomic status during childhood and who have poor family social support appear to prematurely age on a cellular level, potentially raising the risk for complications, a new study has found.

Chronic inflammation plays critical role in sustained delivery of new muscular dystrophy therapy

October 16, 2017
Macrophages, a type of white blood cell involved in inflammation, readily take up a newly approved medication for Duchenne muscular dystrophy (DMD) and promote its sustained delivery to regenerating muscle fibers long after ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.