Featured Research

from universities, journals, and other organizations

Unlocking the metabolic secrets of the microbiome

Date:
May 4, 2011
Source:
Cell Press
Summary:
The number of bacterial cells living in and on our bodies outnumbers our own cells ten to one. But the identity of all those bugs and just what exactly our relationship to all of them really is remains rather fuzzy. Now, researchers have new evidence showing the metabolic impact of all those microbes in mice, and on their colons in particular.

The number of bacterial cells living in and on our bodies outnumbers our own cells ten to one. But the identity of all those bugs and just what exactly our relationship to all of them really is remains rather fuzzy. Now, researchers reporting in the May issue of Cell Metabolism, a Cell Press publication, have new evidence showing the metabolic impact of all those microbes in mice, and on their colons in particular.

"We point out one relatively general metabolite in the colon that has profound effects -- it does a lot to keep things running smoothly," said Scott Bultman of the University of North Carolina at Chapel Hill. And, he says, that single metabolite, known as butyrate, surely isn't all that unique. It is but one example of the complex interactions between mammals and their microbial inhabitants among many more yet to be defined.

There were already clues that the microbiome had significant effects on metabolism. For instance, earlier studies showed that "germ-free" mice have to consume 10%-30% more food to maintain their body weights compared to normal mice. Bultman's group wanted to look a little closer at where in the body those metabolic effects might be most important.

They suspected those influences might be stronger in the colon relative to other tissues, where microbes are represented in the greatest numbers. Indeed, that's exactly what they found.

Those effects were explained by the fact that cells known as colonocytes are literally fueled by bacteria-produced butyrate as their primary energy source, in place of the glucose burned by other cell types. Colonocytes taken from germ-free mice are found in an energy-deprived state, showing lower levels of important metabolic enzymes and the molecular energy currency known as ATP. Those cells manage to survive that way by digesting some of their own components in a process known as autophagy.

When the researchers added butyrate to germ-free colonocytes, it rescued their energy deficit and prevented them from undergoing autophagy, they report.

The findings come at an important time, just as efforts are underway to sequence the genomes of each and every microbe represented in the human microbiome. "As important as the Human Microbiome Project is, it is really just a launching-off point," Bultman said. "A 'parts list' of bacterial genes won't be enough. We'll need to know about the metabolites they make and their effects on energy, the immune system," and other functions.

The new insight into the important role of butyrate may also have dietary and clinical implications, the researchers say.

"Dietary factors known as prebiotics promote the growth of certain bacteria at the expense of others and have implications for human health and disease," they wrote. "As our diets have shifted away from fiber and other complex carbohydrates toward processed, simple carbohydrates, the incidences of colorectal cancer and inflammatory bowel diseases such as ulcerative colitis and Crohn's disease have increased. It is possible that increasing butyrate levels in the lumen and in colonocytes could help reverse this trend. In fact, butyrate enema therapy has been shown to ameliorate the inflammation associated with colitis in mouse models and in human clinical trials."


Story Source:

The above story is based on materials provided by Cell Press. Note: Materials may be edited for content and length.


Journal Reference:

  1. Dallas R. Donohoe, Nikhil Garge, Xinxin Zhang, Wei Sun, Thomas M. O'Connell, Maureen K. Bunger, Scott J. Bultman. The Microbiome and Butyrate Regulate Energy Metabolism and Autophagy in the Mammalian Colon. Cell Metabolism, 2011; 13 (5): 517-526 DOI: 10.1016/j.cmet.2011.02.018

Cite This Page:

Cell Press. "Unlocking the metabolic secrets of the microbiome." ScienceDaily. ScienceDaily, 4 May 2011. <www.sciencedaily.com/releases/2011/05/110503132658.htm>.
Cell Press. (2011, May 4). Unlocking the metabolic secrets of the microbiome. ScienceDaily. Retrieved September 19, 2014 from www.sciencedaily.com/releases/2011/05/110503132658.htm
Cell Press. "Unlocking the metabolic secrets of the microbiome." ScienceDaily. www.sciencedaily.com/releases/2011/05/110503132658.htm (accessed September 19, 2014).

Share This



More Health & Medicine News

Friday, September 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Could Grief Affect The Immune Systems Of Senior Citizens?

Could Grief Affect The Immune Systems Of Senior Citizens?

Newsy (Sep. 19, 2014) The study found elderly people are much more likely to become susceptible to infection than younger adults going though a similar situation. Video provided by Newsy
Powered by NewsLook.com
Jury Delivers Verdict in Salmonella Trial

Jury Delivers Verdict in Salmonella Trial

AP (Sep. 19, 2014) A federal jury has convicted three people in connection with an outbreak of salmonella poisoning five years ago that sickened hundreds of people and was linked to a number of deaths. (Sept. 19) Video provided by AP
Powered by NewsLook.com
How The 'Angelina Jolie Effect' Increased Cancer Screenings

How The 'Angelina Jolie Effect' Increased Cancer Screenings

Newsy (Sep. 19, 2014) Angelina's Jolie's decision to undergo a preventative mastectomy in 2013 inspired many women to seek early screenings for the disease. Video provided by Newsy
Powered by NewsLook.com
The Cost of Ebola

The Cost of Ebola

Reuters - Business Video Online (Sep. 18, 2014) As Sierra Leone prepares for a three-day "lockdown" in its latest bid to stem the spread of Ebola, Ciara Lee looks at the financial implications of fighting the largest ever outbreak of the disease. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins