Featured Research

from universities, journals, and other organizations

Waste From Gut Bacteria Helps Host Control Weight, Researchers Report

Date:
October 19, 2008
Source:
UT Southwestern Medical Center
Summary:
A single molecule in the intestinal wall, activated by the waste products from gut bacteria, plays a large role in controlling whether the host animals are lean or fatty, a research team has found in a mouse study.

Dr. Masashi Yanagisawa.
Credit: UT Southwestern Medical Center

A single molecule in the intestinal wall, activated by the waste products from gut bacteria, plays a large role in controlling whether the host animals are lean or fatty, a research team, including scientists from UT Southwestern Medical Center, has found in a mouse study.

Related Articles


When activated, the molecule slows the movement of food through the intestine, allowing the animal to absorb more nutrients and thus gain weight. Without this signal, the animals weigh less.

The study shows that the host can use bacterial byproducts not only as a source of nutrients, but also as chemical signals to regulate body functions. It also points the way to a potential method of controlling weight, the researchers said.

"It's quite possible that blocking this receptor molecule in the intestine might fight a certain kind of obesity by blocking absorption of energy from the gut," said Dr. Masashi Yanagisawa, professor of molecular genetics at UT Southwestern and a senior co-author of the study, which appears online in Proceedings of the National Academy of Sciences.

Humans, like other animals, have a large and varied population of beneficial bacteria that live in the intestines. The bacteria break up large molecules that the host cannot digest. The host in turn absorbs many of the resulting small molecules for energy and nutrients.

"The number of bacteria in our gut far exceeds the total number of cells in our bodies," said Dr. Yanagisawa.

"It's truly a mutually beneficial relationship. We provide the bacteria with food, and in return they supply energy and nutrients," he explained.

Using mice, the researchers focused on two species of bacteria that break up dietary fibers from food into small molecules called short-chain fatty acids. Dr. Yanagisawa's team previously had found that short-chain fatty acids bind to and activate a receptor molecule in the gut wall called Gpr41, although little was known about the physiological outcome of Gpr41 activation.

The researchers disrupted communication between the bacteria and the hosts in two ways: raising normal mice under germ-free conditions so they lacked the bacteria, and genetically engineering other mice to lack Gpr41 so they were unable to respond to the bacteria.

In both cases, the mice weighed less and had a leaner build than their normal counterparts even though they all ate the same amount.

The researchers also found that in mice without Gpr41, the intestines passed food more quickly. They hypothesized that one action of Gpr41 is to slow down the motion that propels food forward, so that more nutrients can be absorbed. Thus, if the receptor cannot be activated, food is expelled more quickly, and the animal gets less energy from it.

Because mice totally lacking Gpr41 were still healthy and had intestinal function, the receptor may be a likely target for drugs that can slow, but not stop, energy intake, Dr. Yanagisawa said.

Other UT Southwestern researchers involved in the study were co-lead author and graduate student Abdullah Shaito; Dr. Toshiyuki Motoike, assistant professor of molecular genetics; research specialist Clay Willams; and Dr. Robert Hammer, professor of biochemistry. Researchers from Washington University School of Medicine, the Japan Science and Technology Agency and Howard Hughes Medical Institute in Chevy Chase, Md., also participated.

The study was funded by the National Science Foundation, the National Institutes of Health, the W.M. Keck Foundation, the Japan Science and Technology Agency and HHMI.


Story Source:

The above story is based on materials provided by UT Southwestern Medical Center. Note: Materials may be edited for content and length.


Cite This Page:

UT Southwestern Medical Center. "Waste From Gut Bacteria Helps Host Control Weight, Researchers Report." ScienceDaily. ScienceDaily, 19 October 2008. <www.sciencedaily.com/releases/2008/10/081018093223.htm>.
UT Southwestern Medical Center. (2008, October 19). Waste From Gut Bacteria Helps Host Control Weight, Researchers Report. ScienceDaily. Retrieved December 22, 2014 from www.sciencedaily.com/releases/2008/10/081018093223.htm
UT Southwestern Medical Center. "Waste From Gut Bacteria Helps Host Control Weight, Researchers Report." ScienceDaily. www.sciencedaily.com/releases/2008/10/081018093223.htm (accessed December 22, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Monday, December 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Earthworms Provide Cancer-Fighting Bacteria

Earthworms Provide Cancer-Fighting Bacteria

Reuters - Innovations Video Online (Dec. 21, 2014) — Polish scientists isolate bacteria from earthworm intestines which they say may be used in antibiotics and cancer treatments. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Existing Chemical Compounds Could Revive Failing Antibiotics, Says Danish Scientist

Existing Chemical Compounds Could Revive Failing Antibiotics, Says Danish Scientist

Reuters - Innovations Video Online (Dec. 21, 2014) — A team of scientists led by Danish chemist Jorn Christensen says they have isolated two chemical compounds within an existing antipsychotic medication that could be used to help a range of failing antibiotics work against killer bacterial infections, such as Tuberculosis. Jim Drury went to meet him. Video provided by Reuters
Powered by NewsLook.com
Researchers Test Colombian Village With High Alzheimer's Rates

Researchers Test Colombian Village With High Alzheimer's Rates

AFP (Dec. 19, 2014) — In Yarumal, a village in N. Colombia, Alzheimer's has ravaged a disproportionately large number of families. A genetic "curse" that may pave the way for research on how to treat the disease that claims a new victim every four seconds. Duration: 02:42 Video provided by AFP
Powered by NewsLook.com
Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Reuters - Light News Video Online (Dec. 19, 2014) — Millions of monarch butterflies begin to descend onto Mexico as part of their annual migration south. Rough Cut (no reporter narration) 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:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

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