Featured Research

from universities, journals, and other organizations

Very Low Carbohydrate Diets May Disrupt Long-term Gut Health

Date:
June 20, 2007
Source:
Rowett Research Institute
Summary:
Scientists have shown that a very low carbohydrate weight-loss diet results in a four-fold reduction in the numbers of certain types of bacteria in the gut of obese men. This is a significant finding because these gut bacteria produce a substance called butyrate, which has been shown to be important for keeping the gut healthy including helping to prevent colorectal cancer.

Scientists at Aberdeen’s Rowett Research Institute have shown that a very low carbohydrate weight-loss diet results in a four-fold reduction in the numbers of certain types of bacteria in the gut of obese men.

Related Articles


This is a significant finding because these gut bacteria produce a substance called butyrate, which has been shown to be important for keeping the gut healthy including helping to prevent colorectal cancer. The study raises questions about the impact of the prolonged use of very low-carbohydrate weight-loss diets on gut health.

Very low-carbohydrate weight-loss diets (such as the so-called ‘Atkins-type diets) are popular with people struggling to lose weight and are used in some weight-loss clinics. Nutritionists have raised concerns about the low fruit and vegetable content of such diets as these contain nutrients that help protect against a number of diseases and cancers within the body. Less attention has been paid to the consequences of the low carbohydrate intake on the bacteria within the gut and how this might alter the release of either beneficial or harmful compounds from the food.

In this study, 19 healthy, obese men were given three diets containing different levels of carbohydrate (high, medium and low). Two of the diets also contained a high proportion of protein, as this is known to help reduce appetite and is used in a number of diets that help produce weight loss. Indeed, the volunteers lost similar amounts of weight and body fat on these two diets. Stool samples were analysed for the amount and type of bacteria, and for butyrate.

“The changes in butyrate production that we observed in this study are the largest ever reported in a human dietary trial. The results provide strong evidence that butyrate production is largely determined by the content of a particular type of carbohydrate in the diet that the bacteria in our guts can utilise,” said Professor Harry Flint who led the research at the Rowett Institute.

“We can’t be sure from this study about the impact of butyrate production on gut health, but there has been quite a lot of work done which shows that butyrate stops cancer cells from growing, and so helps prevent colorectal cancer.

“If low carbohydrate diets are to be consumed for long periods of time, it may be important to ensure that there is enough of the right sort of carbohydrate in the diet which can be used by the bacteria to produce compounds such as butyrate, which are beneficial for human health. This means making sure you continue to eat plenty of sources of fibre – such as fruit and vegetables,” said Professor Harry Flint.

What is butyrate?

Butyrate is what is known as a short chain fatty acid, and is produced in the gut when the bacteria ferment the carbohydrate present in food. It can be used by the bacteria as a source of energy and also is used by the cells which line the gut wall. Studies have shown that butyrate can prevent cancer cells in the gut from continuing to grow and so reduce the risk of colorectal cancer.

The composition of the three diets was as follows:

Normal (maintenance) diet: 13% protein, 52% carbohydrate, 35% fat, as calories;

Medium carbohydrate diet: 30% protein, 35% carbohydrate, 35% fat. as calories

Low carbohydrate diet: 30% protein, 4% carbohydrate, 66% fat, as calories.

The work is published in Applied and Environmental Microbiology, 73:1073-8.


Story Source:

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


Cite This Page:

Rowett Research Institute. "Very Low Carbohydrate Diets May Disrupt Long-term Gut Health." ScienceDaily. ScienceDaily, 20 June 2007. <www.sciencedaily.com/releases/2007/06/070619173537.htm>.
Rowett Research Institute. (2007, June 20). Very Low Carbohydrate Diets May Disrupt Long-term Gut Health. ScienceDaily. Retrieved November 28, 2014 from www.sciencedaily.com/releases/2007/06/070619173537.htm
Rowett Research Institute. "Very Low Carbohydrate Diets May Disrupt Long-term Gut Health." ScienceDaily. www.sciencedaily.com/releases/2007/06/070619173537.htm (accessed November 28, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Friday, November 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Rural India's Low-Cost Sanitary Pad Revolution

Rural India's Low-Cost Sanitary Pad Revolution

AFP (Nov. 28, 2014) — One man hopes his invention -– a machine that produces cheap sanitary pads –- will help empower Indian women. Duration: 01:51 Video provided by AFP
Powered by NewsLook.com
Research on Bats Could Help Develop Drugs Against Ebola

Research on Bats Could Help Develop Drugs Against Ebola

AFP (Nov. 28, 2014) — In Africa's only biosafety level 4 laboratory, scientists have been carrying out experiments on bats to understand how virus like Ebola are being transmitted, and how some of them resist to it. Duration: 01:18 Video provided by AFP
Powered by NewsLook.com
Ebola Leaves Orphans Alone in Sierra Leone

Ebola Leaves Orphans Alone in Sierra Leone

AFP (Nov. 27, 2014) — The Ebola epidemic sweeping Sierra Leone is having a profound effect on the country's children, many of whom have been left without any family members to support them. Duration: 01:02 Video provided by AFP
Powered by NewsLook.com
Experimental Ebola Vaccine Shows Promise In Human Trial

Experimental Ebola Vaccine Shows Promise In Human Trial

Newsy (Nov. 27, 2014) — A recent test of a prototype Ebola vaccine generated an immune response to the disease in subjects. Video provided by Newsy
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

 

Health & Medicine

Mind & Brain

Living & Well

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