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.

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 April 18, 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 April 18, 2014).

Share This



More Health & Medicine News

Friday, April 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

'Holy Grail' Of Weight Loss? New Find Could Be It

'Holy Grail' Of Weight Loss? New Find Could Be It

Newsy (Apr. 18, 2014) In a potential breakthrough for future obesity treatments, scientists have used MRI scans to pinpoint brown fat in a living adult for the first time. Video provided by Newsy
Powered by NewsLook.com
Scientists Create Stem Cells From Adult Skin Cells

Scientists Create Stem Cells From Adult Skin Cells

Newsy (Apr. 17, 2014) The breakthrough could mean a cure for some serious diseases and even the possibility of human cloning, but it's all still a way off. Video provided by Newsy
Powered by NewsLook.com
Obama: 8 Million Healthcare Signups

Obama: 8 Million Healthcare Signups

AP (Apr. 17, 2014) President Barack Obama gave a briefing Thursday announcing 8 million people have signed up under the Affordable Care Act. He blasted continued Republican efforts to repeal the law. (April 17) Video provided by AP
Powered by NewsLook.com
Is Apathy A Sign Of A Shrinking Brain?

Is Apathy A Sign Of A Shrinking Brain?

Newsy (Apr. 17, 2014) A recent study links apathetic feelings to a smaller brain. Researchers say the results indicate a need for apathy screening for at-risk seniors. 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:
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