Changes in gut microbiota after unhealthy diet may protect from metabolic disease

March 17, 2017

An unhealthy diet changes the composition of the gut flora and it is generally assumed that this maladaptation called "dysbiosis" triggers disease. A study by Matteo Serino and his colleagues at the Université Paul Sabatier in Toulouse, France, now challenges this view. Using mice as a model organism, the researchers show that dysbiosis may have beneficial effects on liver metabolism and may protect against metabolic disease. The study is published today in Molecular Systems Biology.

The intestine is covered with a plethora of microorganisms, collectively termed gut microbiota, that are thought to play an important role in regulating the metabolism and shaping the . Many studies have shown that dysbiotic bacteria can cause disease. However, these studies generally follow a similar protocol that may impact on the outcome: They transfer dysbiotic bacteria to axenic mice that do not have any microbiota. For example, axenic mice that receive microbiota from the gut of would increase their total body fat, indicating that microbiota play a causative role in the development of obesity.

Serino and his colleagues now took a different approach to addressing the role of microbiota. The researchers reasoned that axenic mice are ill-equipped to deal with dysbiotic microbiota. Their gut barrier is impaired, favoring an uncontrolled spread of bacteria throughout the body. In addition, their immune system is not well developed. Thus, instead of using axenic mice as recipients of dysbiotic microbiota, the team used normal, healthy mice, which have not been treated with antibiotics before. In contrast to previous research, the team found that a dysbiosis is not necessarily harmful. In fact, it may even lead to metabolic adaptions that protect the body against disease.

High fat diet increases the production of glucose by the liver and can eventually lead to . However, when Serino and his colleagues transplanted dysbiotic microbiota from mice on high-fat diet to healthy mice, they found that the production of glucose in the liver was reduced rather than increased. Therefore, dysbiotic microbiota counter the metabolic effect of high-fat diet and may thus protect the host from its consequences. Similar effects were also observed when the researchers used microbiota from genetically obese mice.

In another set of experiments, the researchers transplanted dysbiotic microbiota from obese mice to healthy mice and then put these mice on a high-fat diet. Normally, a high-fat would lead to weight gain. However, the body mass of that had received dysbiotic microbiota did not change, and their adipose tissue showed smaller fat cells, consistent with increased plasma free-fatty acids.

In conclusion, dysbiosis after may not all be detrimental. As long as the gut barrier is intact and the immune system is functional, dysbiosis may even protect the body from metabolic effects of unhealthy diets. "Our observation may encourage a new debate on the role of dysbiosis in the induction of metabolic diseases," said Serino.

Explore further: From mice, clues to microbiome's influence on metabolic disease

More information: Simon Nicolas et al. Transfer of dysbiotic gut microbiota has beneficial effects on host liver metabolism, Molecular Systems Biology (2017). DOI: 10.15252/msb.20167356

Related Stories

From mice, clues to microbiome's influence on metabolic disease

February 17, 2017
The community of microorganisms that resides in the gut, known as the microbiome, has been shown to work in tandem with the genes of a host organism to regulate insulin secretion, a key variable in the onset of the metabolic ...

Gut bacteria may play a role in Alzheimer's disease

February 10, 2017
New research from Lund University in Sweden has shown that intestinal bacteria can accelerate the development of Alzheimer's disease. According to the researchers behind the study, the results open up the door to new opportunities ...

Researchers find unhealthy gut microbes a cause of hypertension

February 3, 2017
Researchers have found that the microorganisms residing in the intestines (microbiota) play a role in the development of high blood pressure in rats. The study is published in Physiological Genomics. It was chosen as an APSselect ...

Your microbiota's previous dining experiences may make new diets less effective

December 29, 2016
Your microbiota may not be on your side as you try improving your diet this New Year's. In a study published December 29 in Cell Host & Microbe, researchers explore why mice that switch from an unrestricted American diet ...

Researchers target gut bacteria to reduce weight gain

August 29, 2016
A new therapy that involves engineered gut bacteria may one day help reduce the health problems that come with obesity. Incorporating the engineered bacteria into the guts of mice both kept them from gaining weight and protected ...

Gut microbiota transplantation may prevent development of diabetes and fatty liver disease

April 19, 2012
Exciting new data presented today at the International Liver Congress 2012 shows the gut microbiota's causal role in the development of diabetes and non-alcoholic fatty liver disease (NAFLD), independent of obesity.(1) Though ...

Recommended for you

Want to win at sports? Take a cue from these mighty mice

July 20, 2017
As student athletes hit training fields this summer to gain the competitive edge, a new study shows how the experiences of a tiny mouse can put them on the path to winning.

'Smart' robot technology could give stroke rehab a boost

July 19, 2017
Scientists say they have developed a "smart" robotic harness that might make it easier for people to learn to walk again after a stroke or spinal cord injury.

Engineered liver tissue expands after transplant

July 19, 2017
Many diseases, including cirrhosis and hepatitis, can lead to liver failure. More than 17,000 Americans suffering from these diseases are now waiting for liver transplants, but significantly fewer livers are available.

Lunatic Fringe gene plays key role in the renewable brain

July 19, 2017
The discovery that the brain can generate new cells - about 700 new neurons each day - has triggered investigations to uncover how this process is regulated. Researchers at Baylor College of Medicine and Jan and Dan Duncan ...

New animal models for hepatitis C could pave the way for a vaccine

July 19, 2017
They say that an ounce of prevention is worth a pound of cure. In the case of hepatitis C—a disease that affects nearly 71 million people worldwide, causing cirrhosis and liver cancer if left untreated—it might be worth ...

Omega-3 fatty acids fight inflammation via cannabinoids

July 18, 2017
Chemical compounds called cannabinoids are found in marijuana and also are produced naturally in the body from omega-3 fatty acids. A well-known cannabinoid in marijuana, tetrahydrocannabinol, is responsible for some of its ...

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.