Weight gain linked to poor gut bacteria

Friday, September 6, 2013. An article published online on August 28, 2013 in the journal Nature reports the MetaHIT consortium's finding of an association between gut bacterial "richness" and protection against obesity. The consortium is made up of researchers from the University of Copenhagen, China's BGI and a number of other institutes, and is coordinated by coordinated by Professor S. Dusko Ehrlich at France's Institute National de la Recherche Agronomique.

The current research compared the gut bacterial genes of 169 obese and 123 nonobese Danish men and women. It was discovered that approximately one-fourth of the participants had up to 40% fewer gut bacterial genes than the remainder of the study population and correspondingly fewer bacteria. This group also had less bacterial diversity. Subjects with low bacterial richness were significantly likely to have more adiposity or to be obese, and to have gained more weight over the previous nine years. They were also more insulin resistant, more likely to be dyslipidemic, and had an increase in markers of inflammation and white blood cells, indicating a greater risk for diabetes or heart disease. The research team identified eight bacterial species as possibly preventive against weight gain. The findings could lead to new therapies for obesity or the development of diagnostic tests to identify those at risk of diseases linked to gut microbiome alterations.

In another article appearing on August 28 in Nature, members of the ANR MicroObes consortium report that a low fat diet improved microbial gene richness, in both diversity and numbers. "This indicates that you can repair some of the damage to your gut bacteria simply by changing your dietary habits," remarked Oluf Pedersen who co-headed the Danish portion of the MetaHIT project. "Our intestinal bacteria are actually to be considered an organ just like our heart and brain, and the presence of health-promoting bacteria must therefore be cared for in the best way possible. Over the next years, we will be gathering more knowledge of how best to do this."

"The long-term dream is to map and characterize any naturally occurring gut bacteria that produce appetite-inhibiting bioactive substances and in this way learn to exploit the body's own medicine to prevent the obesity epidemic and type 2 diabetes," he added.

"At present we cannot do anything about our own DNA, individual variation which also plays a crucial role in susceptibility for lifestyle diseases," Dr Pederson noted. "But thanks to the new gut microbiota research, we now can start exploring interactions between host genetics and the gut bacteria- related environment which we may be able to change. That is why it is so exciting for us scientists within this research field– the possibilities are huge."