Weight gain influences intestinal bacteria and metabolite patterns

An increase in body weight is accompanied by changes in both the composition of gut microbiota and the pattern of thousands of metabolites. In addition, diabetes appears to influence certain metabolic pathways, such as sulfur metabolism. Scientists from the Helmholtz Zentrum München, a partner in the DZD, used metabolomic analyses to examine these effects and consequently have again pointed out the complexity of intestinal metabolism. The results have been published in 'The ISME Journal' and 'The Journal of Proteome Research'.

Weight gain also has an impact on metabolism and on the bacterial community composition in the gastrointestinal tract. A team of scientists from the Helmholtz Zentrum München, the Technische Universität München (TUM) and the University of Vienna discovered that excess weight in mice influences the composition of the gut microbiota. The research projects were funded by the German Center for Diabetes Research (DZD). The team headed by Alesia Walker and Prof. Dr. Philippe Schmitt-Kopplin were especially interested in the discovery of altered metabolic products (metabolites) in association with weight gain. They compared the metabolic profiles and the diversity and composition of the gut microbiota in healthy mice to those in overweight mice. Only less than ten percent of thousands of detected metabolites are known and given in metabolite databases.

"Excess weight directly influences metabolic performance"
"Our results show the complexity of metabolic regulation and control, and also that excess weight directly influences gut metabolism," reports study leader Schmitt-Kopplin. "Our measurements using ultra-high resolution mass spectrometry are providing us insights into metabolic changes that have not yet been described. These results indicate which molecular mechanisms could underlie excess weight and could contribute to secondary outcomes."

Diabetes associated with altered sulfur compounds
Particularly, the so-called gut microbiome, the composition of microorganisms in the intestines, has long been associated with the development of various diseases, such as diabetes mellitus, for example. In a further study, the group headed by Schmitt-Kopplin was able to show that the metabolism in a diabetic animal model is especially characterized by new types of sulfur-containing metabolites. "In both studies we were able to reveal various metabolic patterns and even identify metabolites, which were unknown before. Now, we want to examine their functions further, with a special focus on sulfur metabolism," explains first author Walker. "The comparison with the gut microbiota furthermore allows us to conclude about the body's metabolic characteristics and microbial-metabolic interactions."

Original publications:
Walker, A. et al. (2014): Distinct signatures of host–microbial meta-metabolome and gut microbiome in twoQ1 C57BL/6 strains under high-fat diet, The ISME Journal (International Society for Microbial Ecology), doi: 10.1038/ismej.2014.79
Link to publication

Walker, A. et al. (2014): The importance of sulfur-containing metabolites in discriminating fecal extracts between normal and type 2 diabetic mice, Journal of Proteome Research, doi: 10.1021/pr500046b
Link to publication