The study, published in the journal Gut Microbes also shows a link between the metabolic activity of intestinal bacteria with body mass index, fasting glucose and insulin resistance.

The intestine is inhabited by billions of bacteria that interact with each other and are known as microbiota or gut flora. "These bacteria can provide activities and molecules could not acquire for ourselves and are essential for the proper development of human beings. The age, geographic origin and other factors such as obesity and diet, pregnancy, or the use of antibiotics, can significantly alter intestinal microbial diversity, "explains Manuel Ferrer CSIC researcher who works at the Institute of Catalysis and Petroleoquímica.

The researchers first analyzed the metabolic activity of enzymes of intestinal bacteria present in stool samples of obese and thin and treated or not with antibiotics. For the first author Ester Hernandez, the study shows that obese people or a high body mass index and those treated with antibiotics have a similar metabolic behavior, which would impact on the ability to metabolize dietary sugars.

"The study suggests that the development of obesity and prolonged antibiotic treatment modifies the intestinal flora so that the enzymes become more active, which favors rapid and uneven absorption of carbohydrate and, in turn, develop obesity, eating disorders, and ultimately diabetes, "explains Ferrer.

The study lays the groundwork for future research that ultimately may enable the design of customized diets based on polysaccharides potential digestibility of the diet in terms of intestinal activity profiles to regulate weight gain. This would suggest, in particular, define the set enzimotipos or intestinal enzymes of each person and prebiotics design that ensure healthy intestinal microbiota.

"In addition, these cocktails could become part of standard treatment guidelines on antibiotic treatment in order to minimize side effects. Only through a comprehensive and detailed analysis of different antibiotics and people of different geographical origin, age or health status can develop personalized therapies and surgical interventions, "write the researchers.

The research, which has had the collaboration of the University of Granada, Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, and the Centre of Public Health Research, is part of a series of projects funded by the Ministry of Science and Innovation, the Ministry of Health, Social Services and Equality, the Instituto Carlos III and the Generalitat Valenciana. Researchers have also been supported Eranet PathoGenoMics2 program promoted by the European Union. Some of the scientists are part of the Biomedical Research Centre Network for Epidemiology and Public Health.


  • Hernández E, Bargiela R, Diez MS, Friedrichs A, Pérez-Cobas AE, Gosalbes MJ, Knecht H, Martínez-Martínez M, Seifert J, von Bergen M, Artacho A, Ruiz A, Campoy C, Latorre A, Ott SJ, Moya A, Suárez A, Martins Dos Santos VA, Ferrer M. Functional consequences of microbial shifts in the human gastrointestinal tract linked to antibiotic treatment and obesity. Gut Microbes. 4: 306-3015
  • Fotografía: Vicente Segarra taken with a Galaxy SII on July 31, 2013