Effects of antibiotics on gut flora analyzed

In the gut live one trillion bacteria, which are known as microbiota or gut flora, and that have co-evolved in symbiosis with humans. According to this study, treatment with antibiotics can alter this symbiosis from early stages of the treatment. "Although some of the changes are oscillatory and can be reversed at the end of the treatment, others seem irreversible," says one of the coordinators of the study, Andrés Moya, who works at Cavanilles Institute of Biodiversity and Evolutionary Biology of the Science Park of the Universitat de València.

The research, which has had the collaboration of the CSIC, the Centre Superior d'Investigació en Salut Pública (CSISP) (Centre for Advanced Research in Public Health), the University CEU San Pablo and the Centre d'Investigació Biomèdica en Xarxa en Epidemiologia i Salut Pública (CIBEResp) (Centre for Biomedical Research in Epidemiology and Public Health), has compared stool samples of a patient taken before and after the treatment.

Changes in gut bacteria

The biodiversity of the bacteria that form the gut microbiota, according to the results, decreases during the treatment to the point of reaching its minimum 11 days after the beginning. However, at the end of the treatment, the situation is reversed and the patient presents a bacterial population similar to the first.

Although the research "shows for the first time that gut bacteria presents a lower capacity to produce proteins, as well as deficiencies in key activities, during and after the treatment," explains Moya. Specifically, the study suggests that the gut microbiota shows less capacity to absorb iron, digest certain foods and produce essential molecules for the organism.

The research also shows that less abundant bacteria in the gut flora, but little active at the beginning of the treatment, at the end they became active and they may play an important role in the gut as a consequence of the antibiotics, according to Manuel Ferrer, researcher of the CSIC. "These bacteria could be responsible for improving the interconnection between the liver and colon and of the production of essential molecules such as bile acids, hormones and cholesterol derivatives," say the researchers.

"Personalized therapies and interventions can only be reached through a comprehensive and detailed analysis of the different antibiotics and people from different geographical origin, age or state of health," concludes Moya.