An European project, coordinated by investigators from the Spanish National Research Council (CSIC in Spanish), has demonstrated that a healthy microbiota contributes to regulate appetite, body weight and swelling associated to obesity, besides affecting the risk of developing chronic metabolic and mental diseases. The microorganisms that live in the digestive system affect the functioning of the immunological, endocrine and nervous systems. Specifically, in one of the studies it was observed that, in 4 years of study, children with a normal weight developed obesity because an unhealthy diet decreased the diversity of this microbiota and this increased the amount of inflammatory proteobacteria. Furthermore, it was observed that this microbiota can decrease the risk of suffering diseases associated to stress.
The research also proves that not only the quantity of protein in a diet is important, but quality also is because this gives room to the production of more or less toxic metabolites in the kidney. Finally, it has been also investigated how the microbiota is affected by other things like the type of labour, proving that people born by C-section have a more exaggerated response to stress and this causes a greater risk of suffering mental and metabolic diseases.