The intestinal microbe (the community of digestive microorganisms) plays a key role in our body: it affects the development and functioning of immune, endocrine and nervous systems. Now a European project, coordinated by researchers from the Spanish National Research Council (CSIC), has shown that healthy microbes help regulate appetite, metabolism of nutrients like glucose, body weight, and obesity-related inflammation. It also demonstrates microbial influence on neurodevelopment and stress response, which in turn influences the future risk of developing chronic metabolic and psychiatric pathologies.
The project identifies new bacterial strains of the intestines that can lead to a new generation of probiotics able to fight more effectively with chronic pathologies associated with obesity and stress such as metabolic syndrome and diabetes and depression.
This project, called MyNewGut, is funded by the European Union with nine million euros and coordinated by the CSIC researcher Yolanda Sanz on the the Microbial Ecology, Nutrition and Health Group of the Institute of Agrochemistry and Food Technology (IATA), Valencia. This initiative has revealed important findings on how the intestinal microbe regulates the metabolism of nutrients and energy balance in the human body and how dieting, by its impact on microbes, can help reduce the risk of suffering from related diseases of obesity and stress.
Digestive System (Image: Pixabay)
"In this project, we have identified the characteristics of intestinal microbes, which together with diet contribute to the risk of developing obesity and its concomitant diseases, and this can help us predict it and thus we can establish preventive dietary strategies at an early stage. In particular, "in one of our studies, we have seen that the unhealthy diet reduces the microbial diversity and increases the abundance of potentially inflammatory proteobacteria (enterobacteria) in children who originally o had a normal weight and, during the study period (4 years), eventually developed overweight. On the contrary, in children who maintain normal weight, there is a decrease in this group of bacteria, explains Sanz.
In another intervention study, healthy donor microbes were transferred to individuals with metabolic syndrome by faecal transplantation. This shows that healthy microbes increase dopamine receptor expression in the brain, increase appetite control and reduce intake. "The results show for the first time in humans that the intestinal microbe has a beneficial effect on the control of the energy balance and thus improves the metabolic health by regulating the axis of the intestinal brain," explains Professor Sanz.
The MyNewGut team has also studied the effect of the amount of protein in the diet and the type of protein (animal origin such as casein or vegetable as soy protein) in overweight volunteers. "Although protein-rich diets are often effective in reducing weight, increasing protein intake also increases the proportion of protein products that reach the colon and are metabolised by colon microbes. , "Our study shows for the first time that not only the amount of protein in the diet is important but also its quality and that it leads to the production of a greater or lesser number of kidney-active metabolites of our microbial activity . This should be taken into account in future recommendations for high-protein diets, especially when they are prolonged, "the researcher adds.
MyNewGut consortium members also investigated how intestinal microbiosis that is affected by environmental lifestyles, such as the type of delivery, can influence the response to stress. In humans, they have shown that young adults born via caesarean section have an excessive response to stress compared to young people born by vaginal birth. In addition, they have shown that the use of antibiotics in the first days of life in children born via caesarean section has a negative impact on neurodevelopment.
"This is important, given the link between stress and increased risk of suffering from mental illnesses (such as depression) and metabolic diseases (such as cardiovascular pathologies), especially given that the number of cesarean births is increasing In the EU, the supply of cesarean section exceeds 30%, whereas the WHO recommends that it does not exceed 12% In the experimental models they also showed that the microbe is responsible for obesity-related depression and that its modulation (of example with probiotics or antibiotics) improves the changes in the state of the mind.
"Based on all these studies, the IATA-CSIC team has created a biopsy of human intestinal bacteria that is valuable biological material that can be used to combat obesity and related metabolic and mental complications and other future applications. in nutrition and in clinical practice, "concludes Sanz. Some of these bacteria show regular endocrine, nervous and immunological key pathways (presented in the figure) and are the origin of new patents. (Source: CSIC / DICYT)