Find out the composition of the intestinal microbiota without using biological samples

The intestinal microbiota is the set of microorganisms that live in the intestine, such as bacteria, fungi, viruses or even parasites. It can be considered a functional organ of the human body, which in addition to promoting digestion and playing a protective role in the immune system, acts as a barrier against pathogens and toxins. The microbiota is unique and different in each person and one of the challenges of scientific research is to understand if there are universal classes of microbiota types in order to classify them into categories for each individual (also called enterotypes) and to be able to apply a more personalized medicine. A scientific team from the SEES Lab research group at the Rovira i Virgili University (URV) in Tarragona has developed a model capable of reconstructing the composition of an individual’s microbiota from partial samples and has proposed a different classification of the microbial composition to the one that existed until now.

To develop the model, they analyzed microbial compositions included in previous studies published in academic journals. “From the set of experimental data contained in these studies, we obtained matrices that gave us information on the microbial composition divided into each type or group of microbes,” explains Marta Sales-Pardo, professor in the Department of Chemical Engineering at the URV, who has participated in the research.

Until now, the classification of microbial compositions was carried out in five different groups, five enterotypes. During the investigation, they observed that there are no isolated groups of microbiota, but that they follow a nested model, that is, they work in a hierarchical way, with subsets, as if they were a Russian doll. The model that the research group has developed indicates that there is a healthy microbiota with a more general composition that contains a more varied ecosystem, and a more specialized one, with more specific microbes and bacteria.

According to Roger Guimerà, an ICREA researcher involved in this study, the new model is simple but very flexible, having shown greater reliability and precision than those that existed up to now. It allows determining whether or not a person will have a certain microbe, which facilitates the diagnosis and administration of the probiotic treatment indicated in each case. “If you take an antibiotic or a medication that affects the intestinal microbiota, with this model it will be possible to know which probiotics and which bacteria can be taken to recover it,” he concludes.

Roger Guimerà and Marta-Sales Pardo have led the investigation. (Photo: URV)

This research has been led by the SEES Lab group of the URV in collaboration with a research group from the Mayo Clinic in the United States.

The study is titled “Stochastic block models reveal a robust nested pattern in healthy human gut microbiomes”. And it has been published in the academic journal PNAS Nexus. (Source: URV)