GETTING TO KNOW THE GUT MICROBIOTA OF BUENOS AIRES CITY INHABITANTS

AYELEN ROSSO; FIORELLA SABRINA BELFORTE; PENAS STEINHARDT, ALBERTO; SOFIA QUESADA

Santiago de Chile

Congreso; XXIV Congreso Latinoamericano de Microbiologia; 2018

In recent years, the field of immunology has been revolutionized by the growing understanding of the fundamental role of microbiota in the immune system function​. In return, the immune system has evolved to maintain a symbiotic relationship with these microbes. The aim of our study was to know in depth the uncharacterized metagenome of Buenos Aires (BA) city population and its metropolitan area, being the second most populated agglomeration in the southern hemisphere. For this purpose, we evaluated 30 individuals (age: 35,23±8,26 years and BMI: 23,91±3,4 kg/m2), from the general population of BA. DNA extraction was performed from 200mg of feces using QIAamp DNA Stool Mini Kit (QG) & Quick-DNA Soil - Zymo Research (ZR) kits. The hypervariable regions V3-V4 of the bacterial 16S gene was sequenced by Macrogen (South Korea) using MiSeq-Illumina system, obtaining 47526±4718 sequences/sample. Comparing the principal phyla detected using both DNA extraction Kits, we found that the choice of DNA extraction method has an impact on the observed community structure. Using the QG kit, the dominant phyla were Bacteroidetes (47.7±8.9%), Firmicutes (37.2±8.45%), Proteobacteria (8.5±6.7%), Verrucomicrobia (2.5±2.8%) and Actinobacteria (1.3±2.2%), while the principal phyla found using ZR kit were Firmicutes (45.5±8.8%) and Bacteroidetes (40.0±7.8%), followed by Proteobacteria (6.1±5.4%), Verrucomicrobia (2.5±3.0%) and Actinobacteria (3.1±2.2%). The QG protocol, without the bead-beating step, resulted in a significantly low abundance in Gram-positive and overestimated Bacteroidetes phyla. We also compared the microbiota of BA with other westernized populations (Santiago de Chile, Rosario-Argentina, U.S.-Human-microbiome-project, Bologna-Italy) and the Hadza population of hunter-gatherer habitats. The microbiota of the BA subjects significantly differed from that of Hadza and did not differ from the subjects of the other westernized countries, being closer to the populations of Santiago de Chile. These findings contribute to promote research and comparison of the microbiome in different human populations, in order to develop more efficient therapeutic strategies for the restoration of a healthy dialogue between host and environment.