Geography, diet and host’s lifestyle shape the human gut microbiota

Abstract

The microbiota, defined as the collection of bacteria inhabiting a specific ecological niche, is an expanding field of research. Microbiota itself is ubiquitous and significantly impacts a wide range of domains, including human beings as well as all the currently known environments. Recent research endeavors have highlighted the pivotal role played by bacterial communities in human lives, which is manifested through direct and indirect interactions. Nevertheless, despite sharing similar environmental conditions, the microbiota composition associated with a specific niche usually shows a high degree of variability, and this biodiversity is the source of various translational trial applications. The gut microbiota, among the many types of human-related microbiota, has caught the interest of researchers due to its deep complexity and high level of interaction with the human host. Actually, the human gut microbiota is regarded as one of the key variables that may affect the outcome of oral drug treatment, as well as metabolism and even brain functionality with psychological implications. For these reasons, comprehensive investigations of the gut microbiota composition in infants and adults led in the past decades to the identification of specific recurring bacterial communities in healthy subjects while correlating some bacterial taxa with the onset of specific disorders and the presence of chronic diseases. These correlations between the bacterial composition of the human gut and health status highlight the potential outcomes that could be achieved by exploiting the enhanced availability of gut microbiome data. Overall, studying the correlation between bacterial prevalence, abundance and correlation with the human host’s health status now offers valuable insights into the role of the human microbiota that will drive the progress of personalized medicine supporting human well-being. The underlying basis of my Ph.D. lies in examining microbial compositions associated with the human gut and accompanied by specific metadata such as age, geographical location, and lifestyle, as well as developing novel bioinformatic tools for data analysis. Furthermore, given that diet is one of the most complex factors capable of influencing the composition of the human gut, a thorough investigation into the role of fermented foods in delivering bacterial strains to the human gut was conducted.