16S rRNA Gene-Based Characterization and Functional Profiling of the Microbiome in Young Adults

Abstract

The human gut microbiota is a diverse consortium of organisms inhabiting the gut and playing an essential role in individual health. Analyzing the gut microbial composition of healthy individuals is crucial to set up a baseline for recognizing microbial dysbiosis in the case of a disorder. We aimed to characterize the microbiome of healthy young Lebanese adults through 16S rRNA gene sequencing and analysis. Forty-eight fecal samples were collected from donors in the age range of 18-25. Results obtained revealed that the dominant phyla were Firmicutes (F) and Bacteroidetes (B), followed by Proteobacteria and Tenericutes. The main common predicted metabolic functions were linked to carbohydrate metabolism and transporters. Significant segregation was observed between the microbiome of individuals with C-section versus vaginal delivery records. The microbiome, in the latter being less diverse. This study is the first of its type revealing the gut microbiome profile in young Lebanese adults. It showed a high interindividual variability despite the homogenous characteristics of the subjects. The mean F/B obtained was 1.84, falling between the mean European and the rural Africans. The high observed Firmicutes to Bacteroidetes ratio and the dominance of Bacteroides over Prevotella are associated with a diet rich in fat and proteins. An increased Proteobacteria level was linked with gut dysbiosis and reported in Type 2 diabetes, metabolic disorders, and Inflammatory Bowel Disease (IBD). This study's findings indicated the genetic heterogeneity of the donors and the diversity in Lebanese eating habits.