The gut microbiota is a complex and dynamic ecosystem with a strong influence on the host's health. Several factors can modify the gut's bacterial composition, often leading to the onset of intestinal dysbiosis. Therefore, it is essential not only to evaluate the quantitative bacterial changes occurring in the human microbiota but also to characterize relationships existing among all the microorganisms. This study aimed to evaluate the impact of bowel cleansing on the fecal microbiota network by highlighting differences between fecal microflora before and after colonoscopy, and luminal samples during colonoscopy. Fecal and luminal samples, previously analyzed by mean of Next-Generation Sequencing (NGS) for their bacterial abundance, were further processed by a method based on Artificial Neural Network (ANN) architecture. The bowel lavage had a strong effect on the intestinal microbiota network, leading to significant changes in the distribution of different bacterial hubs potentially involved in the microbiota homeostasis. Furthermore, the fecal and luminal microbiota showed a different bacterial network, characterized by distinct microbial hubs. In particular, the latter seemed to be rich in potentially pathogenic bacteria which, in physiological conditions, are counteracted by fecal microorganisms.
Keywords: Auto contractive map; Bacterial network; Colonoscopy; Gut microbiota.