Unravelling the role of Bacteroides and Phocaeicola in the human gut: exploring evolutionary dynamics, mother-to-infant vertical transmission, and functional characteristics
type: CreativeWork
description: The human gut microbiota is composed of trillions of microrganims and plays a major role in human health and disease by performing a series of physiological functions, such as protection against pathogens, energy production, maintenance of intestinal barrier integrity, and regulation of the immune system. Bacteroides is one of the major genera present in the human gut. Bacteroides colonise the gut soon after birth in vaginally born babies and its abundance increases after weaning. However, different studies have shown that Bacteroides are missing or present in lower relative abundance in infants born by caesarean section (CS). Lower Bacteroides relative abundance has been associated with higher risk of atopic sensitization, especially in children of Asian heritage. Bacteroides and Phocaeicola have been linked to both health and disease. In the gut, Bacteroides is often associated with health benefits, but it can become an opportunistic pathogen in other body sites. Herein, this thesis explored a number of research topics aimed at gaining a better understanding of the role of Bacteroides and Phocaeicola in the human gut, such as production of metabolites, genetic and evolutionary features, vertical transfer, persistence and relative abundance of Bacteroides and Phocaeicola in early life. Characterization of a new species of Bacteroides and a potential Phocaeicola probiotic strain were also carried out. In Chapter 1, the current knowledge about the association of Bacteroides and Phocaeicola with health and disease was explored. Metabolic conditions associated with altered levels of these species, as well as their role as opportunistic pathogens and the challenges associated with the use of Bacteroides and Phocaeicola as probiotic were investigated. Numerous pre-clinical studies showed the benefits of strains of Bacteroides and Phocaeicola in various conditions, however, more clinical research is needed to evaluate if these benefits extend to humans. Chapter 2 explores…
abstract: The human gut microbiota is composed of trillions of microrganims and plays a major role in human health and disease by performing a series of physiological functions, such as protection against pathogens, energy production, maintenance of intestinal barrier integrity, and regulation of the immune system. Bacteroides is one of the major genera present in the human gut. Bacteroides colonise the gut soon after birth in vaginally born babies and its abundance increases after weaning. However, different studies have shown that Bacteroides are missing or present in lower relative abundance in infants born by caesarean section (CS). Lower Bacteroides relative abundance has been associated with higher risk of atopic sensitization, especially in children of Asian heritage. Bacteroides and Phocaeicola have been linked to both health and disease. In the gut, Bacteroides is often associated with health benefits, but it can become an opportunistic pathogen in other body sites. Herein, this thesis explored a number of research topics aimed at gaining a better understanding of the role of Bacteroides and Phocaeicola in the human gut, such as production of metabolites, genetic and evolutionary features, vertical transfer, persistence and relative abundance of Bacteroides and Phocaeicola in early life. Characterization of a new species of Bacteroides and a potential Phocaeicola probiotic strain were also carried out. In Chapter 1, the current knowledge about the association of Bacteroides and Phocaeicola with health and disease was explored. Metabolic conditions associated with altered levels of these species, as well as their role as opportunistic pathogens and the challenges associated with the use of Bacteroides and Phocaeicola as probiotic were investigated. Numerous pre-clinical studies showed the benefits of strains of Bacteroides and Phocaeicola in various conditions, however, more clinical research is needed to evaluate if these benefits extend to humans. Chapter 2 explores…
author: da Silva Morais, Emilene
language: en
keywords: Bacteroides, Phocaeicola, Probiotics, Mode of delivery, Early life, Gut microbiobe, Pan-genome, Metagenomics, Vertical transmission
license: https://creativecommons.org/licenses/by-nc-nd/4.0/
date published: 2023
date modified: 2026-07-24T01:46:08Z
provider: University College Cork
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University College Cork

PropertyValue
property ID: Handle
value: https://hdl.handle.net/10468/16474