The Role of the Gut Microbiome in Gastrointestinal Disorders

Michael W. Dougherty

PhD Candidate, UF College of Medicine

Abstract: A symbiotic community of microbes containing an estimated 1014 bacteria colonizes the human gastrointestinal tract, roughly equivalent to the total number of mammalian cells. Under healthy conditions, these bacterial communities promote intestinal homeostasis by helping to digest food, regulate host metabolism, maintain immune tolerance, and enable tissue maturation or function. The advent of next-generation sequencing has allowed researchers to catalog how microbial community composition and function change during the progression of various gastrointestinal diseases, including colorectal cancer (CRC). Broadly, these studies have shown that specific bacterial taxa are associated with the promotion of or protection against CRC. For example, some bacteria potentially introduce cancer-initiating mutations by producing microbial genotoxins while others produce metabolites that interfere with core metabolic processes in cancer cells. Moreover, the bacterial species present within the intestinal tract alter local and systemic cellular or metabolic profiles to influence treatment efficacy. Collectively, these findings have resulted in the inclusion of microbial dysbiosis as one of the hallmarks of cancer. Recent research suggests that interventions aimed at manipulating the intestinal microbiome to prevent disease or enhance cancer therapies may be a viable means of improving clinical outcomes.

Michael Dougherty is a PhD candidate in that laboratory of Dr. Christian Jobin at the UF College of Medicine. His research focuses on elucidating the structure-function relationship of a proposed microbial toxin that has been implicated in the development of colorectal cancer. In his work, he utilizes novel techniques (mutational signature analysis, CRISPR-Cas9 gene editing, human-derived organoids, and metabolomics imaging) to reveal the mechanisms underlying host-bacteria interactions.

Core Standards

SC.912.N.1.4 Identify sources of information and assess their reliability according to the strict standards of scientific investigation.

SC.912.N.1.6 Describe how scientific inferences are drawn from scientific observations and provide examples from the content being studied.

SC.912.N.2.5 Describe instances in which scientists’ varied backgrounds, talents, interests, and goals influence the inferences and thus the explanations that they make about observations of natural phenomena and describe that competing interpretations (explanations) of scientists are a strength of science as they are a source of new, testable ideas that have the potential to add new evidence to support one or another of the explanations.

SC.912.L.14.46 Describe the physiology of the digestive system, including mechanical digestion, chemical digestion, absorption and the neural and hormonal mechanisms of control.

SC.912.L.16.7 Describe how viruses and bacteria transfer genetic material between cells and the role of this process in biotechnology.


NCI Cancer Center badge