Colgan Hero

Sean Colgan Lab

Sean ColganOverview

The Colgan Lab studies mucosal inflammation with focus on intestinal inflammation in the context of inflammatory bowel disease and other GI diseases. Studies are aimed at understanding how epithelial and endothelial cells coordinate barrier function and inflammatory responses at mucosal surfaces. Our lab takes a multifaceted approach by investigating the relationships between gut microbiota, host immune system, genetic background, and environmental influences as it pertains to mucosal health and disease, with research emphasis on energy metabolism, host-microbe interactions, hypoxia-inducible factor, and innate immunity.

Click here for a complete list of published work in Dr. Colgan's Bibliography.

Sean Colgan,
Levine-Kern Professor of Medicine and Immunology

Sean Colgan Lab Staff


Ian Cartwright, Ph.D                 
Assistant Professor 

Ian Cartwright

A common, but often underappreciated feature of tissue inflammation is the acidification of the inflammatory microenvironment. My research is focused on furthering our understanding of the mechanisms and impact of inflammatory acidosis in the context of inflammatory bowel disease. In our recent research, we have demonstrated that neutrophil transmigration results in significant acidification of the extracellular space and that intestinal epithelial cells cope with this inflammatory acidification through the upregulation of SLC26A3, which promotes pH homeostasis. We are currently actively researching the mechanisms involved in inflammatory acidification and the impact is has on both intestinal epithelial cell function and the microbiota.

Notable Press on Ian’s work:

Alexander Dowdell, Ph.D
Postdoctoral Fellow


Alexander Dowdell

In the Colgan Lab, I research the interaction between autophagy, the intestinal epithelium, and the gut microbiota.  Previous genome-wide association studies have revealed that polymorphisms in autophagy genes confer increased susceptibility to inflammatory bowel disease (Crohn's Disease and ulcerative colitis), and that this increased susceptibility is due in part to defects in intestinal epithelial homeostasis.  In addition, the gut microbiota and microbiota-derived metabolites have been shown to positively regulate the intestinal epithelium and to protect against intestinal inflammation.  My work focuses on better understanding these interactions so as to leverage this knowledge in the development of more effective treatments for inflammatory bowel disease.

J Scott Lee, Ph.D
Assistant Professor

J Scott Lee

Metabolites across multiple classes are involved in a complex, chemically-mediated crosstalk between the gut microbiota and host tissues. In the Colgan Laboratory I am working to delineate the role of gut microbial and host-derived small molecules in microbiota-host interactions and mucosal innate immunity in health and disease. In this we work to identify new bioactive microbiota-derived compounds and determine their contribution to intestinal homeostasis. In clarifying dysbiotic and inflammatory-induced shifts from intestinal homeostasis we hope to not only further understand the metabolism of disease, but also identify new and innovative therapies for IBD.

Alfredo Ornelas Sanchez, Ph.D
Postdoctoral Fellow

Alfredo Ornelas Sanchez

We are working on the design and chemical synthesis of novel proteolysis targeting chimeras (PROTACs) for protein of interest selective degradation. Various PROTACs have been tested in vitro to monitor the degradation of our proteins of interest and their downstream effects. We are investigating potential therapeutic candidates for inflammatory bowel disease through selective protein degradation.

Geetha Bhagavatula, MD
Gastroenterology Fellow

Geetha Bhagavatula

Creatine metabolism has a vital role in the cellular energetics of many tissues. In the intestine, it has been shown that proper creatine transport is important for maintaining intestinal barrier function, and that parts of the creatine pathway may be dysregulated in inflammatory bowel disease. My work focuses on understanding the role and regulation of creatine kinase in the intestinal epithelium.

Caroline Hall, MD, Ph.D
Assistant Professor

The Hall lab works in close collaboration with the Colgan Lab due to our similar research focuses.  As a pediatric gastroenterologist, I am interested in the role of intestinal barrier and the mucosal environment on human disease.  We have focused on the function of the creatine transporter, a key regulator of energetics within the cell.  We have found that the creatine transporter is vital to intestinal epithelial barrier function and dysregulated in inflammatory bowel disease.  We continue to use a variety of in vitro and in vivo techniques to investigate the basic mechanism of epithelial function as well as working on translational research studies.

Daniel Kao, MD, Ph.D.
Assistant Professor

Dan Kao

The Kao lab is focused on the impact of purines on cell metabolism in the context of host-microbe interactions, primarily at mucosal surfaces. The lab also investigates the role of purines on bacterial stress responses and how changes in bacterial metabolism influence bacterial susceptibility to antibiotics.

Joseph Onyiah, MD
Associate Professor

Joseph Oniyah

The Onyiah lab is broadly interested in various approaches to clarify mucosal signaling directed by the innate immune system, in the context of inflammatory bowel disease. A current focus is on the influence of heme-regulated pathways in the colonic mucosa and their influence on inflammation-associated tumorigenesis. We additionally seek to understand the contribution of specific chemokines in recruiting innate immune cells to the intestinal mucosa, and how those cells differentiate based on the local microenvironment. 

Calen Steiner, MD, MS
Assistant Professor

Dan Kao

The Steiner lab works in close collaboration with the Colgan Lab due to our similar research focuses. As a gastroenterologist and inflammatory bowel disease (IBD) specialist, I am interested in understanding the cellular and molecular mechanisms of inflammation and fibrosis in IBD. We utilize many approaches to investigate these mechanisms both in vitro and in vivo. The ultimate end goal is to discover targets and develop new medical therapies for IBD patients.



Rosemary Callahan     Sam Koch 2     Nichole Welch

Rosemary Callahan                    Sam Koch                          Nichole Welch
Research Services Professional                  Research Services Professional      Research Services Senior Professional
Joseph Oniyah Lab                                      Calen Steiner Lab                            Sean Colgan Lab     

 Noah Thompson           Jake Countess               Rane Neuhart

Noah Thompson                    Jake Countess                            Rane Neuhart
Research Services Professional            Research Services Professional                  Research Services Senior Professional
Daniel Kao Lab                                      Sean Colgan Lab                                         Caroline Hall Lab  

Liheng Zhou       

Liheng Zhou                                                   
Research Services Professional                           
Sean Colgan Lab                                                                                            

Colgan Lab Contact:
12700 E.19th Ave. B146
Room 10460
Research Complex 2
Aurora, CO 80045
Lab: (720) 724-7249

Colgan Lab Alumni

Colgan Lab Alumni Update 6-17-21


Image taken on Jan 28, 2022, 12:19 PM by Lynzie Carter
Back to all images