Graduate Studies


First Advisor

Jacques Izard

Date of this Version


Document Type



A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science, Major: Food Science and Technology, Under the Supervision of Professor Jacques Izard. Lincoln, Nebraska: May, 2023

Copyright © 2023 Fan Yang


This study aimed to compare the gut microbiome of individuals with altered digestive tracts, specifically those with ileostomy or colostomy, to those with an unaltered digestive tract. Output/Fecal samples were collected from 59 participants and analyzed using 16S rRNA gene sequencing, including 17 individuals with colostomy, 20 individuals with ileostomy and 22 individuals with unaltered digestive tract serving as the control group. Results showed that individuals with colostomy had more aerobic microbes and a decrease in some beneficial bacteria, while individuals with ileostomy had a significantly different microbiome composition and functional potential compared to both the colostomy and control groups, with more facultative anaerobes and aerobic metabolism. Statistical analysis also revealed correlations between some dietary factors to gut microbes and ostomy. These findings provide us with a better understanding that how the interactions between pathogens and gut microbes contribute to the differences in disease susceptibility and fill the knowledge gap of microbiome in the small intestine. The results of this study have important implications for people’s awareness of ostomy impact and provide more reference information about the effects of ostomy on human gut microbiome.

Advisor: Jacques Izard