CB24 - The Influence of Dietary Carbohydrates on Gene Activity and Antibiotic Tolerance in Gut Bacteria
SCURS Disciplines
Microbiology
Document Type
General Poster
Invited Presentation Choice
Service-Learning — Oral
Abstract
In the human gut, bacterial behavior is strongly shaped by environmental conditions, including diet. One influential factor is the availability of dietary carbohydrates, which represents a major component of daily human nutrition and serves as a primary energy source for many gut microbes. Carbohydrates range from simple sugars such as glucose to more complex molecules like maltose and pullulan, for which their structural diversity requires specialized bacterial systems for recognition, transport, and utilization. Changes in carbohydrate availability may therefore influence not only bacterial growth, but also host-microbe interactions and bacterial responses to environmental stressors such as antibiotics. Previous research has demonstrated that Bacteroides thetaiotaomicron exhibits altered growth and increased resistance to the antibiotic amoxicillin when grown in the presence of certain carbohydrates, suggesting that nutrient availability may modulate antibiotic resistance in this genus. However, it remains unclear whether this carbohydrate-dependent phenomenon extends to other gut-associated Bacteroides species, particularly those with clinically relevant virulence potential. This research focuses on Bacteroides fragilis, a common member of the human gut microbiome that contributes to normal gut function and acts as an opportunistic pathogen under the right conditions. Notably, B. fragilis possesses carbohydrate utilization systems that are important to gut colonization and may affect bacterial behaviors relevant to host interaction and pathogenic potential. This study builds on prior findings by investigating whether differences in carbohydrate availability alters antibiotic resistance in B. fragilis and whether such changes can be explained by alterations of carbohydrate gene expression within the starch utilization system (sus), which are involved in sensing and importing complex carbohydrates. Gene activity will be assessed by measuring mRNA levels using RT-qPCR, providing a direct measure of carbohydrate-related gene expression under different nutrient conditions. By integrating gene expression analysis with the results of antibiotic response to ampicillin, this project aims to clarify whether carbohydrate utilization influences bacterial traits relevant to survival and virulence. Overall, this research emphasizes the role of dietary carbohydrates in shaping host-microbe interactions and also highlights how environmental nutrient availability may directly influence antibiotic resistance and pathogenic potential in gut bacteria.
Keywords
Antibiotic resistance, Gut microbiome, Dietary carbohydrates, Bacteroides fragilis, Gene expression, sus operon, Nutrient environment, and Antibiotic response
Start Date
10-4-2026 9:30 AM
Location
University Readiness Center Greatroom
End Date
10-4-2026 11:30 AM
CB24 - The Influence of Dietary Carbohydrates on Gene Activity and Antibiotic Tolerance in Gut Bacteria
University Readiness Center Greatroom
In the human gut, bacterial behavior is strongly shaped by environmental conditions, including diet. One influential factor is the availability of dietary carbohydrates, which represents a major component of daily human nutrition and serves as a primary energy source for many gut microbes. Carbohydrates range from simple sugars such as glucose to more complex molecules like maltose and pullulan, for which their structural diversity requires specialized bacterial systems for recognition, transport, and utilization. Changes in carbohydrate availability may therefore influence not only bacterial growth, but also host-microbe interactions and bacterial responses to environmental stressors such as antibiotics. Previous research has demonstrated that Bacteroides thetaiotaomicron exhibits altered growth and increased resistance to the antibiotic amoxicillin when grown in the presence of certain carbohydrates, suggesting that nutrient availability may modulate antibiotic resistance in this genus. However, it remains unclear whether this carbohydrate-dependent phenomenon extends to other gut-associated Bacteroides species, particularly those with clinically relevant virulence potential. This research focuses on Bacteroides fragilis, a common member of the human gut microbiome that contributes to normal gut function and acts as an opportunistic pathogen under the right conditions. Notably, B. fragilis possesses carbohydrate utilization systems that are important to gut colonization and may affect bacterial behaviors relevant to host interaction and pathogenic potential. This study builds on prior findings by investigating whether differences in carbohydrate availability alters antibiotic resistance in B. fragilis and whether such changes can be explained by alterations of carbohydrate gene expression within the starch utilization system (sus), which are involved in sensing and importing complex carbohydrates. Gene activity will be assessed by measuring mRNA levels using RT-qPCR, providing a direct measure of carbohydrate-related gene expression under different nutrient conditions. By integrating gene expression analysis with the results of antibiotic response to ampicillin, this project aims to clarify whether carbohydrate utilization influences bacterial traits relevant to survival and virulence. Overall, this research emphasizes the role of dietary carbohydrates in shaping host-microbe interactions and also highlights how environmental nutrient availability may directly influence antibiotic resistance and pathogenic potential in gut bacteria.