Honors Program


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Maroney, M. 2022. Determining Pairwise Interactions to Predict Species Interactions in a Complex Community of Gut Bacteria. Undergraduate Honors Thesis. University of Nebraska-Lincoln.


Copyright Makenzie Maroney 2022.


The human gastrointestinal (GI) tract houses a diverse and expansive microbial community known as the microbiota. The relationship between the host and the microbiota is considered to be mutualistic, as trillions of bacteria that reside in the hospitable GI tract can assist in essential host functions, including contributing to metabolism and immunity against disease. An important subpopulation of the GI microbiota is the mucin-associated biofilm that is comprised of a dense layer of bacteria that forms on the GI mucin layer. The mucin layer provides an alternative niche to the GI lumen; the glycans of the mucin and the subsequent metabolites can act as a source of nutrition for many bacterial species. The biofilm can assist in microbiome resistance, resilience, and recovery and can, therefore, assist in maintaining host health. Understanding bacterial interactions that result from mucin use can lead to the development of interventions that promote microbiome stability and avoid disease development. As such, this study attempted to investigate and predict interactions between potential mucin-associated bacteria by co-culturing species in a growth medium (BRM9 + mucin liquid media) that would simulate conditions found in the mucus layer. Cultures were then plated on selective media to determine the relative growth of each bacteria species. From there, we intended to use pairwise interactions to predict species interactions in more complex communities using a mathematic model. However, the experiment was not completed due to the technical issues that arose during experimentation and lack of sufficient time. Nevertheless, the results that were obtained provided a foundation of knowledge, which can be applied to future work completed in the Auchtung Lab.

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