Browsing by Author "Britton, Robert A."

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    A novel system to culture human intestinal organoids under physiological oxygen content to study microbial-host interaction
    (Public Library of Science, 2024) Fofanova, Tatiana Y.; Karandikar, Umesh C.; Auchtung, Jennifer M.; Wilson, Reid L.; Valentin, Antonio J.; Britton, Robert A.; Grande-Allen, K. Jane; Estes, Mary K.; Hoffman, Kristi; Ramani, Sashirekha; Stewart, Christopher J.; Petrosino, Joseph F.
    Mechanistic investigation of host-microbe interactions in the human gut are hindered by difficulty of co-culturing microbes with intestinal epithelial cells. On one hand the gut bacteria are a mix of facultative, aerotolerant or obligate anaerobes, while the intestinal epithelium requires oxygen for growth and function. Thus, a coculture system that can recreate these contrasting oxygen requirements is critical step towards our understanding microbial-host interactions in the human gut. Here, we demonstrate Intestinal Organoid Physoxic Coculture (IOPC) system, a simple and cost-effective method for coculturing anaerobic intestinal bacteria with human intestinal organoids (HIOs). Using commensal anaerobes with varying degrees of oxygen tolerance, such as nano-aerobe Bacteroides thetaiotaomicron and strict anaerobe Blautia sp., we demonstrate that IOPC can successfully support 24–48 hours HIO-microbe coculture. The IOPC recapitulates the contrasting oxygen conditions across the intestinal epithelium seen in vivo. The IOPC cultured HIOs showed increased barrier integrity, and induced expression of immunomodulatory genes. A transcriptomic analysis suggests that HIOs from different donors show differences in the magnitude of their response to coculture with anaerobic bacteria. Thus, the IOPC system provides a robust coculture setup for investigating host-microbe interactions in complex, patient-derived intestinal tissues, that can facilitate the study of mechanisms underlying the role of the microbiome in health and disease.
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    Engineering bacterial thiosulfate and tetrathionate sensors for detecting gut inflammation
    (EMBO Press, 2017) Daeffler, Kristina N-M; Galley, Jeffrey D.; Sheth, Ravi U.; Ortiz-Velez, Laura C.; Bibb, Christopher O.; Shroyer, Noah F.; Britton, Robert A.; Tabor, Jeffrey J.
    There is a groundswell of interest in using genetically engineered sensor bacteria to study gut microbiota pathways, and diagnose or treat associated diseases. Here, we computationally identify the first biological thiosulfate sensor and an improved tetrathionate sensor, both two?component systems from marine Shewanella species, and validate them in laboratory Escherichiaﾠcoli. Then, we port these sensors into a gut?adapted probiotic E.ﾠcoli strain, and develop a method based upon oral gavage and flow cytometry of colon and fecal samples to demonstrate that colon inflammation (colitis) activates the thiosulfate sensor in mice harboring native gut microbiota. Our thiosulfate sensor may have applications in bacterial diagnostics or therapeutics. Finally, our approach can be replicated for a wide range of bacterial sensors and should thus enable a new class of minimally invasive studies of gut microbiota pathways.