Bacterial swimming biological fluids My project is to investigate the upstream swimming behavior of Escherichia coli in bile solutions from healthy individuals and patients to elucidate its role in cholecystitis, a gall bladder infection. By employing microfluidic channels filled with clinical bile samples, we measure E. coli swimming speed and orientation dynamics to uncover how the bacterium navigates from the gut to the gall bladder against bile flow. This study aims to establish a mechanistic link between E. coli’s upstream motility and cholecystitis pathogenesis, offering novel insights into infection pathways and potential therapeutic targets for gall bladder disease.