Our research focuses on understanding the role of cofactors, such as vitamin B₁₂, in shaping the composition of the gut microbiome. Vitamin B₁₂ is an essential cofactor for many gut bacteria, yet a significant proportion of these bacteria are unable to synthesize it. Instead, they rely entirely on transport from their environment to meet their needs. We will concentrate our efforts on understanding how gut bacteria acquire and utilize vitamin B₁₂. Specifically, we will elucidate the mechanisms by which these bacteria transport and selectively use vitamin B₁₂. To achieve this, our laboratory will use a variety of techniques, including spectroscopy (UV-visible, fluorescence, EPR), membrane protein biochemistry, and structural methods (X-ray crystallography, cryo-EM), to gain mechanistic and structural insights into cobamide selectivity and trafficking in gut bacteria.