I request a supplement to my R35 MIRA award to help acquire the laser source for a Stimulated Raman Microscope to aid my lab’s research on developing new microscopy tools for human gut microbiome research. In my original MIRA application, Developing Next-Generation Physiology approaches for human gut microbiome research (award 1R35GM147166-01), I described the strong but currently underutilized potential of Raman microspectroscopy (Raman) for human gut microbiome research. Specifically, I addressed how Spontaneous Raman microscopy will be used in research directions 2 and 3, which will combine stable isotope probing and Raman to probe microbial in situ function (direction 2) and correlate Raman with other microscopic techniques to gain a more holistic understanding of gut microbes (direction 3). Stimulated Raman spectroscopy offers 1,000-1,000,000 faster acquisition rates than Spontaneous Raman spectroscopy, but until recently was not commercially available; this changed when Leica brought the first Spontaneous Raman microscope to market. The capabilities of this instrument will allow spectral acquisition to be increased by a factor of 1,000, which will enable colonoscopy and other human gut microbiome samples to be chemically mapped at subcellular spatial resolution within minutes. In addition, it will allow my lab to expand our research to visualize microbial cell identity and anabolic activity using vibrational probes, which is not possible using currently Spontaneous Raman technology and thus was not included in my original MIRA application. If awarded, this instrument will become the 3rd Stimulated Raman microscope at any university in the nation.