  The IceCube Neutrino Detector observes tens of thousands of atmospheric
neutrinos every year with its low energy extension DeepCore, covering the
neutrino energy range from GeV to TeV. These neutrinos can be used to study
particle interactions in conditions that are inaccessible to current
accelerator-based experiments. Here, we present constraints concerning the
production of light and strange mesons in atmospheric particle cascades using a
dedicated analysis based on the shape of the neutrino spectrum in zenith and
energy. We report the first measurement of the atmospheric K/Pi-ratio in a
constrained energy range exclusively from neutrino observations.
