PROJECT SUMMARY
This K08 proposal outlines the plan for Kale Bongers, M.D. Ph.D.’s to complete training toward his long-term
goal of improving our understanding of post-sepsis muscle atrophy and weakness through investigation of the
microbiome. Dr. Bongers is a physician-scientist in Pulmonary and Critical Care Medicine at the University of
Michigan with an established record of success in skeletal muscle biology and microbiome studies. This
proposal builds on Dr. Bongers’ previously acquired skillset in skeletal muscle biology, critical illness
pathophysiology, and microbial ecology with new training in metabolomics and metagenomics. These skills will
be integrated to improve our understanding of the role of the gut microbiome in mediating skeletal muscle
atrophy after sepsis. This research will be conducted under the guidance of mentor Robert Dickson, M.D., co-
mentor Kathleen Stringer, Pharm.D., and an advisory board of renowned investigators with experience in
metabolomics, microbial ecology, microbiome studies, skeletal muscle in critical illness, and sepsis
pathophysiology. The five-year plan includes intensive mentorship, formal didactic coursework, professional
development, and increasingly independent research, with milestones to encourage productive research output
and transition to independence. Sepsis is a common and deadly condition of organ dysfunction and immune
dysregulation secondary to infection that often leaves its survivors severely debilitated due to muscle atrophy.
Studies have suggested that the gut microbiome plays a critical role in the regulation of skeletal muscle size
and strength, but to date no study has evaluated the role of the gut microbiome in the pathogenesis of post-
sepsis skeletal muscle atrophy. This proposal tests the hypothesis that the gut microbiome plays a critical role
in post-sepsis skeletal muscle atrophy via two specific Aims. Aim 1 will identify the key bacterial taxa that
contribute to or prevent muscle atrophy in multiple models of murine sepsis, while Aim 2 will identify key
bacterially-derived metabolites that mediate these changes in muscle. To accomplish these Aims, Dr. Bongers
will leverage both in vivo and in vitro models of skeletal muscle with cutting-edge techniques in metabolomics
and metagenomics to identify and mechanistically interrogate how gut bacteria influence skeletal muscle size
and function during sepsis. This will lay crucial groundwork for future R01 proposals to 1) determine whether
supplementation of key bacteria or key bacterially-derived metabolites can prevent skeletal muscle atrophy and
2) translate these findings to humans using morphomics and pre-existing bacterial swabs. In addition to
building a strong line of research to understand the role of the microbiome in muscle atrophy, this proposal will
provide Dr. Bongers with new research skills applicable to microbiome and metabolomics research. This K08
award will enable Dr. Bongers to establish himself as an independent physician-scientist and rising leader in
this important field.