E. Abstract (Molecular Mechanisms Core) Nutrition and Obesity Research Centers (NORCS) serve as focal points for biomedical research targeting nutritionally responsive chronic diseases, arguably the greatest public health challenge of the 21st century. In this context, the PBRC NORC has chosen the theme of ‘Nutrition, Obesity, and Metabolic Health through the Lifespan’, with emphasis on three research focus areas: (1) Maternal/Infant nutritional status; (2) Pediatric and adulthood obesity and (3) Nutritional status at older age to preserve physical and cognitive functionality. Nutrition and obesity are significant modulators of whole-body physiology, as they can impinge upon cellular signaling pathways in essentially every cell type and tissue of the body. Both short-term and chronic exposure, to e.g. to nutrients, or to metabolic state, can produce specific cellular or physiological responses. Understanding the mechanisms affected by nutrition, obesity, or both, and the resulting consequences for metabolic health, represents the critical foundation for the development of treatments to improve public health, and for the invention of new strategies for prevention of chronic disease. The Molecular Mechanisms Core provides scientific, technological, and bioinformatics assistance for investigating the molecular etiology elicited by nutrition, obesity, or both. The majority of Core technologies are centered on capturing changes in expression of genes and gene products, both crucial readouts of acute and chronic exposure effects. The Core offers functional genomics and systems biology tools for transcriptome profiling, methods for expression measurements on the tissue and cellular level, and powerful quantitative bioimaging technology to localize expression in cells or tissues with high resolution. Expression measurements are complemented by epigenomics tools to investigate the upstream regulatory mechanisms, and by procedures to monitor cellular bioenergetics, a crucial readout of cellular function that affects metabolic health. As a new development, the Core provides both molecular and imaging techniques towards the analysis of gut microbiome composition, an important modulator of metabolic health. The Molecular Mechanism Core provides service, method development, consultation, enrichment, and community outreach to a large user base, and consistently supports NIH-funded research projects. By offering shared technologies that are typically too complex and too expensive for research laboratories, and by serving as an intellectual resource, the Core removes critical barriers to progress in the field for many NORC members and investigators in Louisiana, and assists them with adapting new technology into their research programs.