Tuberculosis and Cellular Metabolism: Insights into the Crosstalk Between Macrophage Immunometabolism and Muscle Dysregulation.

Tuberculosis (TB) remains a leading cause of death from a single infectious agent, and its outcome is shaped not only by Mycobacterium tuberculosis (Mtb) itself, but also by the host's metabolic state. This review synthesises current understanding of how Mtb reprograms macrophage immunometabolism and how this reprogramming propagates to a systemic level, culminating in skeletal muscle dysregulation and TB-associated cachexia. We describe the molecular mechanisms by which Mtb subverts phagosomal maturation, the glycolytic (Warburg-like) switch governed by HIF-1α and accumulation of immunomodulatory tricarboxylic acid cycle intermediates, and the M1/M2 polarisation balance that dictates bacterial containment versus persistence. We then trace the cytokine- and metabolite-mediated circuits (TNF-α, IL-6, IL-1β, lactate, ketone bodies, free fatty acids) that link infected macrophages to ubiquitin-proteasome and autophagy-lysosome-driven muscle proteolysis, mitochondrial dysfunction and oxidative stress. Building on these mechanisms, we propose an immunometabolic and muscle-derived biomarker framework that, although still requiring clinical validation, may offer value for diagnosis, host-response stratification and treatment monitoring, and we discuss host-directed therapeutic strategies that target macrophage metabolism and muscle preservation. By integrating immunity, metabolism and systemic pathology at the molecular level, this work highlights translational opportunities relevant to the host immunity, diagnosis and treatment of tuberculosis.