1The ability of Mycobacterium tuberculosis (Mtb) to persist inside host cells relies on 2 metabolic adaptation, like the accumulation of lipid bodies (LBs) in the so-called 3 foamy macrophages (FM). Indeed, FM are favorable to Mtb. The activation state of 4 macrophages is tightly associated to different metabolic pathways, such as lipid 5 metabolism, but whether differentiation towards FM differs between the 6 macrophage activation profiles remains unclear. Here, we aimed to elucidate if 7 distinct macrophage activation states exposed to a tuberculosis-associated 8 microenvironment can accumulate LBs, and its impact on the control of infection. 9We showed that signal transducer and activator of transcription 6 (STAT6) 10 activation in interleukin (IL)-4-activated human macrophages (M(IL-4)) prevents FM 11 formation induced by pleural effusion from patients with tuberculosis. In these cells, 12 LBs are disrupted by lipolysis, and the released fatty acids enter the -oxidation 13 (FAO) pathway fueling the generation of ATP in mitochondria. We demonstrated 14 that inhibition of the lipolytic activity or of the FAO drives M(IL-4) macrophages into 15 FM. Also, exhibiting a predominant FAO metabolism, mouse alveolar macrophages 16 are less prone to become FM compared to bone marrow derived-macrophages. 17 Upon Mtb infection, M(IL-4) macrophages are metabolically re-programmed 18 towards the aerobic glycolytic pathway and evolve towards a foamy phenotype, 19which could be prevented by FAO activation or inhibition of the hypoxia-inducible 20 factor 1-alpha (HIF-1α)-induced glycolytic pathway. In conclusion, our results 21 demonstrate a role for STAT6-driven FAO in preventing FM differentiation, and 22