TNF and serum lipopolysaccharide activity: Our findings regarding the modulation of pro-inflammatory cytokines (IL-6 and TNF-α) in zebrafish fed an HFD are consistent with the concept of metabolic endotoxemia discussed by Rosendo-Silva et al. (2023), wherein LPS from gut bacteria translocates into the bloodstream, activates Toll-like receptors, and induces chronic low-grade inflammation [28].