Specific Aim 1. Test the hypothesis that maternal WD during gestation and lactation regulates offspring myeloid cell function through distinct metabolic and/or transcriptional mechanisms that accelerate NAFLD risk across the offspring lifespan. 1a) We will test if WD during gestation or lactation induces changes in number, activation state, or functional responses of fetal liver monocytes (Mo)/Mφ and hematopoietic stem and progenitor cells (HSPCs) or adult offspring liver Mφ and if this can be rescued by cross-fostering to a chow (CH)- fed dam. Liver histology and metabolic phenotyping will be used to evaluate severity of NAFLD and metabolic adaptations at 16 wks of age. 1b) We will profile metabolites and glycolytic/TCA cycle respiratory activity in offspring liver Mφ and BMDM to test for re-programming of immunometabolism. 1c) We will determine the impact of maternal WD exposure on transcriptional and epigenetic adaptations in isolated liver Mo/Mφ and BMDMs in early life and during adulthood. Specific Aim 2. Test the hypothesis that decreased AHR signaling provides a mechanistic link between maternal WD dysbiosis, Mφ metabolic reprogramming, and NAFLD risk. 2a) We will supplement WD-fed dams with an indole-based AHR agonist to determine if restoring AHR signaling protects against maternal WD-induced myeloid dysfunction in offspring. 2b) We will profile transcriptional and epigenetic adaptations in liver Mo/Mφ in WD-exposed offspring with myeloid deletion (KO) of AHR and assess for Mφ functional changes and NAFLD progression. Specific Aim 3. Test the hypothesis that dietary PQQ promotes gut microbial metabolism of indoles that preserve Mφ function in offspring exposed to maternal WD. 3a) We will test if PQQ-exposed microbes transferred to CH-fed GF dams during gestation or lactation increases bacterial production of indoles in offspring.