Figure 1.

Impact of dietary components on Treg development. Dietary components have varying effect on Treg development, with dietary fats inducing Treg by modulating metabolic activity or through the activation of nuclear receptors (NRs) such as PPARδ. Dietary protein generally support Treg development, with L-citrulline enhancing the histone deacetylase (HDAC) Sirt1 to promote Treg development. Dietary carbohydrates, including feruloylated oligosaccharides and glucose act on conventional dendritic cell (cDC) and CD103⁺ DC, boosting their production TGF-β and retinoic acid (RA), respectively, to promote Treg. Vitamin (Vit) A is a substrate for RA production required for Treg induction while vitamin B7 and D finetune mTOR-related metabolic signals or bind to NRs to support Treg induction. Dietary trace elements like selenium (Se) and zinc (Zn) are supportive toward Treg development with unknown mechanisms. The food additives TiO₂ and salt, and the contaminant biphenol A (BPA) exhibit mixed/complex regulatory patterns toward Treg development while pesticides like chlorpyrifos suppressed Treg development. Dietary components promoting Treg development are colored in green, the ones impeding in blue, and the ones with mixed effect in yellow.