Therefore, we proposed that the oral administration of PELNs enhanced the abundance of Lactobacillus reuteri and increased the levels of indole derivatives, leading to the activation of AhR in conventional CD4+ T cells, subsequent downregulation of Zbtb7b, and increased differentiation of DP CD4+CD8+ T cells, ultimately mitigating colitis in mice. The gene discussed is CD8A; the disease is colitis.