<b>Supplemental Material: Dietary Influence on Lung Injury and Immune Modulation in Cadmium-Exposed Mice</b>

Cadmium (Cd), a toxic heavy metal found in air pollution, poses serious risks to lung health due to its efficient pulmonary absorption and prolonged biological half-life. This study examines how time-restricted feeding (TRF) and intermittent fasting (IF) influence Cd-induced lung injury and immune responses in mice. Adult male C57BL/6 mice were pre-acclimated to TRF or IF regimens for three weeks, then exposed intratracheally to cadmium chloride (CdCl₂, 0.5 mg/kg). Lung function was assessed via flexi-Vent, inflammation was measured in bronchoalveolar lavage (BAL) fluid, and immune profiles of the spleen and mediastinal lymph nodes were analyzed 14 days post-exposure. Cd exposure increased immune cell infiltration in BAL fluid. While TRF mice exhibited mild increases in cytokine levels, IF mice showed significantly higher levels of inflammatory cytokines. Surprisingly, lung histology revealed more severe inflammation in TRF mice, whereas lung mechanics were more impaired in IF mice, suggesting distinct responses to Cd. Immune profiling showed that IF reduced activated and effector T-cell numbers in the spleen while increasing their presence in mediastinal lymph nodes, indicating a potential shift in immune localization toward draining lymphoid tissues during Cd-induced inflammation. These results suggest that dietary regimens may modulate immune homeostasis and lung injury during Cd exposure under the specific conditions tested. The findings highlight the potential importance of considering feeding patterns in studies of environmental toxicants and suggest that dietary interventions could influence susceptibility and immune responses to lung injury, warranting further investigation.