Immune, inflammatory, and metal biomarker profiles in chronic respiratory diseases receiving oligo-fucoidan under ambient PM₂.₅ exposure.

Industrial zones are prevalent in central Taiwan, with major sources of ambient air pollution including large thermal power plants and steel manufacturing facilities. Fine particulate matter (PM₂.₅) is a critical component of air pollution and has been implicated in the development and progression of chronic respiratory diseases (CRDs), primarily through pathways involving immune dysregulation and persistent low-grade inflammation. Oligo-fucoidan (OF), a low–molecular-weight derivative of fucoidan, has been reported to exert immunomodulatory and anti-inflammatory effects in experimental and preclinical studies. However, clinical evidence regarding its potential role in air pollution–associated respiratory conditions remains limited. This exploratory, non-randomized, open-label study aimed to descriptively evaluate changes in immune and inflammatory parameters among patients with air pollution–associated chronic pulmonary diseases residing in central Taiwan. A total of 46 participants received OF supplementation (2.2 g daily) for 12 weeks in addition to standard care. Blood samples were collected at baseline and at weeks 4, 8, and 12 to assess biochemical indices, lymphocyte subsets, inflammatory cytokines, and serum heavy metal concentrations. Ambient PM₂.₅ data during the study period were obtained from nearby governmental air quality monitoring stations. Ambient PM₂.₅ concentrations during the study period were within a relatively low range (11.1 ± 4.0 to 14.7 ± 10.3 µg/m³). Over the 12-week supplementation period, descriptive variations were observed in several immune and inflammatory markers, including white blood cell count, C-reactive protein, ferritin levels, lymphocyte subset distributions, and selected cytokines. Serum mercury concentrations demonstrated a positive association with ambient PM₂.₅ levels. Among the measured cytokines, IL-8 values at later time points were lower than at baseline; these changes are presented descriptively and should be interpreted cautiously given the exploratory, single-arm nature of the study. This exploratory study provides a descriptive characterization of immune, inflammatory, and heavy metal–related parameters in patients with air pollution–associated chronic pulmonary diseases receiving oligo-fucoidan as an adjunct to standard therapy. While causal relationships and statistically confirmed longitudinal effects cannot be established, these preliminary observations may inform the design of future controlled trials and mechanistic investigations in the context of environmental respiratory health.