Early-onset Palmijihwang-hwan treatment modulates phospholipid metabolism and gut microbiota for healthy aging: reducing adipose inflammation and oxidative stress

Aging is characterized by progressive physiological decline and increased vulnerability to metabolic and inflammatory disturbances. Palmijihwang-hwan (PM), a traditional East Asian herbal formula, has been used empirically for age-related complaints, but its mechanistic basis remains unclear. Here, we evaluated the effects of early-onset PM administration (starting at 2 months of age) on longevity-related phenotypes and metabolic regulation. PM significantly prolonged lifespan in Caenorhabditis elegans and improved survival in ICR mice without evident toxicity. Preventive PM administration reduced epididymal white adipose tissue (eWAT) mass and circulating insulin/adipokine levels. Lipidomic analysis showed a shift from lysophospholipids toward phospholipids, accompanied by downregulation of PLA2G7, indicating attenuation of adipose inflammation. PM also reshaped the gut microbiota, decreasing inflammation-associated taxa such as Oscillibacter valericigenes, and lowered adipose IL-6 and TNF-α expression. Collectively, these findings indicate that preventive early-onset PM administration modulates the gut microbial composition, counteracting the age-related enrichment of inflammation-related bacteria.