The present invention provides an active substance ofLactic Acid Bacteria, a composition comprising thereof and its use for promoting longevity, especially, for increasing expression of gene Cisd2, reducing damage of mitochondria, delaying ageing phenomenon as nerve degeneration and muscle atrophy etc..本發明提供一種乳酸菌之活性物質、含其之組合物及其促進長壽之用途,特別用於增加Cisd2基因表現量、降低粒線體破損、延緩神經退化與肌肉萎縮等老化現象。