Disclosed in the present disclosure are a composition for preventing hair loss or promoting hair growth, which contains lactic acid bacteria-derived extracellular vesicles as an active ingredient, and a method for preparing the lactic acid bacteria-derived extracellular vesicles. The composition is effective in preventing loss of hair from the scalp or thinning of hair. Also, the composition is effective in sprouting new hair, promoting the hair sprouting, promoting delay of transition from anagen to catagen in the hair growth cycle, and promoting healthy growth of existing hair.本說明書揭露一種防止掉髮或促進生髮之組成物，其含有作為活性成分之由乳酸菌衍生之胞外囊泡及一種製備由乳酸菌衍生之胞外囊泡之方法。該組成物能有效防止頭皮掉髮或頭髮稀疏。且該組成物能有效使新髮萌發、促進毛髮萌發、促進生髮周期中生長期延遲過渡至退化期及促進現有頭髮之健康生長。
