To provide a skin care composition having effects of anti-inflammation, moisturization, and whitening of skin yellowing.SOLUTION: The present invention discloses application of a fermentation product in preparing reagents for anti-inflammation, moisturization, or whitening of skin yellowing, the fermentation product is prepared from thermus thermophilus and yeast through fermentation co-culture, a thermus thermophilus and yeast co-fermentation method comprising the following steps: firstly, carrying out bacterium increase fermentation once or multiple times on yeast at low temperature under acidic condition after a logarithmic phase, increasing the temperature of a fermentation liquid to a high temperature from a low temperature, adding thermus thermophilus, and carrying out secondary fermentation under alkaline condition. The method includes the steps of: (1) performing one-time or multi-time fermentation to saccharomyces cerevisiae at low temperature under acidic condition, thus reproducing the yeast； and (2) when the yeast is in a later period of a logarithmic phase, increasing the temperature, inoculating the thermus thermophilus, and performing second fermentation under alkaline condition, thereby producing a fermentation product.SELECTED DRAWING: Figure 1【課題】消炎、保湿および皮膚の黄み消去における効果を有するスキンケア組成物の提供。【解決手段】好熱性細菌および酵母菌の共生発酵培養による発酵生成物の消炎、皮膚保湿または皮膚の黄色消去の試薬の製造における用途であって、好熱性細菌および酵母の共生発酵方法は、まず、酵母の低温、酸性条件における液体に対して１回または複数回の増殖発酵を行い、対数増殖期にさせた後、発酵液の温度を低温から高温に昇温させた後、サーマス・サーモフィラスを添加して二次発酵を行うことを含み、発酵条件はアルカリ条件である。サッカロマイセス・セレビシエを低温、酸性条件において１回または複数回発酵させ、酵母菌を増殖させるステップ（１）と、酵母菌が後期対数増殖期になってから温度を昇温させ、サーマス・サーモフィラスを接種し、アルカリ条件において第２回発酵を行い、発酵生成物を得るステップ（２）と、を含む。【選択図】図１
