Differing from commercially synthetic or natural weight-reducing drugs does not provide obvious slimming effect, a DOWLactobacillus-fermented composition having functionality to inhibit body fat formation is proposed in the present invention. After completing a fermentation process of a mixing substrate consisting of a first ingredient ofHouttuyniacordata, a second constituting ingredient ofCamellia sinensis(L.) Kuntze, and a third constituting ingredient of deep ocean water (DOW) by using aLactobacillus plantarum, the said composition having functionality to inhibit body fat formation is then produced and obtained. Moreover, a variety of experimental data obtained from animal experiments have proved that a 60-kilogram adult dosage of 50 mL/day is helpful to reduce weight increment, food utilization rate and body fat as well as inhibit adipocyte differentiation and stimulate lipolysis.不同於市售合成減肥藥多具副作用以及天然性的減肥健康食品多不具實際減肥功效,本發明係利用胚芽乳桿菌(Lactobacillus plantarum)發酵由魚腥草、綠茶、深層海水、與液態培養基之一混合基質,進而獲得一深層海水乳酸菌發酵產物。本發明係以此深層海水乳酸菌發酵產物可以作為用以減少體脂肪形成之組合物;並且,經由動物實驗證實,60 kg 成人之每日服用量至少為50 mL的該組合物係顯示出減少體重增加量、減少食物利用率、降低體脂肪量、抑制脂肪細胞分化、以及促進脂解作用之功效。S1~S4‧‧‧方法步驟S51‧‧‧方法步驟