The invention relates to a novel strain, Lactobacillus fermentum strain, and a use thereof. Specifically, novel Lactobacillus fermentum PL9988, novel Lactobacillus fermentum PL9037, novel Lactobacillus fermentum PL9038, novel Lactobacillus fermentum PL9039 and novel Lactobacillus fermentum PL9040 strains, isolated from adults in a longevity village, and culture fluids thereof: have no antibiotic resistance transfer; have excellent intestinal cell adhesiveness, acid resistance and bile resistance; inhibit harmful pathogenic organisms in intestines; and have an immunity-enhancing effect, an endotoxin shock suppression effect and an antioxidant effect. In particular, Lactobacillus fermentum PL9988 strain significantly satisfies all of the above-mentioned conditions as a probiotic, and thus can be effectively used as a probiotic for intestinal health and defecation improvement and enhancement, or as a health food.