Lactobacillus fermentum PL9988 was isolated from an elderly person over 80 years of age living in a Korean longevity village. Results from a previous study showed various characteristics of L. fermentum PL9988 as a probiotic, including resistance to acid and bile acid, immune-enhancing activity, adhesiveness to the intestinal cell line Caco-2, inhibition of various intestinal pathogens, antioxidation activity, and susceptibility to antimicrobials. In this study, the binding activity of L. fermentum PL9988 to the intestine was confirmed in another human intestinal cell line, HT-29, and mouse intestinal cells. The anti-inflammatory activity of L. fermentum PL9988 was examined via both in vitro and in vivo experiments. Lactobacillus fermentum PL9988 increased the amount of IL-10 and decreased the amount of TNF-α in HT-29 cells treated with LPS. Similar results were observed in an in vivo experiment with BALB/c mice fed L. fermentum PL9988. Thus, results from the previous study and this study demonstrate the beneficial characteristics of L. fermentum PL9988 as a good probiotic with anti-inflammatory, antioxidative, and immune-enhancing activities in addition to improving intestinal health.