Sweet lemon juice was fermented with Lactobacillus plantarum LS5 to produce a probiotic juice. The cell counts of the L. plantarum LS5 increased from 7.0 ± 0.1 to 8.63 ± 0.38 log CFU/mL during fermentation (37 °C for 48 h) (p < 0.05) and decreased from 8.63 ± 0.38 to 7.14 ± 0.21 log CFU/mL after storage (4 °C for 28 d). Antibacterial activity against S. Typhimurium and E. coli O157:H7 was observed in fermented sweet lemon juice. Immediately after fermentation, pH, lactic acid and antioxidant capacity of the samples increased, while glucose and fructose, total acidity, citric acid and phenolic decreased. During storage, phenolics, and antioxidant decreased in both fermented and non-fermented samples during storage. Moreover, the ascorbic acid was more stable in fermented juice compared to non-fermented juice. Fermentation of sweet lemon juice could improve the chemical as well as antibacterial properties of the juice.