Platycodonis Radix, a well-known edible and medicinal plant, has been used to create functional meals or dietary supplements. The primary bioactive effects constituents in it, known as platycosides, are pentacyclic triterpenoid saponins of the oleanane type. Compared to glycosylated platycosides, deglycosylated platycosides have stronger bioactivities. Herein, Lactobacillus plantarum M3, which was isolated from Platycodonis Radix pickles, was used to ferment the total platycosides and the products' effect on fat accumulation was evaluated in HepG2 cells. We demonstrated this strain can biotansformate glycosylated saponins into platycoside D₃, deapiosylated platycoside D₃ and deapiosylated platycoside D. The products have the ability to significantly reduce the accumulation of intracellular lipids and the contents of cholesterol (TC) and triglyceride (TG) in HepG2 cells. Additionally, deapiosylated platycosides had a stronger anti-inflammatory impact than their precursor glycosylated counterparts. In conclusion, deglycosylated platycosides have a potential lipid-lowering capacity and can be used as functional food additives.