The　aim　of　this　study　was　to　explore　the　alterations　in　physicochemical　characteristics,　bioactivity,　flavor　and　metabolic　profiles　of　mango　juice　fermented　by　Limosilactobacillus　reuteri　FJG2526　(L.　reuteri　FJG2526).　The　results　exhibited　that　L.　reuteri　FJG2526　had　strong　adaptability　in　mango　juice,　and　reduced　the　total　sugar,　polyphenolics　and　flavonoids　content　of　mango　juice.　L.　reuteri　FJG2526　fermentation　ameliorated　the　flavor　profiles　of　mango　juice,　particularly　promoted　the　production　of　acids,　alcohols,　and　esters.　Moreover,　107　metabolites　in　the　mango　juice　were　drastically　altered　after　48　h　L.　reuteri　FJG2526　fermentation　by　metabolomic　analysis,　including　73　remarkably　upregulated　metabolites　and　34　remarkably　downregulated　metabolites,　primarily　involving　amino　acid　metabolism.　In　addition,　L.　reuteri　FJG2526　fermentation　also　enhanced　the　ability　to　scavenge　DPPH　and　OH　free　radicals　of　mango　juice,　and　inhibited　lipase　and　alpha-glucosidase　activities.　This　study　offers　new　insights　into　the　mango　juice　fermentation　and　will　contribute　to　the　application　of　L.　reuteri　in　functional　juices.