Abstract:The study utilized the principle of biofilm enrichment of microorganisms，with water insoluble dietary fiber（IDF）in celery as the carrier，Lactobacillus bulgaricus（Lb G302），L. plantarum（Lp G304），L.paracasei（Lcp G305），L. rhamnosus（Lr G306），Streptococcus thermophilus（St Q305）were strains，and MRS was the nutrient. In the self-designed enrichment culture device，celery IDF enriched multi-probiotics，and the biofilm culture containing celery IDF and multi-probiotic was formed. The viable count，flora structure，metabolite composition，tolerance to digestive fluids，and antioxidant activity of the biofilm culture were and studied. The results showed that after 7 days of enrichment culture at 37 ℃，the viable count could reach 7.5×1013 CFU/g；scanning electron microscopy showed that a thick biofilm was formed on the celery IDF；highthroughput sequencing analysis of Illumina NovaSeq at 0-7 d showed that Lactobacillus and Streptococcus inoculated were both detected. The results of 7-d metabolomics analysis showed that 1 398 metabolites were detected，among which the main functional substances were neurotransmitters，vitamins and coenzymes，and polypeptides. The scavenging rate of DPPH free radicals reached over 95%. After being treated with digestive fluids，the viable count was maintained at 1011 CFU/g.