Akkermansia muciniphilais a promising probiotic in the gut. This study aimed to determine the presence and abundance ofAkkermansiain patients with inflammatory bowel disease (IBD) who underwent washed microbiota transplantation (WMT) in order to elucidate the relationship between its level and patients' clinical data and outcomes. A cohort of Chinese volunteers including 80 healthy controls (HC), 43 patients with ulcerative colitis (UC), and 57 patients with Crohn's disease (CD) were recruited. Akkermansia presented a low colonization rate of 48.8% and a relative abundance of 0.07% in a healthy Chinese population. Compared with HC, significantly lower colonization and abundance ofAkkermansiawere found in UC and CD (p < 0.01,p < 0.001, respectively). The combination ofAkkermansiaand twelve other gut commensal bacteria significantly enriched in healthy individuals could be conductive to discriminate IBD from HC. Co-occurrence ofAkkermansia-Faecalibacterium prausnitziiwas at a lower level in IBD. Patients' age could affect the abundance ofAkkermansiain CD. After WMT, 53.7% of patients achieved clinical response, and the colonization rate of Akkermansia increased significantly than that pre-WMT (p < 0.01). There was a positive correlation between patients and donors in the abundance of Akkermansiaafter WMT. Different from Europeans, the healthy Chinese population is characterized by a low presence of intestinalAkkermansia. Compared with healthy people, its colonization and abundance in IBD decreased more significantly. The efficacy of WMT for IBD was closely correlated withAkkermansia., pooled registered trials, NCT01790061, NCT01793831. Registered February 13, 2013, 18 February 2013.