Archaea might be correlated with periodontal diseases. The diversity of Archaea associated with periodontitis was limited. Almost all sequenced amplicons fell into the genus Methanobrevibacter of the Euryarcheota phylum. M. oralis-like species was the predominant but non-exclusive archaeon in the subgingival dental plaque of patients with periodontitis.

The colonoscopic features of colonic schistosomiasis are variable. Here we report a rare case of colonic schistosomiasis mimicking submucosal tumor. A 59-year-old man was admitted to our hospital complaining of intermittent melena and thinning stool. His symptoms had lasted for 5 years. He had lived in epidemic areas and was diagnosed with colonic schistosomiasis 20 years ago because of diarrhea, but he was cured and had regular follow-up for 3 years. The physical examination showed no positive signs such as abdominal wall varicosis and spider angioma, apart from his facial features indicating mild anemia. Laboratory data showed hemoglobin 68 g/L, stool examination was negative for ova, and there were normal levels of tumor markers such as alpha-fetoprotein, carcinoembryonic antigen and carbohydrate antigen 19 -9. The chest radiograph was normal. Abdominal computed tomography showed mild hepatic cirrhosis. The