Si-Yu Chen, Gui-Rong Liu, Ji-Heng Wu, Yi-Yue Jia, Ya-Zhuo Huang, Huidi Liu, Yu-Xuan Cai, Shu-Lin Liu, Zheng Liu, Xia Li, Zhi-Lin Yue, Tammy Lu, Yong-Guo Li, Chen Haoting, Jia-Jing Li, Zhan-Yi Zhao, Xiaoqin Mu, Dan-Dan Zhao, Bing-Qing Yao, Pei-Qiang Liang, Yu-Jie Zhou, Xue Peng, Peng-Ge Wang, Le Tang, and Xin-Yuan Yuan
// Yu-Jie Zhou 1, 2 , Dan-Dan Zhao 1, 2 , Huidi Liu 1, 2 , Hao-Ting Chen 1, 2 , Jia-Jing Li 1, 2 , Xiao-Qin Mu 1, 2 , Zheng Liu 3 , Xia Li 1, 2 , Le Tang 1, 2, 6 , Zhan-Yi Zhao 1, 2 , Ji-Heng Wu 1, 2 , Yu-Xuan Cai 1, 2 , Ya-Zhuo Huang 1, 2 , Peng-Ge Wang 1, 2 , Yi-Yue Jia 1, 2 , Pei-Qiang Liang 1, 2 , Xue Peng 1, 2 , Si-Yu Chen 1, 2 , Zhi-Lin Yue 1, 2 , Xin-Yuan Yuan 1, 2, 7 , Tammy Lu 1, 2, 8 , Bing-Qing Yao 1, 2 , Yong-Guo Li 4 , Gui-Rong Liu 1, 2 and Shu-Lin Liu 1, 2, 4, 5 1 Systemomics Center, College of Pharmacy, and Genomics Research Center, State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Harbin Medical University, Harbin, China 2 HMU-UCFM Centre for Infection and Genomics, Harbin Medical University, Harbin, China 3 Colorectal Surgery Department, Cancer Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China 4 Department of Infectious Diseases, The First Affiliated Hospital, Harbin Medical University, Harbin, China 5 Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, Canada 6 Current affiliation: Department of Ecosystems and Public Health, University of Calgary, Calgary, Canada 7 Current affiliation: Life Sciences, Queen’s University, Kingston, Canada 8 Current affiliation: Biomedical Science, University of Calgary, Calgary, Canada Correspondence to: Shu-Lin Liu, email: slliu@hrbmu.edu.cn Keywords: cancer, malignancy killer, Actinobacteria, gut microbiota, leukemia Received: December 12, 2016 Accepted: April 02, 2017 Published: April 21, 2017 ABSTRACT Cancer as a large group of complex diseases is believed to result from the interactions of numerous genetic and environmental factors but may develop in people without any known genetic or environmental risks, suggesting the existence of other powerful factors to influence the carcinogenesis process. Much attention has been focused recently on particular members of the intestinal microbiota for their potential roles in promoting carcinogenesis. Here we report the identification and characterization of intestinal bacteria that exhibited potent anti-malignancy activities on a broad range of solid cancers and leukemia. We collected fecal specimens from healthy individuals of different age groups (preschool children and university students), inspected their effects on cancer cells, and obtained bacteria with potent anti-malignancy activities. The bacteria mostly belonged to Actinobacteria but also included lineages of other phyla such as Proteobacteria and Firmicutes. In animal cancer models, sterile culture supernatant from the bacteria highly effectively inhibited tumor growth. Remarkably, intra-tumor administration of the bacterial products prevented metastasis and even cleared cancer cells at remote locations from the tumor site. This work demonstrates the prevalent existence of potent malignancy-killers in the human intestinal microbiota, which may routinely clear malignant cells from the body before they form cancers.