Vol.:(0123456789) 1 3 Journal of Cancer Research and Clinical Oncology https://doi.org/10.1007/s00432-018-2816-0 REVIEW – CANCER RESEARCH Microbiota in cancer development and treatment Muhammad Hassan Raza 1  · Kamni Gul 1  · Abida Arshad 2  · Naveeda Riaz 1  · Usman Waheed 3  · Abdul Rauf 4  · Fahad Aldakheel 5  · Shatha Alduraywish 6  · Maqbool Ur Rehman 1  · Muhammad Abdullah 1  · Muhammad Arshad 1 Received: 11 August 2018 / Accepted: 5 December 2018 © Springer-Verlag GmbH Germany, part of Springer Nature 2018 Abstract Purpose Human microbiota comprises of a variety of organisms ranging from bacterial species to viruses, fungi, and protozoa which are present on the epidermal and mucosal barriers of the body. It plays a key role in health and survival of the host by regulation of the systemic functions. Its apparent functions in modulation of the host immune system, inducing carcinogenesis and regulation of the response to the cancer therapy through a variety of mechanisms such as bacterial dysbiosis, production of genotoxins, pathobionts, and disruption of the host metabolism are increasingly becoming evident. Methods Diferent electronic databases such as PubMed, Google Scholar, and Web of Science were searched for relevant literature which has been reviewed in this article. Results Characterization of the microbiome particularly gut microbiota, understanding of the host–microbiota interactions, and its potential for therapeutic exploitation are necessary for the development of novel anticancer therapeutic strategies with better efcacy and lowered of-target side efects. Conclusion In this review, the role of microbiota is explained in carcinogenesis, mechanisms of microbiota-mediated car- cinogenesis, and role of gut microbiota in modulation of cancer therapy. Keywords Microbiome · Gut microbiota · Carcinogenesis · Cancer therapy Introduction The human microbiota comprises of several types of over one hundred trillion organisms including bacteria, viruses, fungi, and protozoans that are primarily inhabited on the epithelial surface of human body. Human gut is the major contributor to the human microbiome. It has largest num- ber of bacteria and is very diverse with respect to the other areas of human body. It provides nutrient rich and protective conditions to resident microbiota. Whilst, the gut microbiota benefts human body by playing a key role in the produc- tion of short chain fatty acids (SCFAs) from dietary fber, synthesis of vitamin B and vitamin K, metabolism of several compounds such as sterols and xenobiotics, and regulation of immune functions (Clarke et al. 2014; Quigley 2013; Shen and Wong 2016). However, its role in several diseases such as cancer, liver disease, obesity, and neuropsychiat- ric disorders has also been reported (Boulangé et al. 2016; Minemura and Shimizu 2015; Wang and Kasper 2014; Zit- vogel et al. 2015). Host immune system tolerates the human microbiota while safeguarding against the invading patho- genic microbes (Zitvogel et al. 2015). Particularly, it plays a key role in cancer initiation, development, and its response to cancer therapy (Fig. 1; Tables 1, 2). Living organisms which are raised in controlled environ- ment that prevents the growth of microbiota in them; also known as germ free organisms, have several poorly devel- oped physiological conditions such as innate immunity * Muhammad Arshad m.arshad@iiu.edu.pk 1 Department of Bioinformatics and Biotechnology, International Islamic University, Islamabad, Pakistan 2 Department of Biology, PMAS-Arid Agriculture University, Rawalpindi, Pakistan 3 Department of Pathology and Blood Bank, Shaheed Zulfqar Ali Bhutto Medical University, Islamabad, Pakistan 4 Department of Zoology, Azad Jammu and Kashmir University, Muzafarabad, Pakistan 5 Department of Clinical Laboratory Medicine, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia 6 Department of Family and Community Medicine, College of Medicine, King Saud University, Riyadh, Saudi Arabia