The main properties of biogas as radioprotector are: anti-apoptosis, antioxidants, and anti-inflammation and radioresistance reductions. There are several reports indicating gas producing bacteria in human bodies act as anti-cancer agents [37–39]. For example Murata et al. showed H2S, a common metabolite of anaerobic oral bacteria, is an anticancer compound that may contribute to the low incidence of oral cancer [40]. Therefore these microorganisms can act as radioprotectors and also as primary and secondary cancer prevention agents. Targeting these agents into normal tissues during radiotherapy may enhance the outcome of treatment and lower normal tissue damages. One of the main issues regarding this hypothesis is the biosafety of gas producing microorganisms. It is should emphasized that there are many microorganisms such that are available in the human body, but it is important to ensure that those microorganisms not contain pathogens that can damage human tissues. Pretreatment of these living systems with technological techniques is required to have lowest pathology during and after consumption or injection of these organisms.