Cancer is one of the world’s leading severe illnesses. Cancer incidence is expected to rise further over the globe due to an aging population and the presence of various modifiable risk factors. During the past decades, cancer treatment remained broadly similar, with chemotherapy and/or radiation in conjunction with surgery maintaining the conventional treatments; however, innovative medicines are gradually replacing or complementing the old ones. Furthermore, there are no clear standards for dietary recommendations on the type of nutrition that might significantly influence cancer incidence. Various forms of fasting have been linked to a broad spectrum of favorable benefits in cancer prevention and treatment effectiveness. Calorie restriction, intermittent fasting, fasting-mimicking diets, and dietary restriction without calorie restriction are examples of fasting. These types of diets have proposed to be utilized to prevent and treat cancer. On the other hand, previous studies investigated the anticancer effects of probiotics. Experimentally altered gut microbiota may, in fact, influence carcinogenesis and tumor formation through immunologic pathways. We provide findings on dietary restriction and probiotics, as well as their roles in producing cellular defense and chemotherapy resistance.