Spice-Derived Bioactive Compounds Confer Colorectal Cancer Prevention via Modulation of Gut Microbiota

SIMPLE SUMMARY: Colorectal cancer (CRC) is a highly prevalent form of cancer, and represents a serious, global, health threat. Available therapeutic approaches have failed to provide control over the increasing prevalence and incidence of CRC. In this context, CRC prevention may provide a fruitful strategy. Edible plants have the potential to alter numerous molecular pathways, which may fight against the pathogenesis of CRC, and the gut microbiota could represent this link between dietary factors and CRC incidence. Spices and their active principles are reported to alter the balance of gut microbial species by increasing eubiotic and decreasing dysbiotic strains. The present study is designed to highlight the cancer prevention potential of spices while focusing mainly on gut microbial modulation. Although several spices and their active components have shown CRC-preventing properties via gut microbial modulation, the literature is still very limited, and expanding the literature going forward is essential before any conclusion can be drawn. ABSTRACT: Colorectal cancer (CRC) is the second most frequent cause of cancer-related mortality among all types of malignancies. Sedentary lifestyles, obesity, smoking, red and processed meat, low-fiber diets, inflammatory bowel disease, and gut dysbiosis are the most important risk factors associated with CRC pathogenesis. Alterations in gut microbiota are positively correlated with colorectal carcinogenesis, as these can dysregulate the immune response, alter the gut’s metabolic profile, modify the molecular processes in colonocytes, and initiate mutagenesis. Changes in the daily diet, and the addition of plant-based nutraceuticals, have the ability to modulate the composition and functionality of the gut microbiota, maintaining gut homeostasis and regulating host immune and inflammatory responses. Spices are one of the fundamental components of the human diet that are used for their bioactive properties (i.e., antimicrobial, antioxidant, and anti-inflammatory effects) and these exert beneficial effects on health, improving digestion and showing anti-inflammatory, immunomodulatory, and glucose- and cholesterol-lowering activities, as well as possessing properties that affect cognition and mood. The anti-inflammatory and immunomodulatory properties of spices could be useful in the prevention of various types of cancers that affect the digestive system. This review is designed to summarize the reciprocal interactions between dietary spices and the gut microbiota, and highlight the impact of dietary spices and their bioactive compounds on colorectal carcinogenesis by targeting the gut microbiota.