Linking Diet to Colorectal Cancer: The Emerging Role of MicroRNA in the Communication between Plant and Animal Kingdoms

Abstract

Environmental and lifestyle factors, including diet and nutritional habits have been strongly linked to colorectal cancer (CRC). Of note, unhealthy dietary habits leading to adiposity represent a main risk factor for CRC and are associated with a chronic low-grade inflammatory status. Inflammation is a hallmark of almost every type of cancer and can be modulated by several food compounds exhibiting either protective or promoting effects. However, in spite of an extensive research, the underlying mechanisms by which dietary patterns or bioactive food components may influence tumor onset and outcome have not been fully clarified yet. Growing evidence indicates that diet, combining beneficial substances and potentially harmful ingredients, has an impact on the expression of key regulators of gene expression such as the non-coding RNA (ncRNA). Since the expression of these molecules is deranged in chronic inflammation and cancer, modulating their expression may strongly influence the cancer phenotype and outcomes. In addition, the recently acquired knowledge on the existence of intricate inter-kingdom communication networks, is opening new avenues for a deeper understanding of the intimate relationships linking diet to CRC. In this novel scenario, diet-modulated ncRNA may represent key actors in the interaction between plant and animal kingdoms, capable of influencing disease onset and outcome. In this review, we will summarize the studies demonstrating a link between bioactive food components, including food-derived, microbiota-processed, secondary metabolites, and host ncRNA. We will focus on microRNA, highlighting how this plant/animal inter-kingdom cross-talk may have an impact on CRC establishment and progression.

Resistant Starches and Non-Communicable Disease: A Focus on Mediterranean Diet

“…Foods 2021, 10, x FOR PEER REVIEW 9 of 14 also regulated by epigenetic mechanisms, such as histone modifications or DNA methylation and the expression of miRNA. The randomized, controlled, crossover trial by Humphreys et al [101] was the first reported human study investigating the effects of RS on miRNA expression. The study highlighted how a diet rich in red meat could increase by approximately 30% miRNA expression from the miR-17-92 cluster, an oncogenic cluster overexpressed in colorectal cancer, while expression of five miRNAs from this cluster, namely miR-17, miR-19a, miR-19b, miR-20a and miR-92a were significantly reduced in subjects fed with RS (Figure 3).…”

The Crucial Roles of Diet, Microbiota, and Postbiotics in Colorectal Cancer

“…It is known that a diet rich in fruits, vegetables, and grains suppresses CRC, and not only high fiber content but also polyphenol content is effective in this regard [ 83 ]. Phytochemicals such as epigallocatechin-3-gallate, quercetin, ellagic acid, elicithins, proanthocyanidins, resveratrol, and curcumin can directly or indirectly affect the composition/metabolism of the gut microbiota and regulate gene expression epigenetically [ 86 ]. For example, the gut microbiota converts ellagitannins in foods such as pomegranates, strawberries, and nuts to a secondary polyphenol metabolite called urolithins.…”

“…Thioglucosidases derived from the microbiota can convert glucosinolates found in vegetables such as broccoli and cabbage to isothiocyanates, which have anti-carcinogenic properties and act as HDAC inhibitors. The gut microbiota can conjugate linoleic acid [ 86 ]. Conjugated linoleic acid is reported to have anti-carcinogenic properties [ 88 ].…”

The Impact of Diet on the Involvement of Non-Coding RNAs, Extracellular Vesicles, and Gut Microbiome-Virome in Colorectal Cancer Initiation and Progression

“…Chemo preventive effect is exhibited by some food components such as short chain fatty acids (SCFA), polyphenols, and omega-3 PUFA ( 127 ). Polyphenols are ubiquitous secondary metabolites, occurring in vegetables and fruits, beverages (wines, tea, coffee), and whole grain cereals.…”