Dietary Tomato Powder Inhibits High-Fat Diet-Promoted Hepatocellular Carcinoma with Alteration of Gut Microbiota in Mice Lacking Carotenoid Cleavage Enzymes

Lycopene Ameliorated DSS-Induced Colitis by Improving Epithelial Barrier Functions and Inhibiting the Escherichia coli Adhesion in Mice

Adherent-invasive Escherichia coli plays an important role in the pathogenesis of inflammatory bowel disease. Blocking the adhesion of E. coli to intestinal epithelial cells appears to be useful for attenuating inflammatory bowel disease. Lycopene has been reported to have anti-inflammatory and antimicrobial activities. The aim of this study was to test the intervention effect of lycopene on colitis in mice and to investigate the possible mechanism through which lycopene affects the adhesion of E. coli to intestinal epithelial cells. Lycopene (12 mg/kg BW) attenuated dextran sulfate sodium (DSS)-induced colitis, decreased the proportion of E. coli, and activated the NLR family pyrin domain containing 12 and inactivated nuclear factor kappa B pathways. Furthermore, lycopene inhibited the adhesion of E. coli O157:H7 to Caco-2 cells by blocking the interaction between E. coli O157:H7 and integrin β1. Lycopene ameliorated DSS-induced colitis by improving epithelial barrier functions and inhibiting E. coli adhesion. Overall, these results show that lycopene may be a promising component for the prevention and treatment of colitis.

Transcriptomics and Metabolomics Reveal Tomato Consumption Alters Hepatic Xenobiotic Metabolism and Induces Steroidal Alkaloid Metabolite Accumulation in Mice

SCOPE

Tomato consumption is associated with many health benefits including lowered risk for developing certain cancers. It is hypothesized that tomato phytochemicals are transported to the liver and other tissues where they alter gene expression in ways that lead to favorable health outcomes. However, the effects of tomato consumption on mammalian liver gene expression and chemical profile are not well defined.

METHODS AND RESULTS

The study hypothesizes that tomato consumption would alter mouse liver transcriptomes and metabolomes compared to a control diet. C57BL/6J mice (n = 11-12/group) are fed a macronutrient matched diet containing either 10% red tomato, 10% tangerine tomato, or no tomato powder for 6 weeks after weaning. RNA-Seq followed by gene set enrichment analyses indicates that tomato type and consumption, in general, altered expression of phase I and II xenobiotic metabolism genes. Untargeted metabolomics experiments reveal distinct clustering between control and tomato fed animals. Nineteen molecular formulas (representing 75 chemical features) are identified or tentatively identified as steroidal alkaloids and isomers of their phase I and II metabolites; many of which are reported for the first time in mammals.

CONCLUSION

These data together suggest tomato consumption may impart benefits partly through enhancing detoxification potential.

Pharmacological therapy of metabolic dysfunction-associated steatotic liver disease-driven hepatocellular carcinoma

In light of a global rise in the number of patients with type 2 diabetes mellitus (T2DM) and obesity, non-alcoholic fatty liver disease (NAFLD), now known as metabolic dysfunction-associated fatty liver disease (MAFLD) or metabolic dysfunction-associated steatotic liver disease (MASLD), has become the leading cause of hepatocellular carcinoma (HCC), with the annual occurrence of MASLD-driven HCC expected to increase by 45%-130% by 2030. Although MASLD has become a serious major public health threat globally, the exact molecular mechanisms mediating MASLD-driven HCC remain an open problem, necessitating future investigation. Meanwhile, emerging studies are focusing on the utility of bioactive compounds to halt the progression of MASLD to MASLD-driven HCC. In this review, we first briefly review the recent progress of the possible mechanisms of pathogenesis and progression for MASLD-driven HCC. We then discuss the application of bioactive compounds to mitigate MASLD-driven HCC through different modulatory mechanisms encompassing anti-inflammatory, lipid metabolic, and gut microbial pathways, providing valuable information for future treatment and prevention of MASLD-driven HCC. Nonetheless, clinical research exploring the effectiveness of herbal medicines in the treatment of MASLD-driven HCC is still warranted.

Nutritionally enriched tomatoes (Solanum lycopersicum L.) grown with wood distillate: chemical and biological characterization for quality assessment

Bio-based products are nowadays useful tools able to affect the productivity and quality of conventionally cultivated crops. Several bio-based products are currently on the market; one of the newest and most promising is the wood distillate (WD) derived from the pyrolysis process of waste biomass after timber. Its foliar application has been widely investigated and shown to promote the antioxidant profile of cultivated crops. WD was used here as additive for the cultivation of tomato (Solanum lycopersicum L.) plants. The application improved quality (chemical) parameters, minerals, polyphenols, and lycopene contents of tomato fruits. The extracts of WD-treated and untreated tomatoes have been chemically and biologically characterized. The 1 H-NMR and ESI-mass spectrometry analyses of the extracts revealed the presence of different fatty acids, amino acids and sugars. In particular, the WD-treated tomatoes showed the presence of pyroglutamic acid and phloridzin derivatives, but also dihydrokaempferol, naringenin glucoside, cinnamic acid, and kaempferol-3-O-glucoside. When tested in cells, the extracts showed a promising anti-inflammatory profile in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. Furthermore, the extracts displayed a slight vasorelaxant activity on rat aorta rings (either endothelium-denuded or endothelium-intact) pre-contracted with phenylephrine or potassium chloride. PRACTICAL APPLICATION: Wood distillate has been used for tomato plant growth. Tomatoes showed improved nutritional parameters, and their extracts displayed antioxidant and anti-inflammatory activities.

Amelioration of Atherosclerosis by lycopene is linked to the modulation of gut microbiota dysbiosis and related gut-heart axis activation in high-fat diet-fed ApoE-/- mice

BACKGROUND

Interplay between gut microbiota and heart, termed "gut-heart" axis, has a crucial role in the pathogenesis of atherosclerosis. Our previous study showed that lycopene possesses anti-inflammatory and anti-atherosclerotic effects, but its link to the gut microbiota is poorly understood. Herein, we surmised that lycopene could regulate the gut microbiota, exert anti-atherosclerotic effect by regulating the "gut-heart" axis.

METHODS

Male ApoE-/- mice were fed a high-fat diet (HFD) with or without lycopene (0.1% w/w) for 19 weeks. Gut microbiota was analyzed by 16 S rRNA sequencing, the protein levels of zonula occludens-1 (ZO-1), occludin, toll-like receptor 4 (TLR4) and phospho-nuclear factor-κB (NF-κB) p65 were measured by Western blotting, the levels of serum inflammatory factors including monocyte chemotactic protein 1 (MCP-1), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and IL-6 were assayed using ELISA kits. Also, the concentrations of serum lipopolysaccharide (LPS), D-lactic acid (D-LA) and diamine peroxidase (DAO) were measured through ELISA method.

RESULTS

The aortic sinus sections revealed that lycopene supplementation significantly reduced the extent of atherosclerotic lesions and inhibited atherosclerosis development caused by HFD. The analysis of gut microbiota showed that lycopene reduced the ratio of Firmicutes/Bacteroides and increased the relative abundance of Verrucomicrobia, Akkermansia and Alloprevotella, which were related to elevated intestinal barrier function and reduced inflammation. Moreover, lycopene up-regulated the expression of intestinal ZO-1 and occludin and decreased serum LPS, D-LA and DAO levels. In addition, lycopene inhibited the expression of TLR4 and phospho-NF-κB p65 in aortic sinus plaque, serum MCP-1, TNF-α, IL-1β, and IL-6 levels were also lowered by lycopene treatment.

CONCLUSIONS

Our results indicated the protective effect of lycopene against atherosclerosis induced by HFD and further revealed that its mechanism might be its prebiotic effect on maintaining gut microbiota homeostasis and improving intestinal barrier function, consequently reducing serum LPS-triggered inflammatory response in the heart.

Plant-based foods and hepatocellular carcinoma: A review on mechanistic understanding

Regardless of etiology, hepatocarcinogenesis is frequently preceded by a distinctive sequence of chronic necroinflammation, compensatory hepatic regeneration, development of hepatic fibrosis, and ultimately cirrhosis. The liver being central immunomodulators, closely maintains immunotolerance. Any dysregulation in this management of immunotolerance is a hallmark of chronic hepatic disease and hepatocellular carcinoma (HCC). Apart from other malignancies, hepatocellular carcinoma accounts for 90% of liver cancers. Several emerging evidences have recognized diet as lifestyle associated risk factor in HCC development. However, natural compounds have the potential to fight hepatoma aggressiveness via inhibition of cellular proliferation and modulation of oncogenic pathways. This review aimed to identify the several plant-based foods for their protective role in HCC prevention by understating the molecular mechanisms involved in inhibition of progression and proliferation of cancer. Information from relevant publications in which several plant-based foods demonstrated protective potential against HCC has been integrated as well as evaluated. For data integration, Science direct, Google scholar, and Scopus websites were used. Nutrition-based approaches in the deterrence of several cancers offer a substantial benefit to currently used medical therapies and should be implemented more often as an adjunct to first-line medical therapy. Furthermore, the inclusion of these plant-based foods (vegetables, fruits, herbs, and spices) may improve general health and decline cancer incidence.

The potential modulation of gut microbiota and oxidative stress by dietary carotenoid pigments

Gut microbiota plays a crucial role in regulating the response to immune checkpoint therapy, therefore modulation of the microbiome with bioactive molecules like carotenoids might be a very effective strategy to reduce the risk of chronic diseases. This review highlights the bio-functional effect of carotenoids on Gut Microbiota modulation based on a bibliographic search of the different databases. The methodology given in the preferred reporting items for systematic reviews and meta-analyses (PRISMA) has been employed for developing this review using papers published over two decades considering keywords related to carotenoids and gut microbiota. Moreover, studies related to the health-promoting properties of carotenoids and their utilization in the modulation of gut microbiota have been presented. Results showed that there can be quantitative changes in intestinal bacteria as a function of the type of carotenoid. Due to the dependency on several factors, gut microbiota continues to be a broad and complex study subject. Carotenoids are promising in the modulation of Gut Microbiota, which favored the appearance of beneficial bacteria, resulting in the protection of villi and intestinal permeability. In conclusion, it can be stated that carotenoids may help to protect the integrity of the intestinal epithelium from pathogens and activate immune cells.

Therapeutic application of natural products: NAD+ metabolism as potential target

BACKGROUND

Nicotinamide adenine dinucleotide (NAD⁺) metabolism is involved in the entire physiopathological process and is critical to human health. Long-term imbalance in NAD⁺ homeostasis is associated with various diseases, including non-alcoholic fatty liver disease, diabetes mellitus, cardiovascular diseases, neurodegenerative disorders, aging, and cancer, making it a potential target for effective therapeutic strategies. Currently, several natural products that target NAD⁺ metabolism have been widely reported to have significant therapeutic effects, but systematic summaries are lacking.

PURPOSE

To summarize the latest findings on the prevention and treatment of various diseases through the regulation of NAD⁺ metabolism by various natural products in vivo and in vitro models, and evaluate the toxicities of the natural products.

METHODS

PubMed, Web of Science, and ScienceDirect were searched using the keywords "natural products sources," "toxicology," "NAD⁺ clinical trials," and "NAD⁺," and/or paired with "natural products" and "diseases" for studies published within the last decade until January 2023.

RESULTS

We found that the natural products mainly include phenols (curcumin, cyclocurcumin, 4-hydroxybenzyl alcohol, salvianolic acid B, pterostilbene, EGCG), flavonoids (pinostrobin, apigenin, acacetin, tilianin, kaempferol, quercetin, isoliquiritigenin, luteolin, silybin, hydroxysafflor yellow A, scutellarin), glycosides (salidroside), quinones (emodin, embelin, β-LAPachone, shikonin), terpenoids (notoginsenoside R1, ginsenoside F2, ginsenoside Rd, ginsenoside Rb1, ginsenoside Rg3, thymoquinone, genipin), pyrazines (tetramethylpyrazine), alkaloids (evodiamine, berberine), and phenylpropanoids (ferulic acid). These natural products have antioxidant, energy-producing, anti-inflammatory, anti-apoptotic and anti-aging effects, which mainly influence the NAMPT/NAD⁺/SIRT, AMPK/SIRT1/PGC-1α, Nrf2/HO-1, PKCs/PARPs/NF-κB, and AMPK/Nrf2/mTOR signaling pathways, thereby regulating NAD⁺ metabolism to prevent and treat various diseases. These natural products have been shown to be safe, tolerable and have fewer adverse effects in various in vivo and in vitro studies and clinical trials.

CONCLUSION

We evaluated the toxic effects of natural products and summarized the available clinical trials on NAD⁺ metabolism, as well as the recent advances in the therapeutic application of natural products targeting NAD⁺ metabolism, with the aim to provide new insights into the treatment of multiple disorders.

The Antioxidant Effect of Dietary Bioactives Arises from the Interplay between the Physiology of the Host and the Gut Microbiota: Involvement of Short-Chain Fatty Acids

The maintenance of redox homeostasis is associated with a healthy status while the disruption of this mechanism leads to the development of various pathological conditions. Bioactive molecules such as carbohydrates accessible to the microbiota (MACs), polyphenols, and polyunsaturated fatty acids (PUFAs) are food components best characterized for their beneficial effect on human health. In particular, increasing evidence suggests that their antioxidant ability is involved in the prevention of several human diseases. Some experimental data indicate that the activation of the nuclear factor 2-related erythroid 2 (Nrf2) pathway-the key mechanism in the maintenance of redox homeostasis-is involved in the beneficial effects exerted by the intake of PUFAs and polyphenols. However, it is known that the latter must be metabolized before becoming active and that the intestinal microbiota play a key role in the biotransformation of some ingested food components. In addition, recent studies, indicating the efficacy of the MACs, polyphenols, and PUFAs in increasing the microbial population with the ability to yield biologically active metabolites (e.g., polyphenol metabolites, short-chain fatty acids (SCFAs)), support the hypothesis that these factors are responsible for the antioxidant action on the physiology of the host. The underlying mechanisms through which MACs, polyphenols, and PUFAs might influence the redox status have not been fully elucidated, but based on the efficacy of SCFAs as Nrf2 activators, their contribution to the antioxidant efficacy of dietary bioactives cannot be excluded. In this review, we aimed to summarize the main mechanisms through which MACs, polyphenols, and PUFAs can modulate the host's redox homeostasis through their ability to directly or indirectly activate the Nrf2 pathway. We discuss their probiotic effects and the role played by the alteration of the metabolism/composition of the gut microbiota in the generation of potential Nrf2-ligands (e.g., SCFAs) in the host's redox homeostasis.

Carotenoids and Their Health Benefits as Derived via Their Interactions with Gut Microbiota

Carotenoids have been related to a number of health benefits. Their dietary intake and circulating levels have been associated with a reduced incidence of obesity, diabetes, certain types of cancer, and even lower total mortality. Their potential interaction with the gut microbiota (GM) has been generally overlooked but may be of relevance, as carotenoids largely bypass absorption in the small intestine and are passed on to the colon, where they appear to be in part degraded into unknown metabolites. These may include apo-carotenoids that may have biological effects because of higher aqueous solubility and higher electrophilicity that could better target transcription factors, i.e., NF-κB, PPARγ, and RAR/RXRs. If absorbed in the colon, they could have both local and systemic effects. Certain microbes that may be supplemented were also reported to produce carotenoids in the colon. Although some bactericidal aspects of carotenoids have been shown in vitro, a few studies have also demonstrated a prebiotic-like effect, resulting in bacterial shifts with health-associated properties. Also, stimulation of IgA could play a role in this respect. Carotenoids may further contribute to mucosal and gut barrier health, such as stabilizing tight junctions. This review highlights potential gut-related health-beneficial effects of carotenoids and emphasizes the current research gaps regarding carotenoid-GM interactions.

Functional foods and their impact on health

Functional foods play an important role in maintaining a healthy lifestyle and reducing the risk factors of various diseases. Most foods have a functional element which is responsible for improving the healthy state. All food substances such as fruits, vegetables, cereals, meat, fish, dairy contain functional ingredients. A wide range of naturally occurring substances from plant and animal sources having active components which play a role in physiological actions deserve attention for their optimal use in maintaining health. The market for functional food is keep on expanding, and the global market is projected to reach a value of at least 91 billion USD soon. Overwhelming evidence from preclinical (in vitro and in vivo) and clinical studies have shown that intake of functional foods could have an impact on the prevention of chronic diseases, especially cancer, cardiovascular diseases, gastrointestinal tract disorders and neurological diseases. Extensive research needs to be done to determine the potential health benefits for the proper application of these foods to improve health state and combat chronic disease progression. The aim of this review is to conduct a thorough literature survey, to understand the various classification of functional foods and their health benefits.

Frizzled 7 modulates goblet and Paneth cell fate, and maintains homeostasis in mouse intestine

Intestinal homeostasis depends on interactions between the intestinal epithelium, the immune system and the microbiota. Because of these complicated connections, there are many problems that need to be solved. Current research has indicated that genes targeted by Wnt signaling are responsible for controlling intestinal stem cell fate and for modulating intestinal homeostasis. Our data show that loss of frizzled 7 (Fzd7), an important element in Wnt signaling, interrupts the differentiation of mouse intestinal stem cells into absorptive progenitors instead of secretory progenitors (precursors of goblet and Paneth cells). The alteration in canonical Wnt and Notch signaling pathways interrupts epithelial homeostasis, resulting in a decrease in physical protection in the intestine. Several phenotypes in our Fzd7-deleted model were similar to the features of enterocolitis, such as shortened intestines, decreased numbers of goblet cells and Paneth cells, and severe inflammation. Additionally, loss of Fzd7 exacerbated the defects in a chemical-induced colitis model and could initiate tumorigenesis. These findings may provide important information for the discovery of efficient therapeutic methods to treat enterocolitis and related cancers in the intestines.

Short-Term Tomato Consumption Alters the Pig Gut Microbiome toward a More Favorable Profile

Diets rich in fruits and vegetables have been shown to exert positive effects on the gut microbiome. However, little is known about the specific effect of individual fruits or vegetables on gut microbe profiles. This study aims to elucidate the effects of tomato consumption on the gut microbiome, as tomatoes account for 22% of vegetable consumption in Western diets, and their consumption has been associated with positive health outcomes. Using piglets as a physiologically relevant model of human metabolism, 20 animals were assigned to either a control or a tomato powder-supplemented diet (both macronutrient matched and isocaloric) for 14 days. The microbiome was sampled rectally at three time points: day 0 (baseline), day 7 (midpoint), and day 14 (end of study). DNA was sequenced using shotgun metagenomics, and reads were annotated using MG-RAST. There were no differences in body weight or feed intake between our two treatment groups. There was a microbial shift which included a higher ratio of Bacteroidota to Bacillota (formerly known as Bacteroidetes and Firmicutes, respectively) and higher alpha-diversity in tomato-fed animals, indicating a shift to a more desirable phenotype. Analyses at both the phylum and genus levels showed global microbiome profile changes (permutational multivariate analysis of variance [PERMANOVA], P ≤ 0.05) over time but not with tomato consumption. These data suggest that short-term tomato consumption can beneficially influence the gut microbial profile, warranting further investigation in humans. IMPORTANCE The composition of the microorganisms in the gut is a contributor to overall health, prompting the development of strategies to alter the microbiome composition. Studies have investigated the role of the diet on the microbiome, as it is a major modifiable risk factor contributing to health; however, little is known about the causal effects of consumption of specific foods on the gut microbiota. A more complete understanding of how individual foods impact the microbiome will enable more evidence-based dietary recommendations for long-term health. Tomatoes are of interest as the most consumed nonstarchy vegetable and a common source of nutrients and phytochemicals across the world. This study aimed to elucidate the effect of short-term tomato consumption on the microbiome, using piglets as a physiologically relevant model to humans. We found that tomato consumption can positively affect the gut microbial profile, which warrants further investigation in humans.

Natural Products for Liver Cancer Treatment: From Traditional Medicine to Modern Drug Discovery

Primary liver cancer was the seventh most diagnosed cancer and the second leading cause of cancer death with about 906,000 cases and 830,000 deaths, respectively, in 2020. Conventional treatment for liver cancer, such as transarterial chemoembolization (TACE) or sorafenib, has limitations in that there is the recurrence of cancer, drug inefficacy, and adverse effects. Traditional medicine and natural products of several regions including Korea, China, Europe, North America, India, and the Middle East have attracted a lot of attention since they have been reported to have anticancer effects with low adverse effects. In this review, several in vivo studies on the effects of natural compounds on liver cancer and clinical trials approving their therapeutic benefits were selected and discussed. As a result of the analysis of these studies, the effects of natural compounds were classified into a few mechanisms: apoptosis, anti-metastasis, and antiangiogenesis. In addition, medications including natural products in clinical trials were observed to exhibit improvements in various liver cancer symptoms and patients’ survival rates. This study presents findings suggestive of the anticancer potential of natural products and their properties in relieving related symptoms.

Effects of Three Feed Additives on the Culturable Microbiota Composition and Histology of the Anterior and Posterior Intestines of Zebrafish (Danio rerio)

Simple Summary

This work is dedicated to the study of the effects of three feed additives that are promising for use in aquaculture on the culturable microbial community and the tissue structure (histology) of the intestines of laboratory zebrafish. The feed additives used in this research have different functional properties: (i) micronutrient chelated compounds, which eliminate mineral nutrition deficiencies; (ii) butyric acid, a postbiotic drug aimed at stimulating intestinal bacteria growth and improving immunity; and (iii) lycopene, a carotenoid and wide-spectrum antioxidant. All of the tested supplements resulted in changes in the intestinal microbial community in both the anterior and posterior intestines. The change in gut microbiota correlated with histological changes in the intestines. The results of the study showed that in most concentrations, the feed additives had a positive effect on certain groups of microorganisms. The method of microbiota research based on microorganism cultivation used in this work makes it possible to evaluate the effect of feed additives on the relative abundance of key representatives of the microbial community.

Abstract

In this study, the effect of three promising feed additives (chelated compounds of trace elements, butyric acid, lycopene) on changes in the culturable microbiota and histological parameters of two sections of the intestines of Danio rerio (zebrafish) was studied. The use of these feed additives can help to eliminate the deficiency of trace elements, modulate the composition of the microbiota due to the postbiotic properties of butyric acid, and reduce oxidative stress when using lycopene. Incorporation of the investigated supplements in the feed resulted in a significant change in the relative abundance of certain groups of microorganisms. The taxonomic diversity of cultured microorganisms did not differ in the anterior and posterior intestines, while there were differences in the relative abundance of these microorganisms. The most sensitive groups of microorganisms were the genera Bacillus and Serratia. A significant effect on the composition of the cultured microbiota was caused by lycopene (in all studied concentrations), leading to a significant increase in the relative abundance of Firmicutes in the anterior gut. Studies of the histological structure of the anterior and posterior guts have shown the relationship between the barrier and secretory functions of the gut and the composition of the microbiota while using butyric acid (1 and 2 g kg⁻¹) and trace element chelated compounds (2 mg kg⁻¹). This culture-dependent method of studying the microbiome makes it possible to assess changes in some representatives of the main groups of microorganisms (Firmicutes and Proteobacteria). Despite the incompleteness of the data obtained by the culture-dependent method, its application makes it possible to assess the bioactive properties of feed and feed additives and their impact on the microbiota involved in digestive processes.

Modulatory role of gut microbiota in cholesterol and glucose metabolism: Potential implications for atherosclerotic cardiovascular disease Atherosclerosis

Accumulating evidence suggests an important role of gut microbiota in physiological processes of host metabolism as well as cardiometabolic disease. Recent advances in metagenomic and metabolomic research have led to discoveries of novel pathways in which intestinal microbial metabolism of dietary nutrients is linked to metabolic profiles and cardiovascular disease risk. A number of metaorganismal circuits have been identified by microbiota transplantation studies and experimental models using germ-free rodents. Many of these pathways involve gut microbiota-related bioactive metabolites that impact host metabolism, in particular lipid and glucose homeostasis, partly via specific host receptors. In this review, we summarize the current knowledge of how the gut microbiome can impact cardiometabolic phenotypes and provide an overview of recent advances of gut microbiome research. Finally, the potential of modulating intestinal microbiota composition and/or targeting microbiota-related pathways for novel preventive and therapeutic strategies in cardiometabolic and cardiovascular diseases will be discussed.

Paradigm Shift in Phytochemicals Research: Evolution from Antioxidant Capacity to Anti-Inflammatory Effect and to Roles in Gut Health and Metabolic Syndrome

Food bioactive components, particularly phytochemicals with antioxidant capacity, have been extensively studied over the past two decades. However, as new analytical and molecular biological tools advance, antioxidants related research has undergone significant paradigm shifts. This review is a high-level overview of the evolution of phytochemical antioxidants research. Early research used chemical models to assess the antioxidant capacity of different phytochemicals, which provided important information about the health potential, but the results were overused and misinterpreted despite the lack of biological relevance (Antioxidants v1.0). This led to findings in the anti-inflammatory properties and modulatory effects of cell signaling of phytochemicals (Antioxidants v2.0). Recent advances in the role of diet in modulating gut microbiota have suggested a new phase of food bioactives research along the phytochemicals-gut microbiota-intestinal metabolites-low-grade inflammation-metabolic syndrome axis (Antioxidants v3.0). Polyphenols and carotenoids were discussed in-depth, and future research directions were also provided.

β-carotene improves fecal dysbiosis and intestinal dysfunctions in a mouse model of vitamin A deficiency

Vitamin A deficiency (VAD) results in intestinal inflammation, increased redox stress and reactive oxygen species (ROS) levels, imbalanced inflammatory and immunomodulatory cytokines, compromised barrier function, and perturbations of the gut microbiome. To combat VAD dietary interventions with β-carotene, the most abundant precursor of vitamin A, are recommended. However, the impact of β-carotene on intestinal health during VAD has not been fully clarified, especially regarding the VAD-associated intestinal dysbiosis. Here we addressed this question by using Lrat^-/-Rbp^-/- (vitamin A deficient) mice deprived of dietary preformed vitamin A and supplemented with β-carotene as the sole source of the vitamin, alongside with WT (vitamin A sufficient) mice. We found that dietary β-carotene impacted intestinal vitamin A status, barrier integrity and inflammation in both WT and Lrat^-/-Rbp^-/- (vitamin A deficient) mice on the vitamin A-free diet. However, it did so to a greater extent under overt VAD. Dietary β-carotene also modified the taxonomic profile of the fecal microbiome, but only under VAD. Given the similarity of the VAD-associated intestinal phenotypes with those of several other disorders of the gut, collectively known as Inflammatory Bowel Disease (IBD) Syndrome, these findings are broadly relevant to the effort of developing diet-based intervention strategies to ameliorate intestinal pathological conditions.

Effects of Non-Polar Dietary and Endogenous Lipids on Gut Microbiota Alterations: The Role of Lipidomics

Advances in sequencing technologies over the past 15 years have led to a substantially greater appreciation of the importance of the gut microbiome to the health of the host. Recent outcomes indicate that aspects of nutrition, especially lipids (exogenous or endogenous), can influence the gut microbiota composition and consequently, play an important role in the metabolic health of the host. Thus, there is an increasing interest in applying holistic analytical approaches, such as lipidomics, metabolomics, (meta)transcriptomics, (meta)genomics, and (meta)proteomics, to thoroughly study the gut microbiota and any possible interplay with nutritional or endogenous components. This review firstly summarizes the general background regarding the interactions between important non-polar dietary (i.e., sterols, fat-soluble vitamins, and carotenoids) or amphoteric endogenous (i.e., eicosanoids, endocannabinoids-eCBs, and specialized pro-resolving mediators-SPMs) lipids and gut microbiota. In the second stage, through the evaluation of a vast number of dietary clinical interventions, a comprehensive effort is made to highlight the role of the above lipid categories on gut microbiota and vice versa. In addition, the present status of lipidomics in current clinical interventions as well as their strengths and limitations are also presented. Indisputably, dietary lipids and most phytochemicals, such as sterols and carotenoids, can play an important role on the development of medical foods or nutraceuticals, as they exert prebiotic-like effects. On the other hand, endogenous lipids can be considered either prognostic indicators of symbiosis or dysbiosis or even play a role as specialized mediators through dietary interventions, which seem to be regulated by gut microbiota.

Tomatoes: An Extensive Review of the Associated Health Impacts of Tomatoes and Factors That Can Affect Their Cultivation

Simple Summary

The research outlined in this review paper discusses potential health benefits associated with a diet enriched with tomatoes and tomato products. This includes details of previous studies investigating the anticancer properties of tomatoes, protection against cardiovascular and neurodegenerative diseases and diabetes, maintenance of a healthy gut microbiome, and improved skin health, fertility, immune response, and exercise recovery. The specific parts of a tomato fruit that contribute these health benefits are also outlined. The potential disadvantages to a tomato-rich diet are detailed, especially the consumption of supplements that contain compounds found in tomatoes, such as lycopene. This review also discusses how the cultivation of tomato plants can affect the nutritional value of the fruit harvested. Different environmental growing conditions such as light intensity, growing media, and temperature are explained in terms of the impact they have on the quality of fruit, its nutrient content, and hence the potential health benefits acquired from eating the fruit.

Abstract

This review outlines the health benefits associated with the regular consumption of tomatoes and tomato products. The first section provides a detailed account of the horticultural techniques that can impact the quality of the fruit and its nutritional properties, including water availability, light intensity, temperature, and growing media. The next section provides information on the components of tomato that are likely to contribute to its health effects. The review then details some of the health benefits associated with tomato consumption, including anticancer properties, cardiovascular and neurodegenerative diseases and skin health. This review also discusses the impact tomatoes can have on the gut microbiome and associated health benefits, including reducing the risk of inflammatory bowel diseases. Other health benefits of eating tomatoes are also discussed in relation to effects on diabetes, the immune response, exercise recovery, and fertility. Finally, this review also addresses the negative effects that can occur as a result of overconsumption of tomato products and lycopene supplements.

Therapeutic promise of carotenoids as antioxidants and anti-inflammatory agents in neurodegenerative disorders

Neurodegenerative disorders (NDs) including Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, Huntington's disease, and multiple sclerosis have various disease-specific causal factors and pathological features. A very common characteristic of NDs is oxidative stress (OS), which takes place due to the elevated generation of reactive oxygen species during the progression of NDs. Furthermore, the pathological condition of NDs including an increased level of protein aggregates can further lead to chronic inflammation because of the microglial activation. Carotenoids (CTs) are naturally occurring pigments that play a significant role in averting brain disorders. More than 750 CTs are present in nature, and they are widely available in plants, microorganisms, and animals. CTs are accountable for the red, yellow, and orange pigments in several animals and plants, and these colors usually indicate various types of CTs. CTs exert various bioactive properties because of its characteristic structure, including anti-inflammatory and antioxidant properties. Due to the protective properties of CTs, levels of CTs in the human body have been markedly linked with the prevention and treatment of multiple diseases including NDs. In this review, we have summarized the relationship between OS, neuroinflammation, and NDs. In addition, we have also particularly focused on the antioxidants and anti-inflammatory properties of CTs in the management of NDs.

Phytochemicals as an Alternative or Integrative Option, in Conjunction with Conventional Treatments for Hepatocellular Carcinoma

Simple Summary

Hepatocellular carcinoma (HCC) is globally ranked as the sixth most diagnosed cancer, and the second most deadly cancer. To worsen matters, there are only limited therapeutic options currently available; therefore, it is necessary to find a reservoir from which new HCC treatments may be acquired. The field of phytomedicine may be the solution to this problem, as it offers an abundance of plant-derived molecules, which show capabilities of being effective against HCC proliferation, invasion, migration, and metastasis. In our review, we collect and analyze current evidence regarding these promising phytochemical effects on HCC, and delve into their potential as future chemotherapies. Additionally, information on the signaling behind these numerous phytochemicals is provided, in an attempt to understand their mechanisms. This review makes accessible the current body of knowledge pertaining to phytochemicals as HCC treatments, in order to serve as a reference and inspiration for further research into this subject.

Abstract

Hepatocellular carcinoma (HCC) is the most abundant form of liver cancer. It accounts for 75–85% of liver cancer cases and, though it ranks globally as the sixth most common cancer, it ranks second in cancer-related mortality. Deaths from HCC are usually due to metastatic spread of the cancer. Unfortunately, there are many challenges and limitations with the latest HCC therapies and medications, making it difficult for patients to receive life-prolonging care. As there is clearly a high demand for alternative therapy options for HCC, it is prudent to turn to plants for the solution, as their phytochemicals have long been used and revered for their many medicinal purposes. This review explores the promising phytochemical compounds identified from pre-clinical and clinical trials being used either independently or in conjunction with already existing cancer therapy treatments. The phytochemicals discussed in this review were classified into several categories: lipids, polyphenols, alkaloids, polysaccharides, whole extracts, and phytochemical combinations. Almost 80% of the compounds failed to progress into clinical studies due to lack of information regarding the toxicity to normal cells and bioavailability. Although large obstacles remain, phytochemicals can be used either as an alternative or integrative therapy in conjunction with existing HCC chemotherapies. In conclusion, phytochemicals have great potential as treatment options for hepatocellular carcinoma.

Curcumae Ameliorates Diethylnitrosamine-Induced Hepatocellular Carcinoma via Alteration of Oxidative Stress, Inflammation and Gut Microbiota

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) increased the risk factor of hepatocellular carcinoma (HCC). NAFLD induces the hepatic-related cancer deaths mostly in middle-aged men. NAFLD enhanced the inflammatory reaction and oxidative stress in the hepatic tissue. Curcumae exhibited the anti-inflammatory and antioxidant effects. In this study, we made an attempt to scrutinize the protective effect of curcumae on obesity-induced HCC via alteration of inflammation, oxidative stress and gut microbiota.

METHODS

The rats used in this experiment were Wistar rats, 100 mg/kg intraperitoneal injection of diethylnitrosamine (hepatic carcinogen) was used at 2 weeks. After 6 weeks of the experimental study, the rats were randomly divided into high-fat diet (HFD) with or without curcumae-treated group rats and received the treatment for 22 weeks. Hepatic, non-hepatic, cardiac, antioxidant, pro-inflammatory and inflammatory were estimated at the end of the study. The stools of the experimental rats were collected for estimating the gut microbiota.

RESULTS

Curcumae-treated group rats exposed reduction of the hepatic nodules in hepatic tissue. Curcumae significantly (P<0.001) diminished the level of hepatic parameters and antioxidant parameters in the serum. Curcumae significantly (P<0.001) suppressed the pro-inflammatory cytokines level, viz. interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interleukin-2 (IL-2), interleukin-7 (IL-7) and augmented the level of interleukin-10 (IL-10) in the serum and hepatic tissue. Curcumae significantly (P<0.001) suppressed inflammatory mediators including cyclooxygenase (COX-2), prostaglandin E2 (PGE2) and nuclear factor kappa B (NF-κB) in the serum and hepatic tissue. Furthermore, curcumae increased the gut microbial diversity and richness and decreased the relative abundance of genus Mucispirillum and Clostridium, respectively.

CONCLUSION

Curcumae prevents HFD-induced inflammation during the hepatic carcinoma by modulating the oxidative stress, inflammatory reaction and gut microbiota.

Alteration of fecal microbiota by fucoxanthin results in prevention of colorectal cancer in AOM/DSS mice

Fucoxanthin (Fx), a marine carotenoid found in edible brown algae, is well known for having anticancer properties. The gut microbiota has been demonstrated as a hallmark for colorectal cancer progression in both humans and rodents. However, it remains unclear whether the gut microbiota is associated with the anticancer effect of Fx. We investigated the chemopreventive potency of Fx and its effect on gut microbiota in a mouse model of inflammation-associated colorectal cancer (by azoxymethane/dextran sulfate sodium treatment). Fx administration (30 mg/kg bw) during a 14 week period significantly inhibited the multiplicity of colorectal adenocarcinoma in mice. The number of apoptosis-like cleaved caspase-3high cells increased significantly in both colonic adenocarcinoma and mucosal crypts. Fx administration significantly suppressed Bacteroidlales (f_uc; g_uc) (0.3-fold) and Rikenellaceae (g_uc) (0.6-fold) and increased Lachnospiraceae (g_uc) (2.2-fold), compared with those of control mice. Oral administration of a fecal suspension obtained from Fx-treated mice, aimed to enhance Lachnospiraceae, suppress the number of colorectal adenocarcinomas in azoxymethane/dextran sulfate sodium-treated mice with a successful increase in Lachnospiraceae in the gut. Our findings suggested that an alteration in gut microbiota by dietary Fx might be an essential factor in the cancer chemopreventive effect of Fx in azoxymethane/dextran sulfate sodium-treated mice.

A novel therapeutic strategy for hepatocellular carcinoma: Immunomodulatory mechanisms of selenium and/or selenoproteins on a shift towards anti-cancer

Selenium (Se) is an essential trace chemical element that is widely distributed worldwide. Se exerts its immunomodulatory and nutritional activities in the human body in the form of selenoproteins. Se has increasingly appeared as a potential trace element associated with many human diseases, including hepatocellular carcinoma (HCC). Recently, increasing evidence has suggested that Se and selenoproteins exert their immunomodulatory effects on HCC by regulating the molecules of oxidative stress, inflammation, immune response, cell proliferation and growth, angiogenesis, signaling pathways, apoptosis, and other processes in vitro cell studies and in vivo animal studies. Se concentrations are generally low in tissues of patients with HCC, such as blood, serum, scalp hair, and toenail. However, Se concentrations were higher in HCC patient tissues after Se supplementation than before supplementation. This review summarizes the significant relationship between Se and HCC, and details the role of Se as a novel immunomodulatory or immunotherapeutic approach against HCC.

Phytochemicals as modifiers of gut microbial communities

A healthy gut microbiota (GM) is paramount for a healthy lifestyle. Alterations of the GM have been involved in the aetiology of several chronic diseases, including obesity and type 2 diabetes, as well as cardiovascular and neurodegenerative diseases. In pathological conditions, the diversity of the GM is commonly reduced or altered, often toward an increased Firmicutes/Bacteroidetes ratio. The colonic fermentation of dietary fiber has shown to stimulate the fraction of bacteria purported to have beneficial health effects, acting as prebiotics, and to increase the production of short chain fatty acids, e.g. propionate and butyrate, while also improving gut epithelium integrity such as tight junction functionality. However, a variety of phytochemicals, often associated with dietary fiber, have also been proposed to modulate the GM. Many phytochemicals possess antioxidant and anti-inflammatory properties that may positively affect the GM, including polyphenols, carotenoids, phytosterols/phytostanols, lignans, alkaloids, glucosinolates and terpenes. Some polyphenols may act as prebiotics, while carotenoids have been shown to alter immunoglobulin A expression, an important factor for bacteria colonization. Other phytochemicals may interact with the mucosa, another important factor for colonization, and prevent its degradation. Certain polyphenols have shown to influence bacterial communication, interacting with quorum sensing. Finally, phytochemicals can be metabolized in the gut into bioactive constituents, e.g. equol from daidzein and enterolactone from secoisolariciresinol, while bacteria can use glycosides for energy. In this review, we strive to highlight the potential interactions between prominent phytochemicals and health benefits related to the GM, emphasizing their potential as adjuvant strategies for GM-related diseases.

Dietary lycopene attenuates cigarette smoke-promoted nonalcoholic steatohepatitis by preventing suppression of antioxidant enzymes in ferrets

Cigarette smoke (CS) is an independent risk factor in development of nonalcoholic steatohepatitis (NASH) and fibrosis. Lycopene, a carotenoid naturally occurring in tomatoes, has been shown to be a protective agent against tobacco carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced NASH. In the present study using a ferret model we investigated whether CS promotes NASH and whether dietary lycopene can inhibit CS-promoted NASH development, and if so, what potential mechanisms were involved. Ferrets were divided into 4 groups (n=12-16/group): control, NNK/CS exposed, NNK/CS plus low-dose lycopene (2.2 mg/kg BW/day), and NNK/CS plus high-dose lycopene (6.6 mg/kg BW/day) groups, for 26 weeks. Results showed that hepatic steatosis, infiltrates of inflammatory cells, and the number and size of inflammatory foci in liver, together with key genes involved in hepatic fibrogenesis were higher in the NNK/CS group compared to the control group; a lycopene diet reversed these changes to the levels of the control group. Interestingly, a major lycopene cleavage enzyme, beta-carotene 9',10'-oxygenase (BCO2), which recently has been recognized to play metabolic roles beyond cleavage function, was down-regulated by NNK/CS exposure, but this decrease was prevented by lycopene feeding. NNK/CS exposure also downregulated liver expression of antioxidant enzymes and upregulated oxidative stress marker, which were all prevented by lycopene. In conclusion, our results suggest that CS can promote development of NASH and liver fibrosis in ferrets, which is associated with downregulation of BCO2 and impairment of antioxidant system in liver; dietary lycopene may inhibit CS-promoted NASH by preventing suppression of BCO2 and decline in antioxidant network.

The gut microbiome-bile acid axis in hepatocarcinogenesis

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy and is a leading cause of cancer-related deaths globally, with few effective therapeutic options. Bile acids (BAs) are synthesized from cholesterol in the liver and can be modulated by farnesoid X receptor (FXR) and G-protein coupled BA receptor 1 (GPBAR1/TGR5). Alterations in BAs can affect hepatic metabolic homeostasis and contribute to the pathogenesis of liver cancer. Increasing evidence points to the key role of bacterial microbiota in the promotion and development of liver cancer. They are also involved in the regulation of BA synthesis and metabolism. The purpose of this review is to integrate related articles involving gut microbiota, BAs and HCC, and review how the gut microbiota-BA signaling axis can possibly influence the development of HCC.

The Potential Gut Microbiota-Mediated Treatment Options for Liver Cancer

Primary liver cancer is one of the leading causes of cancer death worldwide. Surgical and non-surgical treatments are optional for liver cancer therapy based on the cancer stage. Accumulating studies show that the gut–liver axis influences the progression of liver diseases, including liver inflammation, fibrosis, cirrhosis, and cancer. However, the role of gut microbiota and their derived components and metabolites in liver cancer remains to be further clarified. In this review, we discuss the roles of gut microbiota and specific bacterial species in HCC and the strategies to modulate gut microbiota to improve antitumor therapy. Given the limitation of current treatments, gut microbiota-mediated therapy is a potential option for HCC treatment, including fiber diet and vegetable diet, antimicrobials, probiotics, and pharmaceutical inhibitors. Also, gut microbiota can be used as a marker for early diagnosis of HCC. HCC occurs dependent on various environmental and genetic factors, including diet and sex. Furthermore, gut microbiota impacts the immunotherapy of HCC treatment. Therefore, a better understanding of the role of the gut–liver axis in liver cancer is critically important to improve therapeutic efficacy.

Extraction and Analysis by HPLC-DAD of Carotenoids in Human Faeces from Spanish Adults

Carotenoids are bioactive compounds with widely accepted health benefits. Their quantification in human faeces can be a useful non-invasive approach to assess their bioavailability. Identification and quantification of major dietary carotenoids in human faeces was the aim of the present study. Faeces and dietary intake were obtained from 101 healthy adults (45-65 years). Carotenoid concentrations were determined by HPLC in faeces and by 3-day food records in dietary intake. Carotenoids quantified in faeces (µg/g dry weight, median) were: β-carotene (39.5), lycopene (20), lutein (17.5), phytoene (11.4), zeaxanthin (6.3), β-cryptoxanthin (4.5), phytofluene (2.9). α-carotene (5.3) and violaxanthin were found 75.5% and 7.1% of the faeces. The carotenoids found in the highest concentrations corresponded to the ones consumed in the greatest amounts (µg/d): lycopene (13,146), phytoene (2697), β-carotene (1812), lutein+zeaxanthin (1148). Carotenoid concentration in faeces and in dietary intake showed correlation for the total non-provitamin A carotenoids (r = 0.302; p = 0.003), phytoene (r = 0.339; p = 0.001), phytofluene (r = 0.279; p = 0.005), lycopene (0.223; p = 0.027), lutein+zeaxanthin (r = 0.291; p = 0.04) and β-cryptoxanthin (r = 0.323; p = 0.001). A high proportion of dietary carotenoids, especially those with provitamin A activity and some of their isomers, reach the large intestine, suggesting a low bioavailability of their intact forms.

Identification of Potential Key Genes for Pathogenesis and Prognosis in Prostate Cancer by Integrated Analysis of Gene Expression Profiles and the Cancer Genome Atlas

Background: Prostate cancer (PCa)is a malignancy of the urinary system with a high incidence, which is the second most common male cancer in the world. There are still huge challenges in the treatment of prostate cancer. It is urgent to screen out potential key biomarkers for the pathogenesis and prognosis of PCa.

Methods: Multiple gene differential expression profile datasets of PCa tissues and normal prostate tissues were integrated analysis by R software. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of the overlapping Differentially Expressed Genes (DEG) were performed. The STRING online database was used in conjunction with Cytospace software for protein-protein interaction (PPI) network analysis to define hub genes. The relative mRNA expression of hub genes was detected in Gene Expression Profiling Interactive Analysis (GEPIA) database. A prognostic gene signature was identified by Univariate and multivariate Cox regression analysis.

Results: Three hundred twelve up-regulated genes and 85 down-regulated genes were identified from three gene expression profiles (GSE69223, GSE3325, GSE55945) and The Cancer Genome Atlas Prostate Adenocarcinoma (TCGA-PRAD) dataset. Seven hub genes (FGF2, FLNA, FLNC, VCL, CAV1, ACTC1, and MYLK) further were detected, which related to the pathogenesis of PCa. Seven prognostic genes (BCO1, BAIAP2L2, C7, AP000844.2, ASB9, MKI67P1, and TMEM272) were screened to construct a prognostic gene signature, which shows good predictive power for survival by the ROC curve analysis.

Conclusions: We identified a robust set of new potential key genes in PCa, which would provide reliable biomarkers for early diagnosis and prognosis and would promote molecular targeting therapy for PCa.

Association between Dietary Tomato Intake and the Risk of Hepatocellular Carcinoma: The Singapore Chinese Health Study

BACKGROUND

Intake of tomato and/or lycopene has been associated with reduced risk of several cancers, but there is no report on the association with risk of hepatocellular carcinoma (HCC).

METHODS

The associations of tomato and lycopene consumption with risk of HCC were examined in the Singapore Chinese Health Study, a prospective cohort of 63,257 Chinese ages 45 to 74 years at enrollment. Diet was assessed using a validated semiquantitative food frequency questionnaire. Cox proportional hazard regression models were used to estimate HR and its 95% confidence interval (CI) of HCC with the consumption of tomato and lycopene among all cohort participants, and unconditional logistic regression was used to assess the association by hepatitis B surface antigen (HBsAg) positivity in a nested case-control study.

RESULTS

After a mean follow-up of 17.6 years, 561 incident HCC cases were identified. Higher tomato intake was associated with lower risk of HCC after adjustment for potential confounders (P _trend < 0.001). Compared with the lowest quartile, HRs (95% CIs) of HCC for the second, third, and fourth quartile of tomato intake were 0.70 (0.56-0.88), 0.73 (0.58-0.92), and 0.63 (0.49-0.81). Among HBsAg-negative individuals, the inverse association remained (P _trend = 0.03). There was no association between lycopene intake and HCC risk (P _trend = 0.54).

CONCLUSIONS

Tomato intake may offer protection against the development of HCC, particularly among individuals without chronic infection with hepatitis B virus.

IMPACT

Tomato intake is a low-cost preventative measure against HCC that may help reduce risk due to increasing rates of nonalcoholic fatty liver disease.

Mechanistic understanding of β-cryptoxanthin and lycopene in cancer prevention in animal models

To better understand the potential function of carotenoids in the chemoprevention of cancers, mechanistic understanding of carotenoid action on genetic and epigenetic signaling pathways is critically needed for human studies. The use of appropriate animal models is the most justifiable approach to resolve mechanistic issues regarding protective effects of carotenoids at specific organs and tissue sites. While the initial impetus for studying the benefits of carotenoids in cancer prevention was their antioxidant capacity and pro-vitamin A activity, significant advances have been made in the understanding of the action of carotenoids with regards to other mechanisms. This review will focus on two common carotenoids, provitamin A carotenoid β-cryptoxanthin and non-provitamin A carotenoid lycopene, as promising chemopreventive agents or chemotherapeutic compounds against cancer development and progression. We reviewed animal studies demonstrating that β-cryptoxanthin and lycopene effectively prevent the development or progression of various cancers and the potential mechanisms involved. We highlight recent research that the biological functions of β-cryptoxanthin and lycopene are mediated, partially via their oxidative metabolites, through their effects on key molecular targeting events, such as NF-κB signaling pathway, RAR/PPARs signaling, SIRT1 signaling pathway, and p53 tumor suppressor pathways. The molecular targets by β-cryptoxanthin and lycopene, offer new opportunities to further our understanding of common and distinct mechanisms that involve carotenoids in cancer prevention. This article is part of a Special Issue entitled Carotenoids recent advances in cell and molecular biology edited by Johannes von Lintig and Loredana Quadro.

Role of Gut Microbiota in Hepatocarcinogenesis

Hepatocellular carcinoma (HCC), one of the leading causes of death worldwide, has a causal nexus with liver injury, inflammation, and regeneration that accumulates over decades. Observations from recent studies have accounted for the involvement of the gut–liver axis in the pathophysiological mechanism responsible for HCC. The human intestine nurtures a diversified colony of microorganisms residing in the host ecosystem. The intestinal barrier is critical for conserving the normal physiology of the gut microbiome. Therefore, a rupture of this barrier or dysbiosis can cause the intestinal microbiome to serve as the main source of portal-vein endotoxins, such as lipopolysaccharide, in the progression of hepatic diseases. Indeed, increased bacterial translocation is a key sign of HCC. Considering the limited number of clinical studies on HCC with respect to the microbiome, we focus on clinical as well as animal studies involving the gut microbiota, with the current understandings of the mechanism by which the intestinal dysbiosis promotes hepatocarcinogenesis. Future research might offer mechanistic insights into the specific phyla targeting the leaky gut, as well as microbial dysbiosis, and their metabolites, which represent key pathways that drive HCC-promoting microbiome-mediated liver inflammation and fibrosis, thereby restoring the gut barrier function.