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Role of Food habit and Enteric microbes in the development of colon cancer
... The percentage of the carbohydrate was determined by the sum of fat content, protein content, ash content, fibre and moisture which was subtracted from 100 (Obayomi et al., 2024c). ...
The mammalian target of rapamycin (mTOR) is a protein kinase that controls cellular metabolism, catabolism, immune responses,autophagy, survival, proliferation, and migration, to maintain cellular homeostasis. The mTOR signaling cascade consists of twodistinct multi-subunit complexes named mTOR complex 1/2 (mTORC1/2). mTOR catalyzes the phosphorylation of several criticalproteins like AKT, protein kinase C, insulin growth factor receptor (IGF-1R), 4E binding protein 1 (4E-BP1), ribosomal protein S6kinase (S6K), transcription factor EB (TFEB), sterol-responsive element-binding proteins (SREBPs), Lipin-1, and Unc-51-likeautophagy-activating kinases. mTOR signaling plays a central role in regulating translation, lipid synthesis, nucleotide synthesis,biogenesis of lysosomes, nutrient sensing, and growth factor signaling. The emerging pieces of evidence have revealed that theconstitutive activation of the mTOR pathway due to mutations/amplification/deletion in either mTOR and its complexes (mTORC1and mTORC2) or upstream targets is responsible for aging, neurological diseases, and human malignancies. Here, we provide thedetailed structure of mTOR, its complexes, and the comprehensive role of upstream regulators, as well as downstream effectors ofmTOR signaling cascades in the metabolism, biogenesis of biomolecules, immune responses, and autophagy. Additionally, wesummarize the potential of long noncoding RNAs (lncRNAs) as an important modulator of mTOR signaling. Importantly, we havehighlighted the potential of mTOR signaling in aging, neurological disorders, human cancers, cancer stem cells, and drug resistance.Here, we discuss the developments for the therapeutic targeting of mTOR signaling with improved anticancer efficacy for thebenefit of cancer patients in clinics.
A growing interest in the medicinal values of foods can be assessed by the rapidity
of research publications on foods that exert health benefits. Many foods that are of
health benefit to humans, irrespective of their origin (plants, animals) and
subjected level of processing (fermentation, cooking, warming, freezing, vacuumpackaging), are variously designated in scientific literature based on their
biofunction. Plant-based foods’ application vagaries, momentum, and research
orientation regarding their health functionality awareness are scarcely studied by
bibliometrics from a global perspective. Therefore, a bibliometric search was
performed on the Scopus database from 2011 (January) to 2021 (April) using a
range of search keys covering reports of conceptualized consumable plant-derived foods with health-promoting potential. A total of 362,309 documents on medicinal foods of plant origin were obtained from the database. The data were obtained in comma-separated values (CSV) format and analyzed with Microsoft Excel tools. Of the total documents from the Scopus database on the study, 8.01% (29,036) were contributed by African researchers. Comparatively, lead contributors (global; Africa) by group disciplines include biochemistry, genetics, and molecular biology (118,896; 8,236); pharmacology, toxicology, and pharmaceutics (104,530; 8,581); agricultural and biological sciences (99,053; 9,610), respectively. Similarly, lead contributors by country include China (73,977), India (44,898), USA (44,582), and Nigeria (4,680). This observation shows a higher research propensity towards
plant-derived medicinal foods in populous nations due to factors like dietary
culture, an increase in vegan and health-nutrition enthusiast populations, and the
emergent concerns with the therapeutic use of synthetic pharmaceuticals. The
analyzed results gave insights into the research orientation of plant-based foods
that promote human health on a global stage and provide future research
directions. Knowledge of the various application of plant-based foods may
potentiate the United Nations Sustainable Goals initiative on responsible
consumption (SDG 12), and health and wellbeing (SDG 3) among the global
population.
Bile acids (BA) are amphipathic molecules originating from cholesterol in the liver and from microbiota-driven biotransformation in the colon. In the gut, BA play a key role in fat digestion and absorption and act as potent signaling molecules on the nuclear farnesoid X receptor (FXR) and membrane-associated G protein-coupled BA receptor-1 (GPBAR-1). BA are, therefore, involved in the maintenance of gut barrier integrity, gene expression, metabolic homeostasis, and microbiota profile and function. Disturbed BA homeostasis can activate pro-inflammatory pathways in the gut, while inflammatory bowel diseases (IBD) can induce gut dysbiosis and qualitative and/or quantitative changes of the BA pool. These factors contribute to impaired repair capacity of the mucosal barrier, due to chronic inflammation. A better understanding of BA-dependent mechanisms paves the way to innovative therapeutic tools by administering hydrophilic BA and FXR agonists and manipulating gut microbiota with probiotics and prebiotics. We discuss the translational value of pathophysiological and therapeutic evidence linking BA homeostasis to gut inflammation in IBD.
The intestine is the largest interface between the internal body and the external environment. The intestinal barrier is a dynamic system influenced by the composition of the intestinal microbiome and the activity of intercellular connections, regulated by hormones, dietary components, inflammatory mediators, and the enteric nervous system (ENS). Over the years, it has become increasingly evident that maintaining a stable intestinal barrier is crucial to prevent various potentially harmful substances and pathogens from entering the internal environment. Disruption of the barrier is referred to as 'leaky gut' or leaky gut wall syndrome and seems to be characterized by the release of bacterial metabolites and endotoxins, such as lipopolysaccharide (LPS), into the circulation. This condition, mainly caused by bacterial infections, oxidative stress, high-fat diet, exposure to alcohol or chronic allergens, and dysbiosis, appear to be highly connected with the development and/or progression of several metabolic and autoimmune systemic diseases, including obesity, non-alcoholic fatty liver disease (NAFLD), neurodegeneration, cardiovascular disease, inflammatory bowel disease, and type 1 diabetes mellitus (T1D). In this review, starting from a description of the mechanisms that enable barrier homeostasis and analyzing the relationship between this complex ecosystem and various pathological conditions, we explore the role of the gut barrier in driving systemic inflammation, also shedding light on current and future therapeutic interventions.
Prebiotics have become an important functional food because of their potential for modulating the gut microbiota and metabolic activities. However, different prebiotics can stimulate the growth of different probiotics. The optimization of prebiotics was focused on in this study in order to stimulate the representative probiotics’ growth (Lacticaseibacillus rhamnosus (previously Lactobacillus rhamnosus) and Bifidobacterium animalis subsp. lactis) and their function. The culture medium was supplemented with three prebiotics, including inulin (INU), fructooligosaccharides (FOS), and galactooligosaccharides (GOS). All prebiotics can clearly stimulate the growth of probiotic strains in both monoculture and co-culture. The specific growth rates of L. rhamnosus and B. animalis subsp. lactis were shown in GOS (0.019 h−1) and FOS (0.023 h−1), respectively. The prebiotic index (PI) scores of INU (1.03), FOS (0.86), and GOS (0.84) in co-culture at 48 h were significantly higher than the control (glucose). The mixture of prebiotics to achieve high quality was optimized using the Box–Behnken design. The optimum prebiotic ratios of INU, FOS, and GOS were 1.33, 2.00, and 2.67% w/v, respectively, with the highest stimulated growth of probiotic strains occurring with the highest PI score (1.03) and total short chain fatty acid concentration (85.55 µmol/mL). The suitable ratio of mixed prebiotics will function as a potential ingredient for functional foods or colonic foods.
Wine is essential in every celebration but it is very expensive in countries where grape is not grown. Agadagidi, an effervescent wine analogue with sweet-sour taste is locally produced from overripe plantain which is abundant in the Tropics. This research produced agadagidi by sulphiting the must with or without inoculating with Saccharomyces cerevisiae strain isolated from spontaneous fermentation. Some of the samples were also pasteurized with a view to producing agadagidi with consistent quality. Microorganisms were enumerated, isolated and identified during storage, sugars, pH, TTA and sensory properties were also assessed using standard methods. The result showed that the range of TVC, LAB, and fungi count were 5.571 – 9.076 log cfu/ml, 2.717- 9.253 log cfu/ml and 4.079 - 9.418 log cfu/ml respectively. Microorganisms isolated were Saccharomyces cerevisiae, Saccharomyces bayanus, Pichia kluyveri, Candida albicans, Bacillus pumilus, Lactobacillus plantarum, Bacillus subtilis and Leuconostoc oenos. The reducing sugar was higher in unpasteurized samples than pasteurized sample at the beginning of storage. Total sugar generally decreased while the TTA increased during storage. The sensory score showed that all unpasteurized samples and pasteurized sample without isolate and sulphite were accepted by the panelists. This study therefore suggests the use of sulphite with or without starter culture in the production of agadagidi with consistent quality.
Inflammatory bowel diseases (IBDs) are characterized by inflammation in the gastrointestinal tract and include Ulcerative Colitis and Crohn's Disease. These diseases are costly to health services, substantially reduce patients' quality of life, and can lead to complications such as cancer and even death. Symptoms include abdominal pain, stool bleeding, diarrhea, and weight loss. The treatment of these diseases is symptomatic, seeking disease remission. The intestine is colonized by several microorganisms, such as fungi, viruses, and bacteria, which constitute the intestinal microbiota (IM). IM bacteria promotes dietary fibers fermentation and produces short-chain fatty acids (SCFAs) that exert several beneficial effects on intestinal health. SCFAs can bind to G protein-coupled receptors, such as GPR41 and GPR43, promoting improvements in the intestinal barrier, anti-inflammatory, and antioxidant effects. Thus, SCFAs could be a therapeutic tool for IBDs. However, the mechanisms involved in these beneficial effects of SCFAs remain poorly understood. Therefore, this paper aims to provide a review addressing the main aspects of IBDs, and a more detailed sight of SCFAs, focusing on the main effects on different aspects of the intestine with an emphasis on IBDs.
Kunun-zaki is a cereal-based fermented refreshing drink popular in the Northern region of Nigeria and has become accepted in other parts of the country. Granted is the fact that protein is deficient in fermented cereal beverages. In an attempt to find solution to this problem, this study investigated the upshot of groundnut inclusion in kunun-zaki from millet so as to confirm if the inclusion will increase protein content in the millet-based beverage. Groundnut-fortified kunun-zaki (GFK) was prepared at different ratios of millet and groundnut blends. Physicochemical properties were determined. Microbial counts and sensory qualities of the kunun-zaki were also evaluated for safety and acceptability. Results showed that addition of groundnut to kunun-zaki increased the protein composition significantly (p˂0.05) from 1.51 to 5.45%, with 50% millet + 50% groundnut blend (50MT:50GT) having the highest concentration. Groundnut inclusion increased ash and crude fat contents but decreased crude fiber content. The turbidity and pH varied between 60.0-145.1 and 5.2-5.4, respectively. There was no significant difference in the overall consumer’s acceptability of the GFK samples compared to the control, however, in appearance, there were significant differences with 50MT:50GT, having the highest score of 7.03 out of 9.0 points. After production, 60MT:40GT sample had the highest lactic acid bacteria and least total aerobic bacteria counts. Coliform bacteria were absent in all the samples. The nutritional quality of kunun-zaki was improved with groundnut inclusion and the product had high consumer acceptability, showing that the GFK could be a preferred drink for alleviating protein energy malnutrition.
The Brassicaceae family, known as cruciferous vegetables, includes many economic species, mainly edible oil plants, vegetable species, spice plants, and feed plants. Cruciferous vegetables are the foods rich in nutritive composition and are also a good source of dietary fiber. Besides, cruciferous vegetables contain various bioactive chemicals known as glucosinolates and S-methyl cysteine sulfoxide, including sulphur-containing cancer-protective chemicals. Numerous studies have reported that daily intake of sulphurous vegetables helps prevent cancer formation and reduces cancer incidence especially in colorectal cancer through various mechanisms. The potential mechanisms of these compounds in preventing cancer in experimental studies are as follows: protecting cells against DNA damage, inactivating carcinogenic substances, showing antiviral and antibacterial effects, triggering apoptosis in cells with disrupted structure, inhibiting tumour cell migration causing metastasis and the development of tumour-feeding vessels (angiogenesis). These beneficial anticancer effects of cruciferous vegetables are generally associated with glucosinolates in their composition and some secondary metabolites as well as other phenolic compounds, seeds oils and dietary fiber in the literature. This review aims to examine to the roles of cruciferous vegetables and their important bioactive metabolites in the prevention and treatment of colorectal cancer.
Enriched gluten-free products are in high demand owing to increasing celiac disease worldwide. Sourdough fermentation can improve the quality of gluten-free cereals, rendering the resulting product beneficial as a functional food. This study produced sorghum bread (SB) using sourdough technology and evaluated the texture, nutrition profile, bioactive components, and sensory attributes of the product. The base formula was composed of sorghum flour and corn starch. Sourdough made with Pediococcus pentosaceus LD7 (PL7), P. pentosaceus SA8 (PS8), or Weissella confusa SD8 (WS8) was added at a 20% substitution level for bread production, while bread without sourdough addition was used as the control sample. The texture profiles of the SB were significantly (p ˂ 0.05) softer than that of the control. The sourdough breads possessed higher crude protein, ash, and dietary fibre contents than the control bread. Tannin and total phenol contents were significantly (p ˂ 0.05) higher in the sourdough breads compared to the control sample. The specific volume of the sample made with PS8 sourdough was the highest at 2.50 cm3/g compared to the other samples (2.17–2.46 cm3/g). The sourdough samples had higher scores for taste, texture, aroma, and overall acceptability than the control, with PL7 SB exhibiting the best overall acceptability (6.56). This study established promising use of sourdough with starters as an ingredient for baked products with improved technological and nutritional attributes as well as consumer acceptability.
A variety of bacteriocins originate from lactic acid bacteria, which have recently been modified by scientists. Many strains of lactic acid bacteria related to food groups could produce bacteriocins or antibacterial proteins highly effective against foodborne pathogens such as Staphylococcus aureus, Pseudomonas fluorescens, P. aeruginosa, Salmonella typhi, Shigella flexneri, Listeria monocytogenes, Escherichia coli O157:H7, and Clostridium botulinum. A wide range of bacteria belonging primarily to the genera Bifidobacterium and Lactobacillus have been characterized with different health‐promoting attributes. Extensive studies and in‐depth understanding of these antimicrobials mechanisms of action could enable scientists to determine their production in specific probiotic lactic acid bacteria, as they are potentially crucial for the final preservation of functional foods or for medicinal applications. In this review study, the structure, classification, mode of operation, safety, and antibacterial properties of bacteriocins as well as their effect on foodborne pathogens and antibiotic‐resistant bacteria were extensively studied.
Feelings of hunger and satiety are the key determinants for maintaining the life of humans and animals. Disturbed appetite control may disrupt the metabolic health of the host and cause various metabolic disorders. A variety of factors have been implicated in appetite control, including gut microbiota, which develop the intricate interactions to manipulate the metabolic requirements and hedonic feelings. Gut microbial metabolites and components act as appetite-related signaling molecules to regulate appetite-related hormone secretion and the immune system, or act directly on hypothalamic neurons. Herein, we summarize the effects of gut microbiota on host appetite and consider the potential molecular mechanisms. Furthermore, we propose that the manipulation of gut microbiota represents a clinical therapeutic potential for lessening the development and consequence of appetite-related disorders.
Euffm8RKdwQpaRBJkQtTtQVideo abstract
Accumulating evidence indicates that breakdown of the+ protective mucosal barrier of the gut plays a role in colorectal cancer (CRC) development. Inflammation and oxidative stress in the colonic epithelium are thought to be involved in colorectal carcinogenesis and the breakdown of the integrity of the colonic barrier may increase the exposure of colonocytes to toxins from the colonic milieu, enhancing inflammatory processes and release of Reactive Oxygen Species (ROS). The aetiological importance of the gut microbiome and its composition – influenced by consumption of processed meats, red meats and alcoholic drinks, smoking, physical inactivity, obesity - in CRC development is also increasingly being recognized. The gut microbiome has diverse roles, such as in nutrient metabolism and immune modulation. However, microbial encroachment towards the colonic epithelium may promote inflammation and oxidative stress and even translocation of species across the colonic lumen. Recent research suggests that factors that modify the above mechanisms, e.g., obesity and Western diet, also alter gut microbiota, degrade the integrity of the gut protective barrier, and expose colonocytes to toxins. However, it remains unclear how obesity, lifestyle and metabolic factors contribute to gut-barrier integrity, leading to metabolic disturbance, colonocyte damage, and potentially to CRC development. This review will discuss the interactive roles of gut-barrier dysfunction, microbiome dysbiosis, and exposure to endogenous toxins as another mechanism in CRC development, and how biomarkers of colonic mucosal barrier function may provide avenues for disease, prevention and detection.
Background:
Ultra-processed foods are industrial formulations made from food extracts or constituents with little or no intact food and often containing additives that confer hyper-palatability. The consumption of these products increases the risk of chronic non-communicable diseases. Stressed people may engage in unhealthy eating as a way to cope. This study aimed to verify whether ultra-processed food consumption was associated with perceived stress levels in industrial and retail workers from Vitoria da Conquista, Brazil.
Methods:
This was a cross-sectional study carried out between July 2017 and August 2018. During the study period, 1270 participants completed a survey administered by an interviewer. Stress levels were assessed using the Perceived Stress Scale. Information regarding weekly ultra-processed food consumption was collected. Ultra-processed foods were classified into four groups: sugary drinks; sugary foods; fast foods; and canned foods, frozen foods, or processed meat. The Student's t-test or one-way analysis of variance was used to assess the differences in stress levels and ultra-processed food consumption. Ordinal regression was used to determine the association between the degrees of stress and ultra-processed food consumption levels.
Results:
Factors such as a young age, being unmarried, smoking, high-risk alcohol consumption, negative health perception, and high perceived stress level indicated higher rates of ultra-processed food consumption. Ordinal regression analysis showed that high stress levels were associated with increased odds of higher ultra-processed food consumption (odds ratio: 1.94; 95% CI: 1.54-2.45).
Conclusions:
These findings could help identify appropriate target areas for interventions aimed at mental health promotion and healthier food consumption.
Obesity is a chronic disease resulting from an imbalance between energy intake and expenditure. The growing relevance of this metabolic disease lies in its association with other comorbidities. Obesity is a multifaceted disease where intestinal hormones such as cholecystokinin (CCK), glucagon-like peptide 1 (GLP-1), and peptide YY (PYY), produced by enteroendocrine cells (EECs), have a pivotal role as signaling systems. Receptors for these hormones have been identified in the gut and different brain regions, highlighting the interconnection between gut and brain in satiation mechanisms. The intestinal microbiota (IM), directly interacting with EECs, can be modulated by the diet by providing specific nutrients that induce environmental changes in the gut ecosystem. Therefore, macronutrients may trigger the microbiota–gut–brain axis (MGBA) through mechanisms including specific nutrient-sensing receptors in EECs, inducing the secretion of specific hormones that lead to decreased appetite or increased energy expenditure. Designing drugs/functional foods based in bioactive compounds exploiting these nutrient-sensing mechanisms may offer an alternative treatment for obesity and/or associated metabolic diseases. Organ-on-a-chip technology represents a suitable approach to model multi-organ communication that can provide a robust platform for studying the potential of these compounds as modulators of the MGBA.
The gut microbiota resides in the human gastrointestinal tract, where it plays an important role in maintaining host health. Recent advancements in next-generation sequencing methods have revealed the link between dysbiosis (imbalance of the normal gut microbiota) and several diseases, as this imbalance can disrupt the symbiotic relationship between the host and associated microbes. Establishment of the gut microbiota starts in utero or just after birth, and its composition dramatically changes to an adult-like composition by 3 years of age. Because dysbiosis during childhood may persist through adulthood, it is crucial to acquire a balanced gut microbiota in childhood. Therefore, current studies have focused on the factors affecting the infant gut microbiota. This review discusses recent findings, including those from our studies, on how various factors, including the delivery mode, feeding type, and administration of drugs, including antibiotics, can influence the infant gut microbiota. Here, we also address future approaches for the prevention and restoration of dysbiosis in children.
Perturbations of the colonic microbiota can contribute to the initiation and progression of colorectal cancer, leading to an increase in pathogenic bacteria at the expense of protective bacteria. This can contribute to disease through increasing carcinogenic metabolite/toxin production, inducing inflammation, and activating oncogenic signaling. To limit disease progression, external factors that may influence the colonic microbiota need to be considered in patients with colorectal cancer. One major factor that can influence the colonic microbiota is iron. Iron is an essential micronutrient that is required by both prokaryotes and eukaryotes for cellular function. Most pathogenic bacteria have heightened iron acquisition mechanisms and therefore tend to outcompete protective bacteria for free iron. Colorectal cancer patients often present with anemia due to iron deficiency, and thus they require iron therapy. Depending upon the route of administration, iron therapy has the potential to contribute to a procarciongenic microbiota. Orally administered iron is the common treatment for anemia in these patients but can lead to an increased gut iron concentration. This suggests the need to reassess the route of iron therapy in these patients. Currently, this has only been assessed in murine studies, with human trials being necessary to unravel the potential microbial outcomes of iron therapy.
The bioactive ingredients in commonly consumed foods include, but are not limited to, prebiotics, prebiotic‐like components, probiotics, and postbiotics. The bioactive ingredients in functional foods have also been associated with beneficial effects on human health. For example, they aid in shaping of gut microflora and promotion of immunity. These functional components also contribute in preventing serious diseases such as cardiovascular malfunction and tumorigenesis. However, the specific mechanisms of these positive influences on human health are still under investigation. In this review, we aim to emphasize the major contents of probiotics, prebiotics, and prebiotic‐like components commonly found in consumable functional foods, and we present an overview of direct and indirect benefits they provide on human health. The major contributors are certain families of metabolites, specifically short‐chain fatty acids and polyunsaturated fatty acids produced by probiotics, and prebiotics, or prebiotic‐like components such as flavonoids, polyphenols, and vitamins that are found in functional foods. These functional ingredients in foods influence the gut microbiota by stimulating the growth of beneficial microbes and the production of beneficial metabolites that, in turn, have direct benefits to the host, while also providing protection from pathogens and maintaining a balanced gut ecosystem. The complex interactions that arise among functional food ingredients, human physiology, the gut microbiota, and their respective metabolic pathways have been found to minimize several factors that contribute to the incidence of chronic disease, such as inflammation oxidative stress.
The human gut contains trillions of microbes that play a central role in host biology, including the provision of key nutrients from the diet. Food is a major source of precursors for metabolite production; in fact, diet modulates the gut microbiota (GM) as the nutrients, derived from dietary intake, reach the GM, affecting both the ecosystem and microbial metabolic profile. GM metabolic ability has an impact on human nutritional status from childhood. However, there is a wide variability of dietary patterns that exist among individuals. The study of interactions with the host via GM metabolic pathways is an interesting field of research in medicine, as microbiota members produce myriads of molecules with many bioactive properties. Indeed, much evidence has demonstrated the importance of metabolites produced by the bacterial metabolism from foods at the gut level that dynamically participate in various biochemical mechanisms of a cell as a reaction to environmental stimuli. Hence, the GM modulate homeostasis at the gut level, and the alteration in their composition can concur in disease onset or progression, including immunological, inflammatory, and metabolic disorders, as well as cancer. Understanding the gut microbe–nutrient interactions will increase our knowledge of how diet affects host health and disease, thus enabling personalized therapeutics and nutrition.
Background & aims:
The incidence of colorectal cancer (CRC) is increasing in individuals younger than 50 years, who do not usually undergo screening if they are of average risk. We sought to identify risk factors for CRC in this population.
Methods:
We compared sociodemographic and medical characteristics of patients who received a diagnosis of CRC at an age of 18-49 years (early-onset) with patients who received a diagnosis of CRC at an age of 50 years or older (late-onset) and with age-matched, cancer-free individuals (controls) at a tertiary academic hospital. We collected data from all adult patients with a diagnosis of CRC from January 1, 2011 through April 3, 2017 from electronic health records. Associations with risk factors were assessed using univariable and multivariable logistic regression models.
Results:
We identified 269 patients with early-onset CRC, 2802 with late-onset CRC, and 1122 controls. Compared with controls, patients with early-onset CRC were more likely to be male (odds ratio [OR], 1.87; 95% CI, 1.39-2.51), have inflammatory bowel disease (IBD) (3% vs 0.4% for controls; univariable P<.01), and have a family history of CRC (OR, 8.61; CI, 4.83-15.75). Prevalence values of well-established modifiable CRC risk factors, including obesity, smoking, and diabetes, were similar. Compared to patients with late-onset CRC, patients with early-onset CRC were more likely to be male (OR, 1.44; 95% CI, 1.11-1.87), black (OR, 1.73; 95% CI, 1.08-2.65) or Asian (OR, 2.60; 95% CI, 1.57-4.15), and have IBD (OR, 2.97; 95% CI, 1.16-6.63) or a family history of CRC (OR, 2.87; 95% CI, 1.89-4.25). Sensitivity analyses excluding IBD and family history of CRC showed comparable results. Early-onset CRC was more likely than late-onset disease to be detected in the left colon or rectum (75% vs 59%, P=.02) and at a late stage of tumor development (77% vs 62%, P=.01).
Conclusions:
In a retrospective study of patients with early-onset CRC vs late-onset CRC or no cancer, we identified non-modifiable risk factors, including sex, race, IBD, and family history of CRC, to be associated with early-onset CRC.
The gut microbiota is a changing ecosystem, containing trillions of bacteria, continuously shaped by many factors, such as dietary habits, seasonality, lifestyle, stress, antibiotics use, or diseases. A healthy host–microorganisms balance must be respected in order to optimally maintain the intestinal barrier and immune system functions and, consequently, prevent disease development. In the past several decades, the adoption of modern dietary habits has become a growing health concern, as it is strongly associated with obesity and related metabolic diseases, promoting inflammation and both structural and behavioral changes in gut microbiota. In this context, novel dietary strategies are emerging to prevent diseases and maintain health. However, the consequences of these different diets on gut microbiota modulation are still largely unknown, and could potentially lead to alterations of gut microbiota, intestinal barrier, and the immune system. The present review aimed to focus on the impact of single food components (macronutrients and micronutrients), salt, food additives, and different dietary habits (i.e., vegan and vegetarian, gluten-free, ketogenic, high sugar, low FODMAP, Western-type, and Mediterranean diets) on gut microbiota composition in order to define the optimal diet for a healthy modulation of gut microbiota.
The gut microbiome analysis, with specific interest on their direct impact towards the human health, is currently revolutionizing the unexplored frontiers of the pathogenesis and wellness. Although in-depth investigations of gut microbiome, ‘the Black Boxes’, complexities and functionalities are yet at its infancy, profound evidences are being reported for their concurrent involvement in disease etiology and its treatment. Interestingly, studies from the ‘minimal murine’ (Oligo-MM12), ‘humanized’ microbiota gnotobiotic mice models and patient samples, combined with multi-omics and cell biology approaches, have been revealing the implications of these findings in the treatment of gut dysbiosis associated diseases. Nonetheless, due to the inherent heterogeneity of the gut commensals and their unified co-existence with opportunistic pathobionts, it is utmost essential to highlight their functionalities in ‘good or bad’ gut in human wellness. We have specifically reviewed dietary lifestyle and infectious diseases linked with the gut bacterial consortia to delineate the ecobiotic approaches towards their treatment. This notably includes gut mucosal immunity mediated diseases such as Tuberculosis, IBD, CDI, Type 2 Diabetes, etc. Alongside of each dysbiosis, we have described the current therapeutic advancements of the pre- and probiotics derived from human microbiome studies to restore gut microbial homeostasis. With a continuous running debate on the role of microbiota in above mentioned diseases, we have collected numerous scientific evidences highlighting a previously unanticipated complex involvement of gut microbiome in the potential of human health.
The intestinal tract is the largest barrier between a person and the environment. In this role, the intestinal tract is responsible not only for absorbing essential dietary nutrients, but also for protecting the host from a variety of ingested toxins and microbes. The intestinal barrier system is composed of a mucus layer, intestinal epithelial cells (IECs), tight junctions (TJs), immune cells, and a gut microbiota, which are all susceptible to external factors such as dietary fats. When components of this barrier system are disrupted, intestinal permeability to luminal contents increases, which is implicated in intestinal pathologies such as inflammatory bowel disease, necrotizing enterocolitis, and celiac disease. Currently, there is mounting evidence that consumption of excess dietary fats can enhance intestinal permeability differentially. For example, dietary fat modulates the expression and distribution of TJs, stimulates a shift to barrier-disrupting hydrophobic bile acids, and even induces IEC oxidative stress and apoptosis. In addition, a high-fat diet (HFD) enhances intestinal permeability directly by stimulating proinflammatory signaling cascades and indirectly via increasing barrier-disrupting cytokines [TNFα, interleukin (IL) 1B, IL6, and interferon γ (IFNγ)] and decreasing barrier-forming cytokines (IL10, IL17, and IL22). Finally, an HFD negatively modulates the intestinal mucus composition and enriches the gut microflora with barrier-disrupting species. Although further research is necessary to understand the precise role HFDs play in intestinal permeability, current data suggest a stronger link between diet and intestinal disease than was first thought to exist. Therefore, this review seeks to highlight the various ways an HFD disrupts the gut barrier system and its many implications in human health.
The colonic epithelium is exposed to a mixture of compounds through diet, among which some are procarcinogens, whereas others have a protective effect. Therefore, the net impact of these compounds on human health depends on the overall balance between all factors involved. Strong scientific evidence has demonstrated the relationship between nitrosamines (NA), heterocyclic amines (HCAs), and polycyclic aromatic hydrocarbons (PAHs), which are the major genotoxins derived from cooking and food processing, and cancer. The mechanisms of the relationship between dietary toxic xenobiotics and cancer risk are not yet well understood, but it has been suggested that differences in dietary habits affect the colonic environment by increasing or decreasing the exposure to mutagens directly and indirectly through changes in the composition and activity of the gut microbiota. Several changes in the proportions of specific microbial groups have been proposed as risk factors for the development of neoplastic lesions and the enrichment of enterotoxigenic microbial strains in stool. In addition, changes in the gut microbiota composition and activity promoted by diet may modify the faecal genotoxicity/cytotoxicity, which can be associated with a higher or lower risk of developing cancer. Therefore, the interaction between dietary components and intestinal bacteria may be a modifiable factor for the development of colorectal cancer in humans and deserves more attention in the near future.
Colorectal cancer (CRC) is one of the most commonly diagnosed cancers, and it is characterized by genetic and epigenetic alterations, as well as by inflammatory cell infiltration among malignant and stromal cells. However, this dynamic infiltration can be influenced by the microenvironment to promote tumor proliferation, survival and metastasis or cancer inhibition. In particular, the cancer microenvironment metabolites can regulate the inflammatory cells to induce a chronic inflammatory response that can be a predisposing condition for CRC retention. In addition, some nutritional components might contribute to a chronic inflammatory condition by regulating various immune and inflammatory pathways. Besides that, diet strongly modulates the gut microbiota composition, which has a key role in maintaining gut homeostasis and is associated with the modulation of host inflammatory and immune responses. Therefore, diet has a fundamental role in CRC initiation, progression and prevention. In particular, functional foods such as probiotics, prebiotics and symbiotics can have a potentially positive effect on health beyond basic nutrition and have antiinflammatory effects. In this review, we discuss the influence of diet on gut microbiota composition, focusing on its role on gut inflammation and immunity. Finally, we describe the potential benefits of using probiotics and prebiotics to modulate the host inflammatory response, as well as its application in CRC prevention and treatment. © The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
According to GLOBOCAN 2018 data, colorectal cancer (CRC) is the third most deadly and fourth most commonly diagnosed cancer in the world. Nearly 2 million new cases and about 1 million deaths are expected in 2018. CRC incidence has been steadily rising worldwide, especially in developing countries that are adopting the "western" way of life. Obesity, sedentary lifestyle, red meat consumption, alcohol, and tobacco are considered the driving factors behind the growth of CRC. However, recent advances in early detection screenings and treatment options have reduced CRC mortality in developed nations, even in the face of growing incidence. Genetic testing and better family history documentation can enable those with a hereditary predisposition for the neoplasm to take preventive measures. Meanwhile, the general population can reduce their risk by lowering their red meat, alcohol, and tobacco consumption and raising their consumption of fibre, wholesome foods, and certain vitamins and minerals.
There is accumulating evidence that the gut microbiota and its composition dynamics play a crucial role in regulating the host physiological functions and behavior. Diet composition is the primary modulator of bacterial richness and abundance in the gastrointestinal (GI) tract. Macronutrient (fat, sugar and protein) and fiber contents are especially important in determining microbiota composition and its effect on health outcomes and behavior. In addition to food composition, time of intake and eating patterns have recently been shown to significantly affect gut bacterial make up. Diet-driven unfavorable microbiota composition or dysbiosis can lead to an increased production of pro-inflammatory byproducts such as lipopolysaccharide (LPS). Increased inflammatory potential is associated with alteration in gut permeability, resulting in elevated levels of LPS in the bloodstream, or metabolic endotoxemia. We have found that a chronic increase in circulating LPS is sufficient to induce hyperphagia in rodents. Chronic LPS treatment appears to specifically impair the gut-brain axis and vagally-mediated satiety signaling. The vagus nerve relays information on the quantity and quality of nutrients in the GI tract to the nucleus of solitary tract in the brainstem. There is evidence that microbiota dysbiosis is associated with remodeling of the vagal afferent pathway and that normalizing the microbiota composition in high fat diet (HFD) fed rats is sufficient to prevent vagal remodeling. Taken together, these data support a role for the microbiota in regulating gut-brain communication and eating behavior. Bacteria-originating inflammation may play a key role in impairment of diet-driven satiety and the development of hyperphagia.
Colorectal cancer (CRC) is one of the most frequently diagnosed cancers worldwide. Lifestyle is identified as one of the most important risk factors for CRC, especially in sporadic colorectal cancer. The natural composition of the gut microbiota changes rapidly during the first decade of life. Maintaining homeostasis in the gut is essential as structural and metabolic functions of the commensal microbiota inhibit gut colonization of pathogens. Dysbiosis, imbalance in function or structure of gut microbiota, has been associated with a variety of diseases, such as colorectal cancer. The aim of this review was to investigate the possible links between the dysbiosis in gut microbiota and colorectal cancer, and the potential role of anaerobic gut microbiota in the pathogenesis of colorectal cancer. Based on this review, various studies have shown that some of the gut microbiota such as anaerobic bacteria significantly increased in CRC patients, but we suggest more investigations are required to assess the importance of these bacteria and their metabolites in the pathogenesis of CRC are required. ©2018 RIGLD, Research Institute for Gastroenterology and Liver Diseases.
In 2015, the International Agency for Research on Cancer (IARC) indicated that red meat is a probable cause of colon cancer, while processed meat was classified as carcinogenic. The 2010 indicators of lifetime risk for developing colorectal cancer among South African (SA) males and females was 1:114 and 1:182 respectively, while its prevalence as a newly diagnosed cancer was seventh for males and sixth for females. SA consumers have increased their meat expenditure over the past decade as a result of class mobility. This has resulted in an increase in the proportion of middle-class consumers. Although the consumption of red meat has increased, it has been surpassed by chicken. Due to a lack of national food consumption data regarding processed meat, it is not clear what local consumption trends are. The 2015 Consumer Price Index (CPI) documented a significant urban food price increase for chicken, cheaper cuts of beef and polony. However, when comparing urban food prices, a processed meat like polony is 27% cheaper per kilogram than whole chicken. Hence it is possible that the relative affordability of processed meat could contribute to its consumption among many South Africans (SAs) and in so doing, could contribute to colon cancer risk. In relation to the above, it is important for future SA public health recommendations to take cognisance of the World Cancer Research Fund and American Institute for Cancer Research recommendations of limiting red meat consumption to less than 500 g/week and avoiding processed meat.
Nitrate (NO3ˉ) is a metabolic waste produced in humans during the detoxification of nitric oxide (NO). Nitric oxide is responsible for the regulation of blood flow, cell signaling and host defense in a number of mammalian tissues. Shortly after synthesis, nitric oxide is oxidized to nitrate in order to terminate its effect. NO can also be synthesized by an alternative mechanism that relies on the sequential reduction of nitrate to nitrite (NO2ˉ); thereby making nitrite a storage pool that can be reduced to NO under appropriate condition with a concomitant increase in the methemoglobin (metHb) concentration. The NO and metHb produced can result to adverse health effects if not detoxified. NADH-methemoglobin reductase accounts for most metHb reduction. Nitric oxide dioxygenases (NODs) catalyze the conversion of NO to NO3ˉ which help to protect cells from NO poisoning. Nitrate and its reduction products are involved in the modification of the body’s physiological functions. We are exposed to nitrate from dietary intake and nitric oxide oxidation. Nitrate metabolism becomes a threat when nitrate is consumed in excess and the body lacks the enzymes that catalyze the detoxification of its byproducts. During such condition, the hemoglobin, nucleic acids, dietary amines and glycoproteins acts as the primary molecule that mediates its effects. Nitrate is a potential therapeutic agent in the prevention of cardiovascular diseases and improving cell viability. This review serves to reevaluate nitrate metabolism in human with the intentions of understanding its role in NO homeostasis and its metabolic effect due to excess intake.
The health benefits imparted by probiotics and prebiotics as well as synbiotics have been the subject of extensive research in the past few decades. These food supplements termed as functional foods have been demonstrated to alter, modify and reinstate the pre-existing intestinal flora. They also facilitate smooth functions of the intestinal environment. Most commonly used probiotic strains are: Bifidobacterium, Lactobacilli, S. boulardii, B. coagulans. Prebiotics like FOS, GOS, XOS, Inulin; fructans are the most commonly used fibers which when used together with probiotics are termed synbiotics and are able to improve the viability of the probiotics. Present review focuses on composition and roles of Probiotics, Prebiotics and Synbiotics in human health. Furthermore, additional health benefits like immune-modulation, cancer prevention, inflammatory bowel disease etc. are also discussed.
Graphical abstract
Pictorial summary of health benefits imparted by probiotics, prebiotics and synbiotics
Essential oils are constituents synthesized in diverse herb structures as secondary metabolites described as oily aromatic fluids removed from plants. They have been confirmed by the Food and Drug Administration and are considered Generally Recognized as Safe at dosages naturally utilized in foods. Starter cultures are simply a set of microbial preparations used in the processing of foods, one or more microorganisms are added to accelerate the fermentation process of the raw material (milk) into a fermented product. Microbial starter cultures are crucial for achieving consistency in the quality and functional properties of diverse food products. Milk are consumed since immemorial throughout the world; it’s a nutrient-rich liquid that feminine mammals produced to nourish their respective babies. Dairy products are products obtained from milk processing into concentrated as well as easily transportable items with an extended shelf life for instance processed milk, cheese, yogurt, whey, skimmed milk, butter, etc. They are excellent protein and energy sources. The addition of dairy products to human diets adds variety to plant-based diets, which increases the amount and variety of dairy products in the world. According to Bezie and Regasa (2019), fresh milk is the highest dairy product manufactured annually in the world (approximately 32 million tons), next is cheese (about 4 million tons), then yogurt and other fermented milk (3 million tons), butter (almost 1 million tons), and cream (500,000 tons).
Ensuring safe food for consumers is becoming a persistent issue in developing and developed countries. When consumers’ demands and perceptions are not integrated into industrial operations and manufacturing processes, conflicts of interest arise. High society’s expectations have led to intense competition among food producers and industrial investors. However, these contentions should not influence the growers’ and manufacturers’ decision-making in safeguarding the safety of the final food product either raw or processed; because violations of food safety is not only costly to the industry, it also plays a significant role in human lives. This is the primary motivation for implementing specified guidelines in agricultural practices, which helps in the establishment of a balance food chain spanning production to distribution. Good agricultural practices (GAPs) acquaint farmers with the prerequisites for sustainable agricultural approach without jeopardizing the safety of consumers by creating a good consumption and production pattern. Good manufacturing practices are crucial links to all the elements which ensures food’s quality, safety, and efficacy in relation to employees, facilities, environment, process control, and equipment meet up its specifications and purposes. Therefore, to boost consumer-producer understanding and enhance positive dynamism an adaptation and implementation of good agricultural and manufacturing practices is paramount.
Background:
Colorectal cancer (CRC) is the most common gastrointestinal malignancy. And probiotics may have the function of preventing colon cancer. The aim of this study was to investigate the inhibitory effects of a probiotic mixture on colorectal cancer and its potential mechanisms.
Methods:
The effects of the probiotic mixture on proliferation and metastasis of mouse colon cancer CT26 cells were assessed by probiotics and cells co-culture assay, Cell Counting Kit-8 assay, colony formation assay, wound-healing assay, as well as migration and invasion assays. And CT26 cells were also transplanted into BALB/c mice to construct transplanted tumor animal model. The mice were randomly divided into two groups, control group and probiotic mixture intragastric administration group, after injection 21 days the tumor size and infiltration of immune cells in the tumor or spleen tissues were analyzed by hematoxylin and eosin (HE) and immunohistochemistry (IHC) staining.
Results:
The probiotic mixture significantly inhibited the proliferation, invasion, and migration ability of CT26 cells compare to the control cells (P<0.05). In the animal experiments, the tumor volume of mice that had been fed the probiotic mixture was significantly smaller than that of the control group (P<0.05). Compared with control mice, more apoptotic cells and infiltration of immune cells were showed in the tumor tissues of the mice treated with the probiotic mixture, and an increased number of CD8+ cells in the tumor and spleen tissues but no significant change in tissues.
Conclusions:
These results suggested that the probiotic mixture could inhibit the growth of CT26 tumors and induce an immune response in vivo. The probiotic mixture also inhibited the invasion, migration, and proliferation ability of CT26 cells in vitro.
According to recent estimates, over one third of the human population will be diagnosed with cancer at some point in their lifetime. While genetic factors play a large part in cancer risk, as much as 50% of cancers may be preventable through various lifestyle modifications. Nutrition is a major modifiable risk factor, both through its impacts on obesity as well as through dietary chemical exposures that can either increase or decrease cancer risk. However, specific associations and mechanistic links between diet and cancer risk are either inconsistent or elusive. New insights regarding the reciprocal interactions between diet and the gut microbiota, the trillions of organisms that reside in our intestines, may help clarify how diet impacts cancer. The gut microbiota is largely shaped by an individual’s diet and has far-reaching effects on metabolism, the immune system, and inflammation- important factors in the development and progression of various cancers. Likewise, the microbiota modifies dietary components, and consequently, exposure to metabolites that can influence cancer. This review explores some of these diet-microbiota interactions in the context of their potential impacts on cancer prevention.
Fermented milk is an effective carrier for probiotics, whose consumption improves host health. The beneficial effects of probiotics, prebiotics, and synbiotics on gut dysbiosis have been reported previously. However, the way in which specific probiotics, prebiotics, and synbiotics regulate intestinal microbes remains unclear. Therefore, Lactobacillus rhamnosus AS 1.2466 and Lactobacillus delbrueckii ssp. bulgaricus ATCC 11842, xylooligosaccharide, and red ginseng extracts were fed to mice to determine their effects on the intestinal microbiota. Then, mice were administered xylooligosaccharide and L. rhamnosus (synthesis) by gavage, and the number of L. rhamnosus was determined in the intestine at different times. The results show that probiotics and prebiotics can quickly reduce the Firmicutes/Bacteroidetes ratio, inhibit harmful bacteria (such as Klebsiella and Escherichia coli), and accelerate the recovery of beneficial intestinal microorganisms (such as Lactobacillus). In a complex intestinal microecology, different probiotics and prebiotics have different effects on specific intestinal microorganisms that cannot be recovered in the short term. In addition, after 20 d of intragastric xylooligosaccharide addition of 0.12 g/kg of body weight of synbiotics, L. rhamnosus colonization in the mouse ileum was 7.48 log cfu/mL, which was higher than the low-dose group, which could better prolong the colonization time and the number of probiotics in the intestine. Therefore, this study demonstrated that probiotics and prebiotics can promote the balance of intestinal microbiota by regulating specific microbes in the intestine, and the effects of a suitable combination of synbiotics are beneficial, laying the foundation for the development of new dairy products rich in synbiotics.
Background
Dietary factors substantially influence the community structure and function of human gut microbiota. Although many dietary components, such as carbohydrates, fats, proteins and phytochemicals, have been extensively explored for their impact on gut microbiota, little attention has been paid to the influences of various food additives on gut microbiota.
Scope and approach
This review summarizes the current findings on the impact of common food additives on gut microbiota structure and function. The food additives discussed include artificial sweeteners, emulsifiers, preservatives, colorants and acidity regulators. We begin with introduction of gut microbiota and its association with health and disease, and the factors affecting its composition. Then we discuss existing studies on the effects of different types of food additives on the composition and function of gut microbiota. Finally, we present issues that require consideration when interpreting the current findings and highlight the future perspective.
Key findings and conclusion
In vitro studies (such as M-Shime model), animal models (such as mice, rats, pigs and monkeys), and human clinical trials all indicate that different types of food additives could modify gut microbiota and health status. Various models have their own advantages and limitations, therefore cautions need to be taken when the data are interpreted. Considering the ubiquitous use of food additive in processed food, the long-term impact of food additives on gut microbiota needs to be examined in future research. Moreover, whether the changes of specific microbial species caused by food additives could lead to corresponding changes in metabolic and immune functions needs to be further elucidated.
A compilation of volatile N-nitrosamine levels in processed (e.g., cured, canned, smoked) meat and poultry products is presented. Over 1800 samples of processed meat products including bacon, ham, salami, sausage, and various other processed meat and poultry products have been examined for the presence of eight volatile N-nitrosamines. The database compiled from the literature is based on 25 references published for the period of 1985 to 2018 from 14 countries. N-nitrosodimethylamine (NDMA), N-nitrosopiperidine (NPIP), and N-nitrosopyrrolidine (NPYR), are the most frequently identified volatile N-nitrosamines occurring in processed meat and poultry products. N-nitrosodiethylamine (NDEA), and N-nitrosodibutylamine (NDBA) are also frequently observed to a lesser extent. The processed meat and poultry products with the highest levels of volatile N-nitrosamines were pork (fried, fat only eaten), poultry (fried), poultry (spiced, grilled), and bacon (fried).
Colorectal cancer (CRC) incidence changes with time and by variations in diet and lifestyle, as evidenced historically by migrant studies and recently by extensive epidemiologic evidence. The worldwide heterogeneity in CRC incidence is strongly suggestive of etiological involvement of environmental exposures, particularly lifestyle and diet. It is established that physical inactivity, obesity and some dietary factors (red/processed meats, alcohol) are positively associated with CRC, while healthy lifestyle habits show inverse associations. Mechanistic evidence shows that lifestyle and dietary components that contribute to energy excess are linked with increased CRC via metabolic dysfunction, inflammation, oxidative stress, bacterial dysbiosis and breakdown of gut barrier integrity while the reverse is apparent for components associated with decreased risk. This chapter will review the available evidence on lifestyle and dietary factors in CRC etiology and their underlying mechanisms in CRC development. This short review will also touch upon available information on potential gene-environment interactions, molecular sub-types of CRC and anatomical sub-sites within the colorectum.
Since the renaissance of microbiome research in the past decade, much insight has accumulated in comprehending forces shaping the architecture and functionality of resident microorganisms in the human gut. Of the multiple host-endogenous and host-exogenous factors involved, diet emerges as a pivotal determinant of gut microbiota community structure and function. By introducing dietary signals into the nexus between the host and its microbiota, nutrition sustains homeostasis or contributes to disease susceptibility. Herein, we summarize major concepts related to the effect of dietary constituents on the gut microbiota, highlighting chief principles in the diet-microbiota crosstalk. We then discuss the health benefits and detrimental consequences that the interactions between dietary and microbial factors elicit in the host. Finally, we present the promises and challenges that arise when seeking to incorporate microbiome data in dietary planning and portray the anticipated revolution that the field of nutrition is facing upon adopting these novel concepts.
Diet has shaped microbiota profiles through human evolution. Traditional gut microbiomes are described to be driven by high levels of Prevotella. In the present, however, it is consistently described a lower microbial richness in urban industrialized populations compared with individuals living in rural settings, Bacteroides being predominant among urban-industrial gut microbiomes. Components of diet are highly influential in shaping the gut microbiota, being fiber, fat, proteins, polyphenols and micronutrients differentially metabolized by generalist and specialized microorganisms alone or through the phenomenon of cross-feeding. The progressive loss of microbial diversity over generations in industrialized societies along with the emerging increase of chronic non-transmissible diseases have been related to the decline in the consumption of dietary fiber. Diet and derived microbial metabolites have strong implications with the development of food associated diseases such as obesity and metabolic syndrome, malnutrition and eating disorders, intestinal inflammatory diseases and colorectal cancer, among others. Still, there is a need of further studies in order to identify microbiota-related biomarkers of risk for these disorders. In turn, healthy diets and specific nutritional interventions, including increase of dietary fiber and the consumption of probiotics and prebiotics, could be valuable for restoration of beneficial bacteria and microbiota diversity capable to shift from disease to health promoting states.
Background:
Colorectal cancer (CRC) is one of the leading cause of cancer deaths worldwide. Since CRC is largely asymptomatic until alarm features develop to advanced stages, the implementation of the screening programme is very much essential to reduce cancer incidence and mortality rates. CRC occurs predominantly from accumulation of genetic and epigenetic changes in colon epithelial cells, which later gets transformed into adenocarcinomas.
Scope of review:
The current challenges of screening paradigm and diagnostic ranges are from semi-invasive methods like colonoscopy to non-invasive stool-based test, have resulted in over-diagnosis and over-treatment of CRC. Hence, new screening initiatives and deep studies are required for early diagnosis of CRC. In this regard, we not only summarise current predictive and prognostic biomarkers with their potential for diagnostic and therapeutic applications, but also describe current limitations, future perspectives and challenges associated with the progression of CRC.
Major conclusions:
Currently many potential biomarkers have already been successfully translated into clinical practice eg. Fecal haemoglobin, Carcinoembryonic antigen (CEA) and CA19.9, although these are not highly promising diagnostic target for personalized medicine. So there is a critical need for reliable, minimally invasive, highly sensitive and specific genetic markers of an individualised and optimised patient treatment at the earliest disease stage possible.
General significance:
Identification of a new biomarker, or a set of biomarkers to the development of a valid, and clinical sensible assay that can be served as an alternative tool for early diagnosis of CRC and open up promising new targets in therapeutic intervention strategies.
This article reviews the current knowledge of the health effects of dietary fiber and prebiotics and establishes the position of prebiotics within the broader context of dietary fiber. Although the positive health effects of specific fibers on defecation, reduction of postprandial glycemic response, and maintenance of normal blood cholesterol levels are generally accepted, other presumed health benefits of dietary fibers are still debated. There is evidence that specific dietary fibers improve the integrity of the epithelial layer of the intestines, increase the resistance against pathogenic colonization, reduce the risk of developing colorectal cancer, increase mineral absorption, and have a positive impact on the immune system, but these effects are neither generally acknowledged nor completely understood. Many of the latter effects are thought to be particularly elicited by prebiotics. Although the prebiotic concept evolved significantly during the past two decades, the line between prebiotics and nonprebiotic dietary fiber remains vague. Nevertheless, scientific evidence demonstrating the health-promoting potential of prebiotics continues to accumulate and suggests that prebiotic fibers have their rightful place in a healthy diet. Expected final online publication date for the Annual Review of Food Science and Technology Volume 7 is February 28, 2016. Please see http://www.annualreviews.org/catalog/pubdates.aspx for revised estimates.
Meat products can be contaminated with carcinogenic N-nitrosamines, which is ascribed to the reaction between a nitrosating agent, originating from nitrite or smoke, and a secondary amine, derived from protein and lipid degradation. Although in model systems it is demonstrated that many amine containing compounds can be converted to N-nitrosamines, the yield is dependent of reaction conditions (e.g. low pH and high temperature). In this paper the influence of the composition of the meat products (e.g. pH, aw, spices) and processing (e.g. ageing, ripening, fermentation, smoking, heat treatment and storage) on the presence and availability of the amine precursors and the N-nitrosamine formation mechanism is discussed. In addition, this paper explores the current N-nitrosamine mitigation strategies in order to obtain healthier and more natural meat products.
Chronic diarrhea is a frequent symptom among colorectal cancer patients, both during and after treatment for the disease. Chronic diarrhea is the frequent passage of loose stools (>3 unformed stools and/or a volume of stool >200 g in 24 hours) with urgency and duration of more than 4 weeks. Chronic diarrhea can result in metabolic disturbances and poor quality of life. There are many causes, both related and unrelated to the physiological changes with colorectal cancer and its treatment. Patients should be assessed for the underlying cause and adverse outcomes of the chronic diarrhea, including dehydration and electrolyte abnormalities. It is managed with fluid resuscitation, electrolyte repletion, diet modification, and a variety of nonpharmacological and pharmacological interventions. Patients should be referred to gastrointestinal specialists and dietitians for collaborative management. A case study is used to illustrate assessment and management of this symptom.
Due to differences in anatomy, primary rectal and colon cancer require different staging procedures, different neo-adjuvant treatment and different surgical approaches. For example, neoadjuvant radiotherapy or chemoradiotherapy is administered solely for rectal cancer. Neoadjuvant therapy and total mesorectal excision for rectal cancer might be responsible in part for the differing effect of adjuvant systemic treatment on overall survival, which is more evident in colon cancer than in rectal cancer. Apart from anatomic divergences, rectal and colon cancer also differ in their embryological origin and metastatic patterns. Moreover, they harbor a different composition of drug targets, such as v-raf murine sarcoma viral oncogene homolog B (BRAF), which is preferentially mutated in proximal colon cancers, and the epidermal growth factor receptor (EGFR), which is prevalently amplified or overexpressed in distal colorectal cancers. Despite their differences in metastatic pattern, composition of drug targets and earlier local treatment, metastatic rectal and colon cancer are, however, commonly regarded as one entity and are treated alike. In this review, we focused on rectal cancer and its biological and clinical differences and similarities relative to colon cancer. These aspects are crucial because they influence the current staging and treatment of these cancers, and might influence the design of future trials with targeted drugs.
Copyright © 2015. Published by Elsevier Ltd.