Prevention of colorectal cancer and dietary management

In Vitro Antimitotic and Hypoglycemic Effect Study and Acute Toxicity Assessment of the Aqueous and Organic Extracts of Chamaerops humilis L. var. argentea Andre

Background. Chamaerops humilis L. var. argentea Andre is a plant widely spread in the region of Taza (North-East of Morocco); it is used in traditional phytotherapy against cancer, diabetes, inflammations, cardiovascular and respiratory diseases, and for the treatment of digestive disorders. Objective and Methods. The objective of our work is to contribute firstly, to the study of the in vitro antimitotic potential by the phytotest of Lepidium sativum and the evaluation of the in vitro antidiabetic activity of three enzymes (α-amylase, α-glucosidase, and β-galactosidase) on nine aqueous and organic extracts prepared from the leaves of Chamaerops humilis. In addition, a correlation study was carried out on the chemical composition and the antimitotic and antidiabetic activities of Chamaerops humilis leaves. Then, we tested the acute toxicity of the decocted extract and the ethanolic extract. Results. The results of the antimitotic activity showed that the decocted extract showed a higher inhibitory activity than the other aqueous extracts (IC₅₀ = 9.624 × 10³ ± 95.97 μg/mL); for the organic extracts, the ethanolic extract and ethanolic macerated expressed the highest values for the cell growth inhibition test with an IC₅₀ of 5.638 × 10³ ± 22.61 and 5.599 × 10³ ± 45.51 μg/mL with statistically nonsignificant difference. Regarding the antidiabetic activity, the decocted showed a higher inhibitory activity than the other aqueous extracts for α-amylase (IC₅₀ = 1.781 · 10⁵ ± 358.30 μg/mL), α-glucosidase (2.540 × 10² ± 3.14 μg/mL), and β-galactosidase (7.118 × 10² ± 16.13 μg/mL); the ethanolic extract also revealed the highest inhibitory activity for α-amylase (IC₅₀ = 8.902 × 10³ ± 57.81 μg/mL), α-glucosidase (2.216 × 10² ± 1.39 μg/mL), and β-galactosidase (2.003 × 10² ± 7.41 μg/mL). A strong correlation was recorded between the antimitic activity and the inhibitory capacity of β-galactosidase and between these two activities and the chemical composition of Chamaerops humilis leaves. The acute toxicity study showed that the decocted and the ethanolic extract are weakly toxic with an LD₅₀ greater than or equal to 5000 mg/kg. Conclusion. Chamaerops humilis could become a good source in traditional herbal medicine.

Intestinal Microbiota in Colorectal Adenoma-Carcinoma Sequence

Background

Most colorectal cancer (CRC) cases are sporadic and develop along the adenoma-carcinoma sequence. Intestinal microbial dysbiosis is involved in the development of colorectal cancer. However, there are still no absolute markers predicting the progression from adenoma to carcinoma. This study aimed to investigate the characteristics of intestinal microbiota in patients with colorectal adenoma and carcinoma and its correlations with clinical characteristics.

Methods

Fecal samples were collected from 154 patients with CRC, 20 patients with colorectal adenoma (AD) and 199 healthy controls. To analyze the differences in the intestinal microbiota, 16S rRNA gene sequencing was conducted.

Results

At the genus level, there were four significantly different genera among the three groups, namely Acidaminococcus, Alloprevotella, Mycoplasma, and Sphingobacterium, while Acidaminococcus significantly decreased with the order of Control-AD-CRC (P < 0.05). In addition, Parvimonas, Peptostreptococcus, Prevotella, Butyricimonas, Alistipes, and Odoribacter were the key genera in the network of colorectal adenoma/carcinoma-associated bacteria. The top 10 most important species, including Butyricimonas synergistica, Agrobacterium larrymoorei, Bacteroides plebeius, Lachnospiraceae bacterium feline oral taxon 001, Clostridium scindens, Prevotella heparinolytica, bacterium LD2013, Streptococcus mutans, Lachnospiraceae bacterium 19gly4, and Eubacterium hallii, showed the best performance in distinguishing AD from CRC (AUC = 85.54%, 95% CI: 78.83–92.25%). The clinicopathologic features, including age, gender, tumor location, differentiation degree, and TNM stage, were identified to be closely linked to the intestinal microbiome in CRC.

Conclusion

Several intestinal bacteria changed along the adenoma-carcinoma sequence and might be the potential markers for the diagnosis and treatment of colorectal adenoma/carcinoma. Intestinal microbiota characteristics in CRC should account for the host factors.

The association among calorie, macronutrient, and micronutrient intake with colorectal cancer: A case-control study

The risk of colorectal cancer (CRC) can be influenced by dietary components. This study aims to investigate the association between dietary intake and CRC in Iranian adults. This hospital‐based case–control study was performed on 160 patients with CRC and 320 healthy people. General and pathological data were collected through face‐to‐face interviews. A validated food frequency questionnaire (FFQ) was used to assess the intake of calories, macronutrients, and micronutrients. The case group had a significantly higher intake of calories, carbohydrates, vitamin A, vitamin K, fluoride, and molybdenum and a lower intake of vitamin E, vitamin B1, beta carotene, biotin, folate, magnesium, selenium, manganese, and fiber (all p < .001). CRC was positively associated with the intake of carbohydrate (OR: 1.01, CI% 1.03–1.01, p = .001), and vitamin A (OR: 1.009, CI 95% 1.006–1.01, p = .001) and negatively associated with intake of fiber (OR: 0.67, CI 95% 0.59–0.76, p = .001), beta carotene (OR: 0.99, CI 95% 0.99–0.99, p = .001), vitamin E (OR: 0.27, CI 95% 0.15–0.47, p = .001), folate (OR: 0.98 CI 95% 0.97–0.98, p = .001), and biotin (OR: 0.83, CI 95% 0.77–0.90, p = .001). The associations remained significant after adjusting for age and sex. Further adjustments for physical activity, alcohol consumption, and smoking did not change the results. The results identified that the risk of colorectal cancer can be influenced by dietary intake. Further longitudinal studies are needed to confirm these findings and to identify the underlying mechanisms of the effects of dietary components on the risk of colorectal cancer.

Consequences of screening in colorectal cancer (COS-CRC): development and dimensionality of a questionnaire

BACKGROUND

Harms of colorectal cancer (CRC) screening include psychosocial consequences. We have not identified studies using a participant-relevant questionnaire with adequate measurement properties to investigate these harms. However, Brodersen et al. have previously developed a core questionnaire consequences of screening (COS) for use in screening for life-threatening diseases. Therefore, the objectives were: (1) To investigate content validity of COS in a CRC screening setting and in case of gaps in content coverage (2) generate new items and themes and (3) test the possibly extended version of COS for dimensionality and differential item functioning (DIF) using Rasch Models.

METHODS

We performed two-part-focus-groups with CRC screenees. Screenees were recruited by strategic sampling. In the first part 16 screenees with false-positive results (n = 7) and low-risk polyps (n = 9) were interviewed about their CRC screening experiences and in the second part COS was examined for content validity. When new information was developed in the focus groups, new items covering this topic were generated. Subsequently, new items were, together with COS, tested in the subsequent interviews. A random subsample (n = 410) from a longitudinal questionnaire study, not yet published, was used to form the data for this paper. We analysed multidimensionality and uniform DIF with Andersen's conditional likelihood ratio test. We assessed individual item fit to the model. We also analysed Local Dependence (LD) and DIF by partial gamma coefficients using Rasch Models.

RESULTS

COS was found relevant in a CRC screening setting. However, new information was discovered in the focus groups, covered by 18 new CRC screening-specific items. The Rasch analyses only revealed minor problems in the COS-scales. The 18 new items were distributed on four new CRC screening-specific dimensions and one single item.

CONCLUSION

An extended version of COS specifically for use in a CRC screening setting has been developed. The extended part encompasses four new scales and one new single item. The original COS with the CRC-screening specific extension is called consequences of screening in colorectal cancer (COS-CRC). COS-CRC possessed reliability, unidimensionality and invariant measurement.

Gut Microbiota and Colorectal Cancer Development: A Closer Look to the Adenoma-Carcinoma Sequence

There is wide evidence that CRC could be prevented by regular physical activity, keeping a healthy body weight, and following a healthy and balanced diet. Many sporadic CRCs develop via the traditional adenoma-carcinoma pathway, starting as premalignant lesions represented by conventional, tubular or tubulovillous adenomas. The gut bacteria play a crucial role in regulating the host metabolism and also contribute to preserve intestinal barrier function and an effective immune response against pathogen colonization. The microbiota composition is different among people, and is conditioned by many environmental factors, such as diet, chemical exposure, and the use of antibiotic or other medication. The gut microbiota could be directly involved in the development of colorectal adenomas and the subsequent progression to CRC. Specific gut bacteria, such as Fusobacterium nucleatum, Escherichia coli, and enterotoxigenic Bacteroides fragilis, could be involved in colorectal carcinogenesis. Potential mechanisms of CRC progression may include DNA damage, promotion of chronic inflammation, and release of bioactive carcinogenic metabolites. The aim of this review was to summarize the current knowledge on the role of the gut microbiota in the development of CRC, and discuss major mechanisms of microbiota-related progression of the adenoma-carcinoma sequence.

Role of Vitamin D in Colorectal Cancer: A Holistic Approach and Review of the Clinical Utility

Vitamin D is well known for its effects on the homeostasis of calcium and phosphorus. Lately, considerable research has brought the extra-skeletal role of vitamin D under the spotlight, including its anti-cancer activity. Colorectal cancer (CRC) is the most extensively studied neoplasia that has been observed to be affected by vitamin D; the list includes breast, prostate, and ovarian cancer. This review aims to shine a light on the influence of vitamin D over CRC and to further understand its ability to be used as a potential economical treatment for CRC patients. For this review, PubMed was used as the main database for the literature search. Studies on the role of vitamin D on CRC within 10 years and all of the study types were included. Post the extensive research over PubMed, it was noted that vitamin D, through its effect on multiple pathways, especially Wnt/β-catenin, apoptosis, and inflammation, hinders the progression of CRC carcinogenesis. High levels of this steroid hormone can delay the progression and may provide a cost-effective way of treating CRC patients. Further research and additional human trials are still due to bring about more knowledge on this topic. In conclusion, high serum levels of vitamin D are associated with a lower risk of incidence and progression of CRC.

Dietary Intake of N-3 and N-6 Polyunsaturated Fatty Acids and Risk of Cancer: Meta-Analysis of Data from 32 Studies

BACKGROUND

Large epidemiological studies have yielded conflicting results regarding the relationship between polyunsaturated fatty acids (PUFAs) and cancers. Here, we performed a meta-analysis to examine the link between dietary intake of n-3 and n-6 PUFAs and cancer risk.

MATERIALS AND METHODS

We performed a search on PubMed, EMBASE, and the Cochrane Library. Studies that reported adjusted relative risk (RR) estimates with 95% confidence intervals (CI) for the associations of interest were included.

RESULTS

Thirty-two studies involving 1,445,732 participants were included. Colorectal, breast and prostate cancer had been analyzed in our study. Specifically, for colorectal cancer, total n-3 PUFAs, marine n-3 PUFAs, α-linolenic acids (ALA) and n-6 PUFAs were not associated with the risk of it (RR 1.04, 95%CI 0.85-1.28; RR 0.99, 95%CI 0.89-1.09; RR 1.05, 95%CI 0.93-1.19; RR 1.02, 95%CI 0.94-1.11, respectively). For breast cancer, only marine n-3 PUFAs, but not total n-3 PUFAs, ALA, and n-6 PUFAs, was associated with a lower risk of it (RR 0.70, 95%CI 0.55-0.91). For prostate cancer, ALA and n-6 PUFAs also have no association with the risk of it.

CONCLUSIONS

Most subtypes of PUFAs are probably not related to cancers. However, additional high-quality trials are warranted to corroborate the findings of this meta-analysis.

Bioactive molecules of probiotic bacteria and their mechanism of action: a review

The bacteria residing in the gut environment do play a pivotal role in metabolic activities of the host. The metabolites produced by these bacteria affect the physiology and health of the host. The gut bacteria are exposed to environmental conditions where multiple factors such as lifestyle, stress, antibiotics, host genetics and infections have an influence on them. In case of pathogenesis of a disease, the gut bacterial composition is altered which leads to a diseased state. This stage is due to colonization of bacterial pathogens in the gut environment. The pathological condition can be alleviated by administering probiotic strains into the gut environment. The probiotic strains produce therapeutic molecules such as amino acids, vitamins, bacteriocins, enzymes, immunomodulatory compounds and short-chain fatty acids. This review discusses recent evidences of the impact of bioactive molecules produced by probiotic bacteria and their mechanism of action in the gut environment to maintain homeostasis and health of the host without any effect on beneficial bacteria sharing the same niche. In addition, the manufacturing challenges of probiotic products for various applications are discussed here.

"Dietary fibre": moving beyond the "soluble/insoluble" classification for monogastric nutrition, with an emphasis on humans and pigs

This review describes dietary fibres originating from a range of foods, particularly in relation to their plant cell walls. It explores the categorization of dietary fibres into “soluble” or “insoluble”. It also emphasizes dietary fibre fermentability, in terms of describing how the gastro-intestinal tract (GIT) microbiota respond to a selection of fibres from these categories. Food is categorized into cereals, legumes, fruits and vegetables. Mention is also made of example whole foods and why differences in physico-chemical characteristics between “purified” and “non-purified” food components are important in terms of health. Lastly, recommendations are made as to how dietary fibre could be classified differently, in relation to its functionality in terms of fermentability, rather than only its solubility.

Effect of dietary components on miRNA and colorectal carcinogenesis

Background

Colorectal cancer (CRC) is one of the most common cancers diagnosed and among the commonest causes of cancer-related mortality globally. Despite the various available treatment options, millions of people still suffer from this illness and most of these treatment options have several limitations. Therefore, a less expensive, non-invasive or a treatment that requires the use of dietary products remains a focal point in this review.

Main body

Aberrant microRNA expression has been revealed to have a functional role in the initiation and progression of CRC. These has shown significant promise in the diagnosis and prognosis of CRC, owing to their unique expression profile associated with cancer types and malignancies. Moreover, microRNA therapeutics show a great promise in preclinical studies, and these encourage further development of their clinical use in CRC patients. Additionally, emerging studies show the chemo-preventive potential of dietary components in microRNA modulation using several CRC models. This review examines the dietary interplay between microRNAs and CRC incidence. Improving the understanding of the interactions between microRNAs and dietary components in the carcinogenesis of CRC will assist the study of CRC progression and finally, in developing personalized approaches for cancer prevention and therapy.

Conclusion

Although miRNA research is still at its infancy, it could serve as a promising predictive biomarkers and therapeutic targets for CRC. Given the ever-expanding number of miRNAs, understanding their functional aspects represents a promising option for further research.

Gut Fermentation of Dietary Fibres: Physico-Chemistry of Plant Cell Walls and Implications for Health

The majority of dietary fibre (DF) originates from plant cell walls. Chemically, DF mostly comprise carbohydrate polymers, which resist hydrolysis by digestive enzymes in the mammalian small intestine, but can be fermented by large intestinal bacteria. One of the main benefits of DF relate to its fermentability, which affects microbial diversity and function within the gastro-intestinal tract (GIT), as well as the by-products of the fermentation process. Much work examining DF tends to focus on various purified ingredients, which have been extracted from plants. Increasingly, the validity of this is being questioned in terms of human nutrition, as there is evidence to suggest that it is the actual complexity of DF which affects the complexity of the GIT microbiota. Here, we review the literature comparing results of fermentation of purified DF substrates, with whole plant foods. There are strong indications that the more complex and varied the diet (and its ingredients), the more complex and varied the GIT microbiota is likely to be. Therefore, it is proposed that as the DF fermentability resulting from this complex microbial population has such profound effects on human health in relation to diet, it would be appropriate to include DF fermentability in its characterization-a functional approach of immediate relevance to nutrition.

Addition of arabinoxylan and mixed linkage glucans in porcine diets affects the large intestinal bacterial populations

PURPOSE

To investigate the effects of two cereal soluble dietary fibres (SDF), wheat arabinoxylan (AX) and oat-mixed linkage glucans (MLG), on fermentative end-products and bacterial community profiles of the porcine caecum (Cae) and distal colon (DC). We hypothesised that feeding pigs these SDF would stimulate Cae and DC carbohydrate fermentation, resulting in a modification of the resident bacterial communities.

METHODS

Five groups of six pigs were each fed one diet based on wheat starch (WS) only, or treatment diets in which some WS was replaced by 10 % AX, or 10 % MLG, a combination of 5 % AX:5 % MLG (AXMLG), or completely replaced with ground whole wheat. Post-euthanasia, Cae and DC digesta were collected for analysis of fermentative end-products, and bacterial community profiles were determined by 16S rRNA gene amplicon 454 pyrosequencing.

RESULTS

Across all the SDF-containing diets, predominantly in the proximal region of the large intestine, Prevotella, Lactobacillus, Mitsuokella and Streptococcus were most significantly influenced (P < 0.05), while notable changes were observed for the Ruminococcaceae and Lachnospiraceae families in the Cae and DC. The addition of MLG or AXMLG had the greatest effect of influencing bacterial profiles, reducing sequence proportions assigned to the genus Clostridium, considered detrimental to gut health, with associated increases in short-chain fatty acid and reduced ammonia concentrations.

CONCLUSIONS

This study demonstrated how the cereal SDF AX and MLG altered the large intestinal bacterial community composition, particularly proximally, further giving insights into how diets rich in specific complex carbohydrates shift the bacterial population, by increasing abundance and promoting greater diversity of those bacteria considered beneficial to gut health.

Folate status, folate-related genes and serum miR-21 expression: Implications for miR-21 as a biomarker

BACKGROUND

Free circulating microRNA (miRNA) in serum may be valuable biomarkers for disease diagnosis and prognosis. miR-21, the archetypal oncogenic miRNA, has been proposed as a biomarker for colorectal cancer and its benign precursor, adenomatous polyps. However, it is now becoming clear that circulating miRNA profiles may be sensitive to lifestyle and environmental influences. Dietary components involved in one-carbon metabolism are particularly well placed to modulate miRNA expression through an influence on DNA methylation pathways.

METHODS

We investigated the role of methyl group donors (folate, B12, cysteine, homocysteine), polymorphisms of the enzymes of one-carbon metabolism, and serum miR-21 expression in a primary case-control cohort (colonoscopy confirmed adenomatous colon polyps vs controls; n = 253) and a secondary cross-sectional cohort (over 65s; n = 649). The relationships between these parameters and serum miR-21 levels were assessed, stratified by gender.

CONCLUSIONS

Serum miR-21 expression was related to occurrence of adenomatous polyps in females, but not males. Folate levels and MTHFR-C677T genotype was associated with miR-21 expression in both genders. Additionally, DHFR-19 del and MSR-A66G were associated with miR-21 expression in females and males, respectively. Stimulation with excess folate increased expression of miR-21 in colon cancer cell lines.

GENERAL SIGNIFICANCE

This study demonstrates that serum miR-21 expression correlates with folate status and related genetic status. This may have consequences for the proposed use of miR-21 as a colorectal cancer biomarker.

Diagnosis and management of acute complications in patients with colon cancer: bleeding, obstruction, and perforation

Among the colorectal cancers, the incidence of colon cancer has obviously increased. As a result, the actual incidence of colon cancer has exceeded that of rectal cancer, which dramatically changed the long-existing epidemiological profile. The acute complications of colon cancer include bleeding, obstruction, and perforation, which were among the common acute abdominal surgical conditions. The rapid and accurate diagnosis of these acute complications was very important, and laparoscopic techniques can be applied in abdominal surgery for management of the complications.