Milk and risk of colorectal, colon and rectal cancer in the Norwegian Women and Cancer (NOWAC) Cohort Study

Dietary patterns, untargeted metabolite profiles and their association with colorectal cancer risk

We investigated data-driven and hypothesis-driven dietary patterns and their association to plasma metabolite profiles and subsequent colorectal cancer (CRC) risk in 680 CRC cases and individually matched controls. Dietary patterns were identified from combined exploratory/confirmatory factor analysis. We assessed association to LC-MS metabolic profiles by random forest regression and to CRC risk by multivariable conditional logistic regression. Principal component analysis was used on metabolite features selected to reflect dietary exposures. Component scores were associated to CRC risk and dietary exposures using partial Spearman correlation. We identified 12 data-driven dietary patterns, of which a breakfast food pattern showed an inverse association with CRC risk (OR per standard deviation increase 0.89, 95% CI 0.80-1.00, p = 0.04). This pattern was also inversely associated with risk of distal colon cancer (0.75, 0.61-0.96, p = 0.01) and was more pronounced in women (0.69, 0.49-0.96, p = 0.03). Associations between meat, fast-food, fruit soup/rice patterns and CRC risk were modified by tumor location in women. Alcohol as well as fruit and vegetables associated with metabolite profiles (Q2 0.22 and 0.26, respectively). One metabolite reflecting alcohol intake associated with increased CRC risk, whereas three metabolites reflecting fiber, wholegrain, and fruit and vegetables associated with decreased CRC risk.

Pre-diagnostic intake of vitamin D and incidence of colorectal cancer by anatomical subsites: the Norwegian Women and Cancer Cohort Study (NOWAC)

According to the World Cancer Research Fund International, vitamin D might decrease the risk of colorectal cancer (CRC). However, less is known about the association with cancers in different subsites of the colon and in the rectum. The aim of this study was to examine associations between pre-diagnostic intake of vitamin D and risk of CRC by anatomical subsites. Data from 95 416 participants in the Norwegian Women and Cancer Cohort Study was included, and vitamin D intake was estimated from two repeated FFQ. Associations between vitamin D intake and incidence of CRC were assessed using multivariable Cox regression. During follow-up, there were 1774 incident cases of CRC. A small but borderline significant inverse association was found for a 5-µg increase in vitamin D intake and risk of CRC (hazard ratio (HR) = 0·97; 95 % CI 0·93, 1·01) and colon cancer (HR = 0·96; 95 % CI 0·91, 1·01). High (≥ 20 µg) compared with low (< 10 µg) vitamin D intake was associated with 17 % borderline significant reduced risk of CRC (HR = 0·83; 95 % CI 0·68, 1·02). Medium (10-19 µg) v. low intake (< 10 µg) was associated with 27 % reduced risk of proximal colon cancer (HR = 0·73; 95 % CI 0·57, 0·94). No significant associations were observed between vitamin D intake and risk of distal colon or rectal cancer. Our study indicates that vitamin D may be differently associated with subsites of the colon. The association between vitamin D intake and proximal colon cancer is novel.

Potential Pathogenic Impact of Cow’s Milk Consumption and Bovine Milk-Derived Exosomal MicroRNAs in Diffuse Large B-Cell Lymphoma

Epidemiological evidence supports an association between cow’s milk consumption and the risk of diffuse large B-cell lymphoma (DLBCL), the most common non-Hodgkin lymphoma worldwide. This narrative review intends to elucidate the potential impact of milk-related agents, predominantly milk-derived exosomes (MDEs) and their microRNAs (miRs) in lymphomagenesis. Upregulation of PI3K-AKT-mTORC1 signaling is a common feature of DLBCL. Increased expression of B cell lymphoma 6 (BCL6) and suppression of B lymphocyte-induced maturation protein 1 (BLIMP1)/PR domain-containing protein 1 (PRDM1) are crucial pathological deviations in DLBCL. Translational evidence indicates that during the breastfeeding period, human MDE miRs support B cell proliferation via epigenetic upregulation of BCL6 (via miR-148a-3p-mediated suppression of DNA methyltransferase 1 (DNMT1) and miR-155-5p/miR-29b-5p-mediated suppression of activation-induced cytidine deaminase (AICDA) and suppression of BLIMP1 (via MDE let-7-5p/miR-125b-5p-targeting of PRDM1). After weaning with the physiological termination of MDE miR signaling, the infant’s BCL6 expression and B cell proliferation declines, whereas BLIMP1-mediated B cell maturation for adequate own antibody production rises. Because human and bovine MDE miRs share identical nucleotide sequences, the consumption of pasteurized cow’s milk in adults with the continued transfer of bioactive bovine MDE miRs may de-differentiate B cells back to the neonatal “proliferation-dominated” B cell phenotype maintaining an increased BLC6/BLIMP1 ratio. Persistent milk-induced epigenetic dysregulation of BCL6 and BLIMP1 expression may thus represent a novel driving mechanism in B cell lymphomagenesis. Bovine MDEs and their miR cargo have to be considered potential pathogens that should be removed from the human food chain.

Association between Diet-related Behaviour and Risk of Colorectal Cancer: A Scoping Review

Individual dietary patterns may be influenced by diet-related behaviours, which may eventually play a significant role in contributing to colorectal cancer risk. As nearly half of colorectal cancer cases can be prevented through diet and lifestyle modification, in this study, we aimed to present an overview of the literature on diet-related behaviour and its effect on colorectal cancer risk among adults. Articles published from 2011 until July 2021 were selected. Out of the 1,198 articles retrieved, 25 were analyzed. There were 16 case-control studies, and nine of them were cohort studies. As a finding, the instruments used in this review were food frequency questionnaires (n = 23), followed by a semi-structured interview (n = 1), and diet records (n = 1). We demonstrated that unhealthy diet-related behaviours are linked to an increased risk of colorectal cancer in adults and those food frequency questionnaires or food records are common instruments used to collect diet-related behaviours. This article imparts the research trends and directions of colorectal cancer risk factors and shows that diet-related behaviour varies and changes over time.

Microbe-based therapies for colorectal cancer: Advantages and limitations

Cancer is one of the leading global causes of death in both men and women. Colorectal cancer (CRC) alone accounts for ∼10 % of total new global cases and poses an over 4% lifetime risk of developing cancer. Recent advancements in the field of biotechnology and microbiology concocted novel microbe-based therapies to treat various cancers, including CRC. Microbes have been explored for human use since centuries, especially for the treatment of various ailments. The utility of microbes in cancer therapeutics is widely explored, and various bacteria, fungi, and viruses are currently in use for the development of cancer therapeutics. The human gut hosts about 100 trillion microbes that release their metabolites in active, inactive, or dead conditions. Microbial secondary metabolites, proteins, immunotoxins, and enzymes are used to target cancer cells to induce cell cycle arrest, apoptosis, and death. Various approaches, such as dietary interventions, the use of prebiotics and probiotics, and fecal microbiota transplantation have been used to modulate the gut microbiota in order to prevent or treat CRC pathogenesis. The present review highlights the role of the gut microbiota in CRC precipitation, the potential mechanisms and use of microorganisms as CRC biomarkers, and strategies to modulate microbiota for the prevention and treatment of CRC.

Role of Dairy Foods, Fish, White Meat, and Eggs in the Prevention of Colorectal Cancer: A Systematic Review of Observational Studies in 2018-2022

There is limited evidence to support the relationship between the consumption of animal-source foods other than red meat and processed meat and colorectal cancer (CRC) risk. We aimed to examine the recent available evidence from observational studies about the association between these food groups’ intake and CRC risk. For this systematic review, we searched the PubMed database for the last five years. A total of fourteen cohort studies and seven case−control studies comprising a total of >60,000 cases were included. The studies showed a consistent significant decrease in CRC risk, overall and by subsites, associated with a high consumption of total dairy products. Less strong effects associated with the consumption of any subtype of dairy product were observed. Fish consumption, overall and by subtypes (oily or non-oily and fresh or canned), showed a mild inverse association with CRC risk. The association between white meat and egg intake and CRC risk was low and based on a small number of studies; thus, these findings should be interpreted with caution. In conclusion, a high consumption of total dairy products was associated with a lower CRC risk. However, evidence for fish, white meat, and eggs and the CRC risk were not as strong.

Enhancement of Anti-Tumoral Immunity by β-Casomorphin-7 Inhibits Cancer Development and Metastasis of Colorectal Cancer

β-Casomorphin-7 (BCM) is a degradation product of β-casein, a milk component, and has been suggested to affect the immune system. However, its effect on mucosal immunity, especially anti-tumor immunity, in cancer-bearing individuals is not clear. We investigated the effects of BCM on lymphocytes using an in vitro system comprising mouse splenocytes, a mouse colorectal carcinogenesis model, and a mouse orthotopic colorectal cancer model. Treatment of mouse splenocytes with BCM in vitro reduced numbers of cluster of differentiation (CD) 20⁺ B cells, CD4⁺ T cells, and regulatory T cells (Tregs), and increased CD8⁺ T cells. Administration of BCM and the CD10 inhibitor thiorphan (TOP) to mice resulted in similar alterations in the lymphocyte subsets in the spleen and intestinal mucosa. BCM was degraded in a concentration- and time-dependent manner by the neutral endopeptidase CD10, and the formed BCM degradation product did not affect the lymphocyte counts. Furthermore, degradation was completely suppressed by TOP. In the azoxymethane mouse colorectal carcinogenesis model, the incidence of aberrant crypt foci, adenoma, and adenocarcinoma was reduced by co-treatment with BCM and TOP. Furthermore, when CT26 mouse colon cancer cells were inoculated into the cecum of syngeneic BALB/c mice and concurrently treated with BCM and TOP, infiltration of CD8⁺ T cells was promoted, and tumor growth and liver metastasis were suppressed. These results suggest that by suppressing the BCM degradation system, the anti-tumor effect of BCM is enhanced and it can suppress the development and progression of colorectal cancer.

Transcriptome Profiling and Metagenomic Analysis Help to Elucidate Interactions in an Inflammation-Associated Cancer Mouse Model

Simple Summary

Colitis-associated colorectal cancer is the third most significant condition that increases the overall risk of developing colorectal cancer. In this study, we examined normal colonic mucosa of tumor-bearing mice in the DSS/AOM mouse model by gene expression profiling and fecal samples by 16s rDNA amplicon sequencing. Gene set enrichment analysis revealed that genes associated with fatty acid metabolism, oxidative phosphorylation, and the PI3K-Akt-mTOR pathways were enriched colonic mucosa of DSS/AOM mice. Additionally, enrichment of the sphingolipid signal and lipoarabinomannan biosynthetic pathways were inferred from fecal microbial composition. Our findings provide insights into altered transcriptome and microbiome in a mouse model of colitis-induced carcinogenesis.

Abstract

Colitis is a risk factor for colorectal cancer (CRC) and can change the dynamics of gut microbiota, leading to dysbiosis and contributing to carcinogenesis. The functional interactions between colitis-associated CRC and microbiota remain unknown. In this study, colitis and CRC were induced in BALB/c mice by the administration of dextran sodium sulfate (DSS) and/or azoxymethane (AOM). Whole transcriptome profiling of normal colon was then performed, and gene set enrichment analysis (GSEA) revealed enriched fatty acid metabolism, oxidative phosphorylation, and PI3K-Akt-mTOR signaling in the tissues from DSS/AOM mice. Additionally, immunohistochemical staining showed increased expression levels of phosphorylated S6 ribosomal protein, a downstream target of the PI3K-Akt-mTOR pathway in the inflamed mucosa of DSS/AOM mice. Fecal microbes were characterized using 16S rDNA gene sequencing. Redundancy analysis demonstrated a significant dissimilarity between the DSS/AOM group and the others. Functional analysis inferred from microbial composition showed enrichments of the sphingolipid signal and lipoarabinomannan biosynthetic pathways. This study provides additional insights into alterations associated with DSS/AOM-induced colitis and associates PI3K-Akt-mTOR, sphingolipid-signaling and lipoarabinomannan biosynthetic pathways in mouse DSS/AOM-induced colitis.

Soybean-derived gma-miR159a alleviates colon tumorigenesis by suppressing TCF7/MYC in mice

Previous reports have shown that plant-derived microRNAs (miRNAs) regulate mammalian gene expression through dietary intake. Our prior study found that gma-miR159a, which is abundant in soybean, significantly inhibited the proliferation of colon cancer cells. In the current study, dietary gma-miR159a was utilized to study its anti-colon cancer function in azoxymethane (AOM)/dextran sodium sulfate (DSS)-induced colon cancer mice. Under processing conditions, gma-miR159a exhibited excellent stability in cooked soybean. In vitro, gma-miR159a suppressed the expression of the oncogene MYC downstream of the Wnt signaling pathway by targeting the TCF7 gene, significantly inhibiting the growth of colon cancer cells. The in vivo experiments showed that gma-miR159a and soybean RNA (total RNA extracted from soybean) significantly reduced tumor growth in AOM/DSS-induced colon cancer mice by gavage. This effect disappeared when anti-miR159a was present. In addition, gma-miR159a and soybean RNA significantly attenuated inflammation in colon cancer mice. These results showed that long-term dietary intake of soybean-derived gma-miR159a effectively prevented the occurrence of colon cancer and colitis, which provides novel evidence for the prevention function of soybean.

The alterations of microbiota and pathological conditions in the gut of patients with colorectal cancer undergoing chemotherapy

Colorectal cancer (CRC) has become a serious threat to human life and health. Most patients are diagnosed at the late stage of advanced CRC, resulting in losing their best opportunity for surgical treatment. Chemotherapy plays a crucial role in the control and treatment of advanced CRC. However, the cytotoxicity of chemotherapeutic drugs can easily cause the imbalance of gut flora, damage the barrier of the gastrointestinal mucosa, and mediate mucosal inflammation of the digestive tract, which is called "gastrointestinal mucositis." This mucositis can affect the quality of life of the host and even threaten their lives. Several studies reported the association between chemotherapy-mediated gastrointestinal mucositis in CRC and gut dysbiosis. However, the underlying mechanisms of this association are still unclear. The alternative or complementary treatments to reshape gut microbiota and slow down the side effects of chemotherapy have shown the improvement of gastrointestinal mucositis following chemotherapy in the CRC condition. This review will summarize and discuss the evidence of the association between chemotherapy-mediated gastrointestinal mucositis in CRC and altered gut microbiota from in vivo and clinical studies. The possible mechanisms of gastrointestinal mucositis, including the destruction of the gastrointestinal mucosal barrier, the induction of gut dysbiosis, and histopathological changes in the gut of CRC with chemotherapy will be illustrated. In addition, the nonpharmacological interventions and phytochemical extracts by using the manipulation of the microbial population for therapeutic purposes for relieving side effects of chemotherapy as well as a cancer treatment would be summarized and discussed in this review.

Milk consumption and multiple health outcomes: umbrella review of systematic reviews and meta-analyses in humans

In order to recapitulate the best available evidence of milk consumption and multiple health-related outcomes, we performed an umbrella review of meta-analyses and systematic reviews in humans. Totally, 41 meta-analyses with 45 unique health outcomes were included. Milk consumption was more often related to benefits than harm to a sequence of health-related outcomes. Dose–response analyses indicated that an increment of 200 ml (approximately 1 cup) milk intake per day was associated with a lower risk of cardiovascular disease, stroke, hypertension, colorectal cancer, metabolic syndrome, obesity and osteoporosis. Beneficial associations were also found for type 2 diabetes mellitus and Alzheimer's disease. Conversely, milk intake might be associated with higher risk of prostate cancer, Parkinson’s disease, acne and Fe-deficiency anaemia in infancy. Potential allergy or lactose intolerance need for caution. Milk consumption does more good than harm for human health in this umbrella review. Our results support milk consumption as part of a healthy diet. More well-designed randomized controlled trials are warranted.

ROS-Mediated Apoptotic Cell Death of Human Colon Cancer LoVo Cells by Milk δ-Valerobetaine

δ-Valerobetaine (δVB) is a constitutive milk metabolite with antioxidant and anti-inflammatory activities. Here, we tested the antineoplastic properties of milk δVB on human colorectal cancer cells. CCD 841 CoN (non-tumorigenic), HT-29 (p53 mutant adenocarcinoma) and LoVo (APC/RAS mutant adenocarcinoma) cells were exposed to 3 kDa milk extract, δVB (2 mM) or milk+δVB up to 72 h. Results showed a time- and dose-dependent capability of δVB to inhibit cancer cell viability, with higher potency in LoVo cells. Treatment with milk+δVB arrested cell cycle in G2/M and SubG1 phases by upregulating p21, cyclin A, cyclin B1 and p53 protein expressions. Noteworthy, δVB also increased necrosis (P < 0.01) and when used in combination with milk it improved its activity on live cell reduction (P < 0.05) and necrosis (P < 0.05). δVB-enriched milk activated caspase 3, caspase 9, Bax/Bcl-2 apoptotic pathway and reactive oxygen species (ROS) production, whereas no effects on ROS generation were observed in CCD 841 CoN cells. The altered redox homeostasis induced by milk+δVB was accompanied by upregulation of sirtuin 6 (SIRT6). SIRT6 silencing by small interfering RNA blocked autophagy and apoptosis activated by milk+δVB, unveiling the role of this sirtuin in the ROS-mediated apoptotic LoVo cell death.

Effects of fucoidan on gut flora and tumor prevention in 1,2-dimethylhydrazine-induced colorectal carcinogenesis

Colorectal cancer (CRC) is one of the major malignancies in humans. This study was designed to evaluate the effects of fucoidan on gut flora and tumor prevention in 1,2-dimethylhydrazine-induced colorectal carcinogenesis in rats. We found that dietary fucoidan treatment decreased the tumor incidence and mean tumor weight and increased cell apoptosis. Fucoidan treatment decreased the expression of β-catenin C-Myc, CyclinD1 and Survivin, while the Hippo pathway was activated with increased phosphorylation levels of mammalian sterile 20-like kinase 1 and 2, large tumor suppressor 1 and 2, and Yes-associated protein. Compared with the model group, the levels of interleukin (IL)-17 and IL-23 were decreased, but the levels of interferon-γ, IL-4 and IL-10 were increased, in the fucoidan group. Fucoidan treatment increased natural killer cells in peripheral blood and the proportion of CD4+ T cells. Immunofluorescence detection of colorectal tumor tissues showed decreased expression of Foxp3 and up-regulated expression of CD68 in the fucoidan group. Moreover, fucoidan treatment decreased the levels of diamine oxidase and lipopolysaccharides and up-regulated the levels of tight junction proteins. 16S rDNA high-throughput sequencing revealed that fucoidan treatment decreased the abundance of Prevotella and increased the abundance of Alloprevotella. Fucoidan increased the levels of butyric acid and valeric acid compared to the model group. This study provides experimental evidence that dietary fucoidan may prevent colorectal tumorigenesis by regulating gut microecology and body immunity. Meanwhile, fucoidan activated the Hippo pathway and down-regulated the β-catenin pathway to induce tumor cell apoptosis and suppress tumor growth.

Dairy Products and Cancer Risk in a Northern Sweden Population

The role of dairy products in cancer is unclear. We assessed consumption of fermented milk, non-fermented milk, cheese, and butter, estimated from semi-quantitative food frequency questionnaires, in relation to prospective risk of breast, prostate, colorectal, smoking-, and obesity-related cancers in 101,235 subjects, including 12,552 cancer cases, in the population-based Northern Sweden Health and Disease Study. Most analyses (n = 20) rendered null results. In men, we observed an increased prostate cancer risk among high-consumers of cheese (hazard ratio (HR) for highest vs. lowest quintile (Q5-Q1), 1.11; 95% CI, 0.97-1.27; P^trend = 0.013). In women, high-consumers of cheese had a decreased risk of overall cancer (HR Q5-Q1, 0.95; 95% CI, 0.88-1.04; P^trend = 0.039), smoking-related (HR Q5-Q1, 0.84; 95% CI, 0.72-0.97; P^trend ≤ 0.001), and colorectal cancers (HR Q5-Q1, 0.82; 95% CI, 0.63-1.07; P^trend = 0.048). Butter yielded a weak decreased obesity-related cancer risk in women (HR Q5-Q1, 0.91; 95% CI, 0.81-1.02; P^trend = 0.049). Fermented milk yielded HRs below zero in women, but with no clear linear associations. In conclusion, this study does not support any major adverse or beneficial effects of fermented milk, non-fermented milk, cheese, and butter in the diet from a cancer risk perspective.

Association Between Dairy Product Consumption and Colorectal Cancer Risk in Adults: A Systematic Review and Meta-Analysis of Epidemiologic Studies

Dairy product consumption may decrease colorectal cancer (CRC) risk, but very few studies have evaluated the association between different types of dairy products and CRC location. The aim of this systematic review and meta-analysis was to examine the associations between dairy product consumption and CRC incidence. Summary RRs and ORs with 95% CIs were estimated. A total of 15 cohort studies and 14 case-control studies comprising a total of >22,000 cases were included in the quantitative synthesis. The cohort studies showed a consistent significant decrease in CRC risk associated with higher consumption of total dairy products (RR: 0.80; 95% CI: 0.70, 0.91) and total milk (RR: 0.82; 95% CI: 0.76, 0.88) compared with the CRC risk associated with lower consumption. These studies also showed a significant protective association between low-fat milk consumption and CRC (RR: 0.76; 95% CI: 0.66, 0.88), but only for colon cancer (RR: 0.73; 95% CI: 0.61, 0.87). Cheese consumption was inversely associated with the risk of CRC (RR: 0.85; 95% CI: 0.76, 0.96) and proximal colon cancer (RR: 0.74; 95% CI: 0.60, 0.91). No significant associations with CRC were found for the consumption of low-fat dairy products, whole milk, fermented dairy products, or cultured milk. Most of these associations were not supported by the case-control studies. In conclusion, high consumption of total dairy products and total milk was associated with a lower risk of developing CRC at any anatomic location, including the proximal and distal colon and the rectum. Low-fat milk consumption was associated with a lower risk of CRC, but this association was restricted to colon cancer. Cheese consumption was associated with the prevention of CRC, specifically proximal colon cancer. Further studies on larger samples and with longer follow-up periods, along with appropriately designed and executed clinical trials, are warranted to determine whether dairy product consumption affects CRC development.