Colorectal keratins: Integrating nutrition, metabolism and colorectal health.

The colon mucosa is lined with crypts of circa 300 cells, forming a continuous barrier whose roles include absorption of water, recovery of metabolic energy sources (notably short chain fatty acids), secretion of a protective mucus barrier, and physiological signalling. There is high turnover and replenishment of cells in the mucosa, disruption of this may lead to bowel pathologies including cancer and inflammatory bowel disease. Keratins have been implicated in the processes of cell death, epithelial integrity, response to inflammation and as a result are often described as guardians of the colonic epithelium. Keratin proteins carry extensive post-translational modifications, the cofactors for kinases, acetyl transferases and other modification-regulating enzymes are themselves products of metabolism. A cluster of studies has begun to reveal a bidirectional relationship between keratin form and function and metabolism. In this paper we hypothesise a mechanistic interaction between keratins and metabolism is governed through regulation of post-translational modifications and may contribute significantly to the normal functioning of the colon, placing keratins at the centre of a nutrition-metabolism-health triangle.

Still too little evidence: the role of diet in colorectal cancer survivorship - a systematic review.

Colorectal cancer incidence (CRC) is influenced by dietary factors, yet the impact of diet on CRC-specific mortality and recurrence-free survival (RFS) remains unclear. This review provides a narrative summary of existing research on dietary factors affecting CRC-specific mortality, RFS, and disease-free survival (DFS). This study searched electronic databases to identify cross-sectional/prospective research investigating dietary intake on CRC-specific mortality, RFS, or DFS. Twenty-eight studies were included in the corpus. Because of high study heterogeneity, we performed a narrative synthesis of studies. Limited, but suggestive evidence indicates beneficial effects of adhering to the American Cancer Society (ACS) guidelines and a plant rich low-carbohydrate diet on risk of CRC-specific mortality, potentially driven by fiber from cereals, vegetables, and wholegrains, but not fruit. For RFS and DFS, a Western dietary pattern, high intake of refined grains, and sugar sweetened beverages correlated with increased risk of CRC recurrence and development of disease/death. Conversely, greater adherence to the ACS dietary and alcohol guidelines, higher ω-3 polyunsaturated fatty acids, and dark fish consumption reduced risk. Our findings underscore the need for (i) standardized investigations into diet's role in CRC survivorship, including endpoints, and (ii) comprehensive analyses to isolate specific effects within correlated lifestyle components.

Meeting the global protein supply requirements of a growing and ageing population.

Human dietary patterns are a major cause of environmental transformation, with agriculture occupying ~ 50% of global land space, while food production itself is responsible for ~ 30% of all greenhouse gas emissions and 70% of freshwater use. Furthermore, the global population is also growing, such that by 2050, it is estimated to exceed ~ 9 billion. While most of this expansion in population is expected to occur in developing countries, in high-income countries there are also predicted changes in demographics, with major increases in the number of older people. There is a growing consensus that older people have a greater requirement for protein. With a larger and older population, global needs for protein are set to increase. This paper summarises the conclusions from a Rank Prize funded colloquium evaluating novel strategies to meet this increasing global protein need.

Anorexia of ageing is associated with elevated fasted and lower post-prandial ghrelin, independent of ghrelin O-acyltransferase.

The role of ghrelin metabolism in anorexia of ageing is unclear. The aim of this study was to determine acyl-ghrelin, total ghrelin, and ghrelin O-acyltransferase concentrations when fasted and in responses to feeding in older adults exhibiting anorexia of ageing. Twenty-five older adults (OA; 15f, 74 ± 7 years, 24.5 kg·m-2) and twelve younger adults (YA; 6f, 21 ± 2 years, 24.4 kg·m-2) provided a fasted measure of subjective appetite and fasted blood sample (0 min) before consuming a standardised porridge breakfast meal (450 kcal). Appetite was measured every 30 min for 240 min and blood was sampled at 30, 60, 90, 120, 180 and 240 min while participants rested. At 240 min, an ad libitum pasta-based lunch meal was consumed. Older adults were identified as those with healthy appetite (HA-OA) or low appetite (LA-OA), based on habitual energy intake, self-report appetite, BMI, and ad libitum lunch intake. YA ate more at lunch (1108 ± 235 kcal) than HA-OA (653 ± 133 kcal, p = 0.007) and LA-OA (369 ± 168 kcal; p < 0.001). LA-OA, but not HA-OA, had higher fasted concentrations of acyl- and total ghrelin than YA (acyl-ghrelin: 621 ± 307 pg·mL-1 vs. 353 ± 166 pg·mL-1, p = 0.047; total ghrelin: 1333 ± 702 pg·mL-1 vs. 636 ± 251 pg·mL-1, p = 0.006). Acyl-ghrelin (60 min and 90 min) and total ghrelin (90 min) were suppressed to a greater extent for LA-OA than for YA (p < 0.05). No differences were observed in subjective appetite, acyl-to-total ghrelin ratio, or plasma GOAT content (p > 0.1). Higher fasting ghrelin and an augmented ghrelin response to feeding in LA-OA, but not HA-OA, suggests that alterations to ghrelin metabolism are not functions of ageing per se and may be independent causal mechanisms of anorexia of ageing.

Metachronous Colorectal Adenomas Occur Close to the Index Lesion.

GOALS: The aim of this study is to assess the spatial relationship between index and metachronous colorectal adenoma location. BACKGROUND: After the complete excision of a human sporadic colorectal adenoma, patients are at elevated risk of developing a further metachronous adenoma. Data regarding the occurrence site of a metachronous colorectal adenoma relative to the index adenoma are scarce. STUDY: Prospectively maintained databases were interrogated to identify all colonoscopies and adenoma excisions performed over a 10-year period at a single university teaching hospital. Data for the colonic segments at which adenoma removal were reported at index and all subsequent colonoscopies were extracted and 2 allied data sets merged. RESULTS: A total of 15,121 colonoscopies and 4759 polyp events were recorded. Four hundred fifty-two patients [296 male, 156 female, median (range) age 75 (32 to 100) y] developed at least 1 metachronous adenoma at follow-up colonoscopy. When single index events only are considered (ie, synchronous adenoma cases excluded), over 61% of metachronous adenomas were recorded in the same or an adjacent colonic segment. When the full span of the colon is considered, metachronous adenomas were more likely to occur in a section of the colon proximal to that of the index adenoma (41%±5%) than the same (39%±5%) or distal segment (20%±5%; P =0.006; 1-way χ 2 test). CONCLUSIONS: A metachronous human sporadic colorectal adenoma is more likely to be found in the same colonic segment to that of the index adenoma or 1 immediately adjacent. These data suggest a shared origin of metachronous adenoma with preceding lesions, supporting the existence of precancerous fields.

Role of the Microbiome in Regulating Bone Metabolism and Susceptibility to Osteoporosis.

The human microbiota functions at the interface between diet, medication-use, lifestyle, host immune development and health. It is therefore closely aligned with many of the recognised modifiable factors that influence bone mass accrual in the young, and bone maintenance and skeletal decline in older populations. While understanding of the relationship between micro-organisms and bone health is still in its infancy, two decades of broader microbiome research and discovery supports a role of the human gut microbiome in the regulation of bone metabolism and pathogenesis of osteoporosis as well as its prevention and treatment. Pre-clinical research has demonstrated biological interactions between the microbiome and bone metabolism. Furthermore, observational studies and randomized clinical trials have indicated that therapeutic manipulation of the microbiota by oral administration of probiotics may influence bone turnover and prevent bone loss in humans. In this paper, we summarize the content, discussion and conclusions of a workshop held by the Osteoporosis and Bone Research Academy of the Royal Osteoporosis Society in October, 2020. We provide a detailed review of the literature examining the relationship between the microbiota and bone health in animal models and in humans, as well as formulating the agenda for key research priorities required to advance this field. We also underscore the potential pitfalls in this research field that should be avoided and provide methodological recommendations to facilitate bridging the gap from promising concept to a potential cause and intervention target for osteoporosis.

Vitamin D supplementation in people with IBS has no effect on symptom severity and quality of life: results of a randomised controlled trial.

PURPOSE: Several small trials suggest a benefit of vitamin D supplementation in irritable bowel syndrome (IBS). The generalisability of these reports is limited by their design and scale. This study aimed to assess whether vitamin D supplementation improved IBS symptoms in a UK community setting. METHODS: This was a randomised, double-blind, placebo-controlled study. Participants were recruited from the community in winter months between December 2017 and March 2019. 135 participants received either vitamin D (3,000 IU p.d.) or placebo for 12 weeks. The primary outcome measure was change in IBS symptom severity; secondary outcomes included change in IBS-related quality of life. RESULTS: The participants were analysed on an intent-to-treat basis. 60% of participants were vitamin D deficient or insufficient at baseline. Although vitamin D levels increased in the intervention arm relative to placebo (45.1 ± 32.88 nmol/L vs 3.1 ± 26.15 nmol/L; p < 0.001). There was no difference in the change of IBS symptom severity between the active and placebo trial arms (- 62.5 ± 91.57 vs - 75.2 ± 84.35, p = 0.426) over time. Similarly there was no difference between trial arms in τhe change in quality of life (- 7.7 ± 25.36 vs - 11.31 ± 25.02, p = 0.427). CONCLUSIONS: There is no case for advocating use of vitamin D in the management of IBS symptoms. The prevalence of vitamin D insufficiency suggests routine screening and supplementation should be implemented in this population for general health reasons. This trial was retrospectively registered with ISRCTN (ISRCTN13277340) on 24th April 2018 after recruiting had been initiated.

Metastasising Fibroblasts Show an HDAC6-Dependent Increase in Migration Speed and Loss of Directionality Linked to Major Changes in the Vimentin Interactome.

Metastasising cells express the intermediate filament protein vimentin, which is used to diagnose invasive tumours in the clinic. We aimed to clarify how vimentin regulates the motility of metastasising fibroblasts. STED super-resolution microscopy, live-cell imaging and quantitative proteomics revealed that oncogene-expressing and metastasising fibroblasts show a less-elongated cell shape, reduced cell spreading, increased cell migration speed, reduced directionality, and stronger coupling between these migration parameters compared to normal control cells. In total, we identified and compared 555 proteins in the vimentin interactome. In metastasising cells, the levels of keratin 18 and Rab5C were increased, while those of actin and collagen were decreased. Inhibition of HDAC6 reversed the shape, spreading and migration phenotypes of metastasising cells back to normal. Inhibition of HDAC6 also decreased the levels of talin 1, tropomyosin, Rab GDI ß, collagen and emilin 1 in the vimentin interactome, and partially reversed the nanoscale vimentin organisation in oncogene-expressing cells. These findings describe the changes in the vimentin interactome and nanoscale distribution that accompany the defective cell shape, spreading and migration of metastasising cells. These results support the hypothesis that oncogenes can act through HDAC6 to regulate the vimentin binding of the cytoskeletal and cell-extracellular matrix adhesion components that contribute to the defective motility of metastasising cells.

Comparing supermarket loyalty card data with traditional diet survey data for understanding how protein is purchased and consumed in older adults for the UK, 2014-16.

BACKGROUND: Our ability to understand population-level dietary intake patterns is dependent on having access to high quality data. Diet surveys are common diet assessment methods, but can be limited by bias associated with under-reporting. Food purchases tracked using supermarket loyalty card records may supplement traditional surveys, however they are rarely available to academics and policy makers. The aim of our study is to explore population level patterns of protein purchasing and consumption in ageing adults (40 years onwards). METHODS: We used diet survey data from the National Diet and Nutrition Survey (2014-16) on food consumption, and loyalty card records on food purchases from a major high street supermarket retailer (2016-17) covering the UK. We computed the percentage of total energy derived from protein, protein intake per kg of body mass, and percentage of protein acquired by food type. RESULTS: We found that protein consumption (as the percentage of total energy purchased) increased between ages 40-65 years, and declined thereafter. In comparison, protein purchased in supermarkets was roughly 2-2.5 percentage points lower at each year of age. The proportion of adults meeting recommended levels of protein was lowest in age groups 55-69 and 70+. The time of protein consumption was skewed towards evening meals, with low intakes during breakfast or between main meals. Meat, fish and poultry dominated as sources of protein purchased and consumed, although adults also acquired a large share of their protein from dairy and bread, with little from plant protein. CONCLUSIONS: Our study provides novel insights into how protein is purchased and consumed by ageing adults in the UK. Supermarket loyalty card data can reveal patterns of protein purchasing that when combined with traditional sources of dietary intake may enhance our understanding of dietary behaviours.

Protein Valuation in Food Choice Is Positively Associated with Lean Mass in Older Adults.

BACKGROUND: Calorie for calorie, protein is more satiating than carbohydrate or fat. However, it remains unclear whether humans perceive calories derived from these macronutrients equally and whether lean mass is associated with a tendency to "value" protein when dietary decisions are made. OBJECTIVES: This study aimed to determine the test-retest reliability of a novel method for quantifying macronutrient valuations in human volunteers and to determine whether "protein valuation" is associated with a higher fat-free mass index (FFMI) in older adults. METHODS: A 2-alternative, forced-choice task in which 25 foods were compared in 300 trials was undertaken in 2 studies. In study 1, participants (age range 19-71 y, n = 92) attended 2 test sessions, spaced 1 wk apart. In study 2, older adults (age range 40-85 y; n = 91) completed the food-choice task and assessed the test foods for liking, expected satiety, and perceived healthiness. Body composition and habitual protein intake were assessed in both studies. Data were analyzed through the use of individual binomial logistic regressions and multilevel binomial logistic regressions. RESULTS: In study 1, measures of macronutrient valuation showed excellent test-retest reliability; responses in the forced-choice task were highly correlated (week 1 compared with week 2; protein, r = 0.83, P < 0.001; carbohydrate, r = 0.90, P < 0.001; fat, r = 0.90, P < 0.001). Calorie for calorie, protein and carbohydrate were stronger predictors of choice than fat (P < 0.001). In study 2, protein was a stronger predictor than both carbohydrate (P = 0.039) and fat (P = 0.003), and a positive interaction was observed between protein valuation and FFMI (OR = 1.64; 95% CI: 1.38, 1.95; P < 0.001). This was the case after controlling for age, gender, liking for foods, and habitual protein consumption. CONCLUSIONS: Together, these findings demonstrate that adult humans value calories derived from protein, carbohydrate, and fat differently, and that the tendency to value protein is associated with greater lean mass in older adults.

Correction to: Proteomic identification and characterization of hepatic glyoxalase 1 dysregulation in non-alcoholic fatty liver disease.

[This corrects the article DOI: 10.1186/s12953-018-0131-y.].

Proteomic identification and characterization of hepatic glyoxalase 1 dysregulation in non-alcoholic fatty liver disease.

Background: Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide. However, its molecular pathogenesis is incompletely characterized and clinical biomarkers remain scarce. The aims of these experiments were to identify and characterize liver protein alterations in an animal model of early, diet-related, liver injury and to assess novel candidate biomarkers in NAFLD patients. Methods: Liver membrane and cytosolic protein fractions from high fat fed apolipoprotein E knockout (ApoE-/-) animals were analyzed by quantitative proteomics, utilizing isobaric tags for relative and absolute quantitation (iTRAQ) combined with nano-liquid chromatography and tandem mass spectrometry (nLC-MS/MS). Differential protein expression was confirmed independently by immunoblotting and immunohistochemistry in both murine tissue and biopsies from paediatric NAFLD patients. Candidate biomarkers were analyzed by enzyme-linked immunosorbent assay in serum from adult NAFLD patients. Results: Through proteomic profiling, we identified decreased expression of hepatic glyoxalase 1 (GLO1) in a murine model. GLO1 protein expression was also found altered in tissue biopsies from paediatric NAFLD patients. In vitro experiments demonstrated that, in response to lipid loading in hepatocytes, GLO1 is first hyperacetylated then ubiquitinated and degraded, leading to an increase in reactive methylglyoxal. In a cohort of 59 biopsy-confirmed adult NAFLD patients, increased serum levels of the primary methylglyoxal-derived advanced glycation endproduct, hydroimidazolone (MG-H1) were significantly correlated with body mass index (r = 0.520, p < 0.0001). Conclusion: Collectively these results demonstrate the dysregulation of GLO1 in NAFLD and implicate the acetylation-ubquitination degradation pathway as the functional mechanism. Further investigation of the role of GLO1 in the molecular pathogenesis of NAFLD is warranted.

Systematic literature review shows that appetite rating does not predict energy intake.

Ratings of appetite are commonly used to assess appetite modification following an intervention. Subjectively rated appetite is a widely employed proxy measure for energy intake (EI), measurement of which requires greater time and resources. However, the validity of appetite as a reliable predictor of EI has not yet been reviewed systematically. This literature search identified studies that quantified both appetite ratings and EI. Outcomes were predefined as: (1) agreement between self-reported appetite scores and EI; (2) no agreement between self-reported appetitescores and EI. The presence of direct statistical comparison between the endpoints, intervention type and study population were also recorded. 462 papers were included in this review. Appetite scores failed to correspond with EI in 51.3% of the total studies. Only 6% of all studies evaluated here reported a direct statistical comparison between appetite scores and EI. χ2 analysis demonstrated that any relationship between EI and appetite was independent of study type stratification by age, gender or sample size. The very substantive corpus reviewed allows us to conclude that self-reported appetite ratings of appetite do not reliably predict EI. Caution should be exercised when drawing conclusions based from self-reported appetite scores in relation to prospective EI.

Dysbiosis of the gut microbiota in disease.

There is growing evidence that dysbiosis of the gut microbiota is associated with the pathogenesis of both intestinal and extra-intestinal disorders. Intestinal disorders include inflammatory bowel disease, irritable bowel syndrome (IBS), and coeliac disease, while extra-intestinal disorders include allergy, asthma, metabolic syndrome, cardiovascular disease, and obesity.

A mathematical model of the colon crypt capturing compositional dynamic interactions between cell types.

Models of the development and early progression of colorectal cancer are based upon understanding the cycle of stem cell turnover, proliferation, differentiation and death. Existing crypt compartmental models feature a linear pathway of cell types, with little regulatory mechanism. Previous work has shown that there are perturbations in the enteroendocrine cell population of macroscopically normal crypts, a compartment not included in existing models. We show that existing models do not adequately recapitulate the dynamics of cell fate pathways in the crypt. We report the progressive development, iterative testing and fitting of a developed compartmental model with additional cell types, and which includes feedback mechanisms and cross-regulatory mechanisms between cell types. The fitting of the model to existing data sets suggests a need to invoke cross-talk between cell types as a feature of colon crypt cycle models.

Pulsatile exposure to simulated reflux leads to changes in gene expression in a 3D model of oesophageal mucosa.

Oesophageal exposure to duodenogastroesophageal refluxate is implicated in the development of Barrett's metaplasia (BM), with increased risk of progression to oesophageal adenocarcinoma. The literature proposes that reflux exposure activates NF-κB, driving the aberrant expression of intestine-specific caudal-related homeobox (CDX) genes. However, early events in the pathogenesis of BM from normal epithelium are poorly understood. To investigate this, our study subjected a 3D model of the normal human oesophageal mucosa to repeated, pulsatile exposure to specific bile components and examined changes in gene expression. Initial 2D experiments with a range of bile salts observed that taurochenodeoxycholate (TCDC) impacted upon NF-κB activation without causing cell death. Informed by this, the 3D oesophageal model was repeatedly exposed to TCDC in the presence and absence of acid, and the epithelial cells underwent gene expression profiling. We identified ~300 differentially expressed genes following each treatment, with a large and significant overlap between treatments. Enrichment analysis (Broad GSEA, DAVID and Metacore™; GeneGo Inc) identified multiple gene sets related to cell signalling, inflammation, proliferation, differentiation and cell adhesion. Specifically NF-κB activation, Wnt signalling, cell adhesion and targets for the transcription factors PTF1A and HNF4α were highlighted. Our data suggest that HNF4α isoform switching may be an early event in Barrett's pathogenesis. CDX1/2 targets were, however, not enriched, suggesting that although CDX1/2 activation reportedly plays a role in BM development, it may not be an initial event. Our findings highlight new areas for investigation in the earliest stages of BM pathogenesis of oesophageal diseases and new potential therapeutic targets.

Can an educational video improve the adequacy of bowel preparation for patients undergoing their first colonoscopy? Results of the EBOPS RCT.

Background and study aims The aim of this study was to assess the effect of an educational video on the quality of bowel preparation of patients from a UK population attending for their first colonoscopy. Patients and methods A prospective, endoscopist-blinded trial with 1:1 allocation was performed. Patients referred for their first colonoscopy were recruited between February 2019 and December 2019. All participants were prescribed Moviprep and received the trial site's standard written bowel preparation instructions, with the intervention group also receiving a bespoke educational video. Adequacy of bowel preparation (defined as a Boston Bowel Preparation Scale of ≥2 in each segment of the bowel) and polyp detection rates (PDRs) were compared. Fisher's chi squared test was utilized with P <0.05 as the threshold for significance. Results A total of 509 participants completed the trial from six centers; 251 were randomized to the intervention group. The mean age was 57 years and 52.3% were female. The primary endpoint was met with an adequacy rate of 216 of 251 (86.1%) in the intervention group, compared with 205 of 259 (79.1%) in the control group ( P <0.05, odds ratio [OR] 1.626, 95% CI 1.017-2.614). The PDR was significantly higher in the intervention group (39% vs 30%, OR 1.51, 95% CI 1.04-2.19, P <0.05). Conclusions An educational video leads to improved bowel preparation for patients attending for their first colonoscopy, and is also associated with greater detection of polyps. Widespread adoption of an educational video incurs minimal investment, but would reduce the number of inadequate procedures, missed pathology, and the cost that both these incur.

Adherence to the Eatwell Guide and population and planetary health: A Rank Prize Forum report.

This report summarises a Forum conducted in June 2023 to explore the current state of the knowledge around the Eatwell Guide, which is the UK government's healthy eating tool, in relation to population and planetary health. The 1.5-day Forum highlighted the limited, albeit promising evidence linking higher adherence to the Eatwell Guide with favourable health outcomes, including reduced overall mortality risk, lower abdominal obesity in post-menopausal women and improved cardiometabolic health markers. Similarly, evidence was presented to suggest that higher adherence to the Eatwell Guide is associated with reduced greenhouse gas emissions. Presentations were given around cultural adaptations of the Eatwell Guide, including African Heritage and South Asian versions, which are designed to increase the acceptability and uptake of the Eatwell Guide in these communities in the United Kingdom. Presentations highlighted ongoing work relevant to the applications of the Eatwell Guide in randomised controlled trials and public health settings, including the development of a screening tool to quantify Eatwell Guide adherence. The Forum ended with a World Café-style event, in which the strengths and limitations of the Eatwell Guide were discussed, and directions for future research were identified. This Forum report serves as a primer on the current state of the knowledge on the Eatwell Guide and population and planetary health and will be of interest to researchers, healthcare professionals and public health officials.

Promotion of cancer metastasis: candidate validation using an iTRAQ-based approach.

Evaluation of: Ghosh D, Li Z, Tan XF, Lim TK, Mao Y, Lin Q. RAQ based quantitative proteomics approach validated the role of calcyclin binding protein (CacyBP) in promoting colorectal cancer metastasis. Mol. Cell Proteomics 12(7), 1865-1880 (2013). The use of iTRAQ-based relative quantification is demonstrated by Ghosh et al. to analyze the downstream effectors of a calcyclin-binding protein, which is proposed to promote colorectal cancer progression. These findings are reviewed and discussed in relation to the need to establish robust in vitro model cell lines for identification of cancer-specific pathways and to confirm the leads generated by proteomic analysis.