Impact of non-digestible carbohydrates on biomarkers of GI health: a human intervention study

Lead Research Organisation: Newcastle University
Department Name: Institute for Ageing and Health

Abstract

What we eat affects the health of all parts of the body including the gut. Symptoms, disorders and diseases of the large bowel are major causes of anxiety, visits to general practitioners and medical treatment. In particular, the large bowel is one of the commonest sites for cancer development. Large scale observational studies of dietary practices and associated incidence of cancer provide very strong evidence that dietary choices and nutritional status (e.g. obesity) influence risk of cancer in the large bowel (colorectal cancer; CRC). Such evidence is very encouraging because it suggests that many cases of bowel cancer could be avoided by appropriate dietary choices and/or by the development of novel foods or dietary agents with anti-cancer properties. Identification of beneficial dietary agents requires intervention studies i.e. carefully controlled experiments in which volunteers are given known amounts of the test agent. For both practical and ethical reasons, it is seldom appropriate to use the development of cancer as the endpoint in such experiments and there is a need to use surrogate outcome measures. This is analogous to using blood pressure or blood cholesterol concentration as surrogate outcome measures (or biomarkers) in studies of diet and heart disease risk. Unfortunately, in the area of diet and gut health, progress is hampered by the lack of robust biomarkers of CRC risk for use as surrogate endpoints. To address this gap, we have developed a number of novel biomarkers of diet-related CRC risk which can be measured in small samples (biopsies) taken during clinical examination of the large bowel. We have shown that these biomarkers can be detected BEFORE the development of CRC and so may be a useful tool to identify those at higher risk of the disease. In our on-going work, we are investigating relationships between what people eat (and other aspects of lifestyle) and these biomarkers in a cross-sectional study. The next logical step is to test how the most promising biomarkers respond to dietary intervention to determine how useful they will be as biomarkers of gut health. We will do this by carrying out a carefully controlled experiment in which volunteers will be given food supplements of resistant starch (RS) and polydextrose (PD) - both are carbohydrates with special properties. They are widely used food ingredients for which there is already evidence that they may help reduce CRC risk. Both food agents show bioactivity in the large bowel where they appear to have beneficial effects on gut physiology and immune function including anti-inflammatory effects. In our human intervention study, 70 healthy volunteers will be given RS and/or PD or another carbohydrate with no effects on the large bowel (a placebo) for 7 weeks. We will collect tiny pinch samples of the lining of the gut (mucosal biopsies) before and after the intervention for biomarker measurement. These biomarker studies will include measurement of genes which are known to be involved in the early stages of the development of cancer and which may be modifiable by changing diet. Dietary components such as RS and PD may influence how genes are switched on and off by affecting regulatory marks on DNA known as DNA methylation so we will quantify DNA methylation for a panel of key cancer-related genes. We will also measure the rates at which cells are been produced (cell proliferation) in the gut lining because faster cell proliferation appears to indicate higher CRC risk. In addition we will collect blood and stool for measurements of markers of inflammation. There is growing evidence that poor diet and obesity can lead to the development of a chronic inflammatory state and that this may predispose to CRC. Through their fermentation by bacteria in the large bowel, RS and PD may help reduce inflammation and so protect gut health.

Technical Summary

Epidemiological evidence shows that dietary choices influence risk of colorectal cancer (CRC). Identification of beneficial dietary agents requires intervention studies but progress in this area is hampered by the lack of robust risk biomarkers for use as surrogate endpoints. To address this gap, we have developed a number of novel biomarkers of diet-related CRC risk measured in colo-rectal mucosal biopsies. These biomarkers include protein biomarkers, DNA methylation markers and inflammation markers. In on-going work, we are investigating relationships between dietary exposure and these biomarkers in a cross-sectional study. The next logical step is to test responses of a panel of the most promising biomarkers to dietary intervention to determine their utility as biomarkers of GI health and potential in future studies. We propose to use resistant starch (RS) and polydextrose (PD) as our model non-digestible carbohydrate (NDC) intervention agents. Both agents show bioactivity in the large bowel where they are fermented (to a greater or lesser extent) producing short-chain fatty acids (SCFA) including butyrate. Butyrate has beneficial effects on gut physiology and immune function including anti-inflammatory effects. It is probable that NDC exert anti-neoplastic effects via butyrate. We will carry out a human intervention study with healthy volunteers using a 2*2 factorial design. 70 volunteers will consume RS and/or PD or placebo for 50d. Bioactivity of the NDC in the large bowel will be monitored by measurement of SCFA in stool and urine. We will collect colorectal mucosal biopsies before and after the intervention for biomarker measurement including methylation of tumour-related genes, crypt cell kinetics, expression of cell cycle regulatory genes CDK4 and GADD45A and protein biomarkers (CK8 a diet-related biomarker of CRC risk). In addition we will collect blood and stool for measurements of inflammatory markers viz. CRP and calprotectin respectively.

Planned Impact

1. Who will benefit from this research? This project is designed to enhance understanding of the links between diet and function and health of the gut in the context of the BBSRC DRINC initiative. We anticipate that this research will have a wide range of beneficiaries (in addition to the academic community) including: Industrial members of the BBSRC DRINC initiative; The wider food industry including those developing novel foods or food ingredients aimed at improved gut health and those advising consumers; Regulators with responsibilities in the area of food and health e.g. the European Food Safety Authority and the UK's Advisory Committee on Novel Foods and Processes; Manufacturers of diagnostic and other tests for gut function and bowel cancer risk; The general public. 2. How will they benefit from this research? Industrial members of the BBSRC DRINC initiative will have access to emerging data and new ideas in respect of both biomarkers of gut function and bowel cancer risk and the impact of diet on these processes in advance of publication. Outcomes from this research will provide the wider food industry with more robust outcome measures and tools for R&D in the area of functional foods for improved gut health. The lack of reliable measures of gut health is a major impediment for regulators assessing requests from industry for authorisation of new foods to be placed in the European market and for claims about new or existing food products. This project will provide objective outcome measures which can be used directly in humans (the most critical type of evidence necessary for regulators). The testing of novel biomarkers within this project will provide manufacturers of diagnostic and other tests with objective evidence of the utility of putative biomarkers in a well-designed human intervention study. Often such manufacturers have excellent laboratory facilities but restricted access to studies in humans. The general public are expected to benefit from this project in at least 3 ways i) through provision of objective information about the effects of two widely used food components on gut function and health; ii) by enhancing the quality and robustness of evidence which will be required to make claims about new (or existing) food products and iii) encouraging the food industry to produce additional food products or ingredients which are aimed to improve gut function and to reduce bowel cancer risk. 3. What will be done to ensure that they have the opportunity to benefit from this research? We will work towards timely dissemination of the outcomes from the research project via the conventional route of academic publications using open access journals where possible. This will ensure widespread access by all stakeholders to the project outcomes following the important quality assurance step of peer review. In addition, we will present findings from the project on an on-going basis via conference presentations and we will target conferences and workshops attended by diverse user groups including industry and regulators. As an integral part of the DRINC initiative, we will participate in the twice yearly dissemination events which will provide opportunities for one-to-one meetings with food industry representatives to discuss emerging findings and to identify opportunities for further developments. We do not anticipate that this project will lead to exploitable intellectual property but we will take appropriate action should commercialisation opportunities be identified. The Institute for Ageing and Health (Newcastle University) has a Technology Transfer Officer to support such actions, and the Regional Development Agency has established a Centre for Excellence in the Life Sciences which is developing a major programme of activity aimed at exploitation and dissemination of research. Dissemination to the public and other stakeholders will be via the University and IFR websites

Publications

10 25 50
 
Description In an attempt to develop novel diet-responsive biomarkers of bowel health, we have undertaken a dietary intervention study in healthy human adults. The participants were recruited from a gastroenterology clinic on the basis that investigations had shown that they were "healthy" i.e. had no evidence of bowel cancer or of gastrointestinal inflammatory disease. We collected biological samples (blood, stool, urine and mucosal biopsies (small "pinch" samples of the bowel lining)) before and 50 days after the participants consumed sachets containing non-digestible carbohydrates daily.

We observed that the intervention produced multiple effects on biomarkers in each of the types of biological sample. In addition, some biomarkers were influenced by participant characteristics e.g. age and body fatness. Work is on-going to interpret our findings.
Exploitation Route If we are successful in identifying one or more (possibly a small panel) of diet-responsive biomarkers of bowel health, these could be used i) as surrogate outcomes in future dietary intervention studies and/or ii) in surveys, or other epidemiolgical studies, of links between diet and gut health.
Sectors Agriculture, Food and Drink,Healthcare

 
Description Advisory Committee on Novel Foods and Processes (ACNFP) Workshop on Novel Foods
Geographic Reach Europe 
Policy Influence Type Participation in a advisory committee
URL https://acnfp.food.gov.uk/
 
Description Co-chair of Workshop - ESRC/BBSRC Epigenetics Showcase. London. May 2019
Geographic Reach Europe 
Policy Influence Type Participation in a advisory committee
URL https://bbsrc.ukri.org/news/events/2019/1905-epigenetics-showcase/
 
Description MRC Nutrition and Health Review Workshop, 7th - 8th July 2016
Geographic Reach National 
Policy Influence Type Participation in a advisory committee
 
Description MRC Review of Nutrition and Human Health Research, 14 Oct 2016
Geographic Reach National 
Policy Influence Type Participation in a advisory committee
 
Description MRC Review of Nutrition and Human Health research - 17th March
Geographic Reach National 
Policy Influence Type Participation in a advisory committee
 
Description World Cancer Research Fund International Grants Panel
Geographic Reach Multiple continents/international 
Policy Influence Type Participation in a advisory committee
Impact John please add
URL https://www.wcrf-uk.org/
 
Description World Cancer Research Fund International Grants Panel (panel member). London. June 2019
Geographic Reach Multiple continents/international 
Policy Influence Type Participation in a advisory committee
URL https://www.wcrf-uk.org/
 
Description Adherence to the WCRF/AICR Cancer Prevention Recommendations and Cancer Risk and Survival in the UK
Amount £283,573 (GBP)
Funding ID IIG_FULL_2020_032 
Organisation World Cancer Research Fund 
Sector Charity/Non Profit
Country Global
Start 11/2020 
End 10/2023
 
Description FSF - Cancer stem cells in colorectal cancer/Northumbria Health Care NHS Foundation Trust
Amount £51,980 (GBP)
Organisation National Institute for Health Research 
Sector Public
Country United Kingdom
Start 09/2010 
End 12/2012
 
Description Collaboration: Erasmus Student Placement 
Organisation IMC University of Applied Sciences Krems
Country Austria 
Sector Academic/University 
PI Contribution In the last year we have been able to take an ERASMUS student, Martina Stiegler, from Austria, to investigate the acceptability of home urine collection and storage amongst the general public. This is important as it will enable us to better understand how the findings of the MAIN study could be best applied in an epidemiological setting.
Collaborator Contribution Student placement
Impact to investigate the acceptability of home urine collection and storage amongst the general public. This is important as it will enable us to better understand how the findings of the MAIN study could be best applied in an epidemiological setting.
Start Year 2015
 
Description Rowett Institute of Nutrition and Health 
Organisation University of Aberdeen
Department The Rowett Institute
Country United Kingdom 
Sector Academic/University 
PI Contribution Analysis of faecal microbiome
Collaborator Contribution We (Newcastle University) have provided stool samples from healthy human participants before and after a dietary intervention study. Professor Flint and colleagues have undertaken quantification of abundance of selected bacteria in these stool samples.
Impact None as yet.
Start Year 2013
 
Description Technical University of Munich 
Organisation Technical University of Munich
Country Germany 
Sector Academic/University 
PI Contribution In this is a collaboration with Professor Dirk Haller, we (University of Newcastle) have provided colorectal mucosal samples from human participants.
Collaborator Contribution Professor Dirk Haller and colleagues have undertaken analyses for novel inflammation-related markers.
Impact None as yet.
Start Year 2013
 
Description Epigenetics Matters: Public Engagement Event 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Professional Practitioners
Results and Impact More than 50 participants attended the lecture. This led to discussion with several research groups afterwards.
Year(s) Of Engagement Activity 2018
 
Description JPI-HDHL: Biomarkers for Nutrition and Health Agenda for Final Symposium 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Approximately 40 researchers from a wide range of disciplines and at all levels from PhD students to senior professors took part in an interactive workshop to discuss the role of amylase/trypsin-inhibitors (ATIs) in adverse reactions to wheat consumption, which may affect up to 10% of the population.

The outcomes from this workshop have been written up and are being considered for publication by an international journal.
Year(s) Of Engagement Activity 2020
 
Description NuGO participants Assembly. Denmark 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Discussion among representatives of European universities and research institutes on how best to promote nutrigenomics research
Year(s) Of Engagement Activity 2016
 
Description Nutrition Society Symposium. 'Obesity and bowel cancer: mechanisms to interventions' 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact More than 50 participants attended the lecture. This led to discussion with several research groups afterwards and requests for collaboration.
Year(s) Of Engagement Activity 2018