Introduction
This symposium (20 September 2023, Leiden, Netherlands) was organized as a farewell symposium for Jan-Willem van der Kamp, who has been active in the areas of dietary fibre and whole grain for decades. It revealed new insights, tools and perspectives for major innovations in topics ranging from personalized nutrition, combating diseases, reformulation of products (more fibre, less sugars and fats) whilst maintaining product attractiveness and improving public health, especially of low-income consumers. Highlights and perspectives are outlined below. Detailed results, references, contact details of speakers can be found in the presentations and the Symposium programme. For further information you may also contact
Precision prebiotics - dietary fibres with consistent predicted microbiome response
Many prebiotic fibres are fermented by a large number of gut bacteria, resulting in major differences in bacterial responses depending on the microbiome composition of individuals. Keynote speaker Professor Bruce Hamaker highlighted that fibres with complex chemical or physical structures (often with limited or moderate solubility and fermentability) can only be degraded by specific bacteria.
Precision prebiotics – general health and Parkinson’s disease
Precision prebiotic mixtures may be tailored for robust (i.e. not depending on an individual’s microbiome) promotion of target bacteria and related health responses. Studies with a small cohort of Parkinson’s disease participants showed that the applied precision prebiotic mixture was highly tolerable and effective in only 10 days in increasing gut epithelial health and reducing brain injury.
Synergistic effects of mixtures of fibres and fibres with other bioactive compounds
Synergistic effects presented by Jan Willem van der Kamp and Frank Schuren indicated:
- Mixtures of fibres and in combination with other bioactive compounds contributed more effectively than single fibres to the production of short chain fatty acids and a diverse gut microbiome.
- Single fibres eliciting individual responses of gut microbiota (responders vs. non-responders), did not elicit such differences when added as a fibre mixture.
- Cereal bran contributed to increased microbiota diversity and/or abundance.
- Recent meta-analyses on studies with dietary fibre and whole grain show that 25 g/day of dietary fibre is associated with a similar risk reduction for non-communicable diseases as ~ 50g whole grains/day –which contains only 4-6g fibre. This shows the synergistic effect of fibre in combination with a wide range of bioactive compounds in case of whole grain.
Sugar replacement based on polymer science; the power of fibres and fibre-rich by-products
The key challenge of sugar and fat replacement in bakery- and other products is how to get, or keep, a good texture. Stefano Renzetti’ s approach, based on integrating food technology with fundamental theories from polymer science resulted in the reformulation of food products with major reductions in sugar levels and increased levels of fibres. Sugar acts as a humectant, characterized by its water-absorbing capacity (interaction parameter Χeff ), and as a plasticizer, characterized by its capacity to softening texture (hydrogen bond density parameter Φw, eff). One example of using these new reformulation principles is the improved sensory perception of a pound cake with 30% less fat, 30% less sugar, 10% less flour, more water and more fibres, both soluble (plasticizer, humectant) and insoluble (soft filler).
Consumers – how to bridge the fibre gap
Louise Dye reported that in the UK the intake of fibre and micronutrients decreases with decreasing income; persons with low socio-economic status (SES) are more strongly affected by non-communicable diseases. Studies and efforts for increasing fibre access and intake are part of the h3 project - Healthy soil, Healthy food, Healthy people. Among the barriers for sufficient fibre consumption in low SES populations are low health literacy, focus on convenience (more important than health) and lack of economic resources and of social support. Effective communication specifically for this low SES group and a framework for product reformulation enriched in fibres are important factors for realizing health improvements – with a key role for food technology.
Can health benefits be maximized? Beyond ‘just more fibre’?
As in many countries, life expectancy in the Netherlands increased in the past decades but the number of healthy years without chronic diseases decreased (Suzan Wopereis). Many consumers will or cannot change their dietary habits to comply with the recommended patterns. However, by finding and exploiting synergistic effects of mixtures of fibres and other bioactive compounds, significant benefits to health may be realized also with less than ‘perfect‘ diets. Searching, finding and optimizing synergistic effects of mixtures is a challenge with multiple facets.
Optimizing of benefits of mixtures with reliable rapid methods
This wide range of options may be assessed effectively with reliable rapid methods, such as TNO’s i-screen system. Frank Schuren and Femke Hoevenaars presented results based on th highthroughput TNO I-screen system for evaluating the effects of fibres on the gut microbiota composition and its metabolic activity. These in-vitro results corresponded well with those of subsequent in-vivo studies. Suzan Wopereis outlined multiple examples of how the innovative PhenFlex methodology for assessing health effects was applied to reveal the subtle impact of whole wheat and fibres on health from a one-size-fits-all as well as from a personalized approach.
Perspectives: combination of expertises for additional benefits to health
The symposium presented recently developed insights, plans, technologies and marked progress. Combination and integration of the presented approaches may result in additional benefits for health as is outlined in the hypothetical cases below.
1. Precision Prebiotic fibres for health also contributing to sugar and fat reduction
- Precision prebiotics can contribute to both specific and overall health benefits (Hamaker).
- Fibres with specific physico-chemical characteristics are key contributors to healthier foods (less sugar and fat, more fibre) (Renzetti).
Fibres fulfilling both physico-chemical and precision prebiotic requirements may be found:
- Based on insight.
- Supported by high throughput i-screen assessment for initial searches (Schuren) and by assessment of health benefits with Phenflex methodology (Wopereis).
2. Fibre-rich by-products – impact on the gut microbiome and for sugar replacement
- Fibre-rich by-products are being assessed for their technological performance (Renzetti).
- Combinations of fibres and of fibres with a wide range of bioactive compounds show major synergistic effects/ benefits to health (Van der Kamp, Schuren).
- With an approach similar to 1. stronger benefits to health may be realized.
3. How to improve intake of whole grains in populations?
- The fortification of food products with fibers/whole grains, while reducing simple carbohydrates (Louise Dye) to also reach persons with low socio-economic status.
- The communication around whole grains / fibres (Dye).
- Building a dossier to apply for a health claim on whole grain wheat (e.g. PhenFlex, (Wopereis).
- A personalized (communication) approach to increase awareness and adherence to whole grains/fibres (Wopereis).
4.Note: TNO is discussing a new Public Private Partnership Project
Fibres for health. Targeted microbiome modulation through in vitro pre-screening of optimal fibres
Improving health and preventing disease is now an important aspect of healthcare. Dietary fibres are generally considered as healthy and to function, amongst others, via the gut microbiome. Although positive effects of increased fibre intake on human health are described, it has also become clear that not every fibre is effective for every individual (and its gut microbiome). To further improve health effects a better alignment of choosing the right fiber(mix) for a specific individual is highly needed.
We have shown in a previous study that short-term in vitro exposure of individual microbiome samples to selected fibers is predictive for longer-term in vivo effects. In this study we aim at selecting the best fiber combination for each individual based on in vitro analysis , followed by a human nutritional intervention study in which each individual receives the best fibre product for his/her microbiome. This requires a novel, flexible set-up of a human intervention study which will include multiple intervention products. Since the expected power of this study will be much higher, only a small number of participants will be needed to allow for determining statistical significance. This will simplify precision nutrition advices and thereby speed-up nutritional lifestyle interventions aimed at preventing human disease.
