The global gut health is variously estimated at around €15-30 million and predicted to grow by around 8% annually at least to the end of the decade, but what are the opportunities and hurdles for companies wanting to win it?

In this series of articles, NutraIngredients, discusses some of the key issues and challenges facing the nutraceutical and food ingredient industry today. In this article we hear from Martin Ham, Business Development Manager at NIZO.

NutraIngredients (NI): Why is the gut health market hot right now?

Martin Ham: There are a number of factors combining to drive growth in the gut and digestive health market. One is that consumers are increasingly aware of the importance of gut health and comfort, and that they can, to some extent, manage that themselves through food choices and supplements. This is linked to the fact that global populations are ageing, and more and more people are living with chronic gastric disorders. At the same time, scientists are gaining better understanding of both the importance of the gut (microbiome) on human health and how we can influence it.

NI: How does the gut (microbiome) affect health?

MH: Most obviously, a healthy gut can promote digestive health such as reducing constipation and bloating. But it also has more systemic effects. For example, gut health plays a vital role in our immune system whether by inhibiting pathogens from binding to cells in our digestive tract or through direct modulation of immune cells. Moreover, the concept of the “gut-brain-axis”, or “microbiota-gut-brain-communication”, has become largely accepted over the last decade. This two-way molecular communication between the gut and the brain is suspected of impacting our mood, ability to deal with stress, sleep patterns and even behaviour.

NI: What kind of functional ingredients are important in the market?

MH: Currently, the largest area is probiotics – microbes that have a positive effect, for example, by metabolising otherwise undigestible food components or producing beneficial compounds such as neurotransmitters or short-chain fatty acids. Then there are prebiotics, substances such as certain fibres or oligosaccharides that promote the growth of “healthy” bacteria in the gut. These two areas can be combined into one food product or supplement, delivering both the beneficial bacteria and the foodstuff to help it grow in the gut. An emerging area is so-called postbiotics, which contain inactivated microbial cells or cell components, with or without metabolites, that contribute to observed health benefits. Then there are various food enzymes, bioactive proteins and peptides.

There are also a wide variety of phytochemicals including various polyphenols and polysaccharides. Many of these could be extracted from side streams from other industries, which also brings a wide range of environmental benefits including reducing waste and carbon footprints.

NI: Which bioactive molecules can be sourced from side streams?

MH: In a previous column, my colleague Guus Kortman and José Maria Pinilla of Natac Biotech talked about the OLEAF4VALUE. This is looking to identify potentially health-boosting polyphenols and triterpenoids, amongst other molecules, in olive leaf biomass from the olive oil industry. Such compounds may have anti-inflammatory, antioxidant, prebiotic or antimicrobial effects.

Earlier this year, Dutch health ingredients company NutriLeads launched an immune health ingredient based on carrot polysaccharides. This ingredient is derived from carrot pomace, which is a side stream of carrot juice production. Indeed, such potentially prebiotic polysaccharides can be found in many fruits, grains, fungi and even yeasts, and there are many efforts ongoing to find and extract polysaccharide-containing fractions from side streams of appropriate industries. For example, brewing giant AB InBev is looking at the possibility of extracting the hemicellulose arabinoxylan from brewer’s spent grain, a by-product of beer production. Arabinoxylan may boost levels of bifidobacteria in the human gut.

NI: How do we identify the actual health benefits of such compounds and probiotics?

MH: To be seen as a serious player in this market, it is absolutely essential to provide evidence that substantiates the health benefits of a new product or ingredient. The gold standard for health benefit substantiation is obviously a properly designed clinical trial. But these are costly and can take a long time to perform.

So, the first step is usually one or more in vitro studies, where the compound, microbe or product is introduced to relevant human cells (aka a model). In vitro models are an essential part of the discovery phase, helping identify new functional components and the impact of various types of processing on those components. They can also be used to provide credibility for claims that a food component is biologically active, uncover the mode of action and evaluate potential interactions between components that could either enhance or suppress the desired health benefit. What’s more, the insight gained can guide the design of later human intervention studies to increase the chances of a significant result, which saves time and money.

NI: How do you use in vitro models?

MH: In vitro models aim to mimic the conditions of a certain environment within the human body. To apply them effectively, you have to think about the type of functional component you are investigating and where it will act – then pick your in vitro model accordingly. Until recently, these models would use just one cell type, such as epithelial cells, immune cells or samples of the gut microbiota. But increasingly, people are combining different types of cells into a single model to give a more complete picture of how a food component interacts with the human body. For example, combining digestion, gut fermentation and intestinal models may give a more realistic picture of how certain peptides, oligosaccharides or other food components are metabolised and absorbed. Taking this idea further, so-called organoid models combine relevant cell types into a kind of miniaturized organ.

Choosing the right model depends on the specifics of the question you want to explore. More complex models can mimic the environment inside our bodies more realistically but take longer to deliver results. So simpler, high-throughput models are best used in early explorations when you are screening multiple or very novel components to narrow down promising candidates for further investigation. The more complex models are useful later for precise validation of previously identified components and their specific effects.

Together, these models provide the basis for identifying and validating novel compounds, microbes and products – or new benefits of existing components – to improve gut health and general wellbeing.