Nowadays, consumers are more health-conscious than ever and take a holistic approach when it comes to their health and wellbeing – with gut health and immunity being top of mind1. In line with this trend, prebiotic fibres have received increasing attention because of their numerous recognized health benefits. Prebiotic fibres are non-digestible carbohydrates, meaning that they can resist digestion in the upper gastrointestinal tract. After reaching the colon, prebiotics undergo complete or partial fermentation and selectively stimulate the growth and activity of beneficial members of the gut microbiota2.
As consumers' awareness and understanding of the gut microbiome's crucial role for health and wellbeing continues to grow, exciting opportunities are available to the nutraceutical industry to use new types of prebiotics for delivering microbiome-based health benefits.
The global prebiotic food and supplement market is anticipated to rise at a considerable rate during the next years and may reach $8.5 billion by 20263. Currently, this market is dominated by a limited range of prebiotics, with dairy-based galactans and inulin top-ranked. Inulin has been studied frequently and is considered the "gold standard" in this field. However, there are some limitations with these types of prebiotics since they are fermented at a rapid rate in the gut, without having the time to reach the distal colon, the most critical "target" for gut health4. Moreover, rapid fermentation leads to gas formation with bloating as an unpleasant side effect.
Why arabinoxylans from wheat endosperm?
Arabinoxylan (AX) extracted from wheat endosperm is a novel, exciting prebiotic recently launched by Bioactor under the brand NAXUS.
NAXUS is an extract from wheat endosperm – the most nutritious part of the wheat kernel - and composed of major non-starch, non-digestible polysaccharides, primarily β-(1,4)-linked d-xylopyranosyl residues to which arabinose side chains and ferulic acid moieties are attached. Due to the high molecular weight (up to 500 kDa), chain length and complex branched structure, NAXUS is gradually and selectively fermented along the entire colon by specific intestinal bacteria – possessing AX-degrading enzymes4.
The main difference between arabinoxylan derived from the endosperm and arabino-xylo-oligosaccharides (“AXOS”) derived from the bran, is the chain length (also referred to as Degree of Polymerization (“DP”) and fermentation pattern. DP is an important aspect when it comes to the functionality, health benefits, and tolerability of these molecules. NAXUS, coming from the wheat endosperm has a high DP (>30) and is therefore slowly fermented. It thus has a greater chance to interact with different beneficial bacteria, so that their biological activity can last longer as they require a longer time to be degraded5.
NAXUS showed strong bifidogenic activity in multiple studies, whereby Bifidobacterium longum is particularly stimulated2,6. Interestingly, it appears that wheat-AX molecules are utilized by cross-feeding Bifidobacteria and butyrate-producing colon bacteria, such as Faecalibacterium prausnitzii (clostridium cluster IV) and, Roseburia species (clostridium cluster XIVa), leading to butyrogenic effects7.
Among the many health benefits prompted by the strong prebiotic activity and short-chain fatty acids (SCFAs) production, it was demonstrated that NAXUS plays an important role in strengthening the innate and adaptive immune system8, reducing gut permeability9 as well as improving the metabolic control via several distinct mechanisms. An EFSA health claim has been also authorized for this ingredient because of its ability to systemically reduce the post-prandial glucose level10.
Wheat arabinoxylan and inulin: head-to-head or hand-in-hand?
Extensive available research demonstrates that different types of prebiotic fibres stimulate specific gut bacterial growth. For this reason, a combination of different prebiotics can be a successful strategy to improve overall gut health and wellbeing.
Bioactor and its research partners investigated the different prebiotic effects on the intestinal microbiota of NAXUS and inulin through different in vitro models and randomized placebo-controlled clinical trials.
Notably, the prebiotic effects of NAXUS and inulin were compared in both the SHIME and TIM-2 models, well known simulators of the human gut. It was demonstrated that both NAXUS and inulin increase the formation of health-promoting short-chain fatty acids (SCFA), while stimulating the growth of different Bifidobacterium. Specifically, while inulin stimulated the Bifidobacterium adolescentis, NAXUS promoted the growth of Bifidobacterium longum4.
These results were consistent with the results obtained in a randomized, double-blind placebo-controlled clinical trial. The study included 60 healthy participants randomly assigned to three groups, receiving either: 5 g of NAXUS; 1 g NAXUS + 3 g inulin; or a placebo for 4 weeks. Interestingly, the researchers reported: "The association of inulin and NAXUS (3 and 1 g/day, respectively) appears to be more efficient than inulin used at higher doses". Besides, it was also demonstrated that the combination of NAXUS and inulin decreases the lipopolysaccharides (LPS) concentration in blood and modulates cytokines' gene expression, reducing the levels of inflammation6.
Since inulin – at higher doses – leads to bloating, partially replacing inulin by NAXUS at a 4-fold lower dose, offers a good opportunity to obtain an overall more potent prebiotic effect without intestinal discomfort.
Opportunities for dietary supplement and functional food industry
As consumers are looking for natural products which will enhance their gut health and immunity, NAXUS is potentially the next go-to prebiotic on the market.
Prebiotic effects throughout the colon, including distal colon area, have been an important goal of next- generation gut health products. NAXUS on its own, or together with other prebiotics such as inulin, can be a good strategy to achieve health promoting effects along the entire colon, whilst significantly reducing potential unpleasant side-effects.
BioActor and its scientific partners generated a wealth of data on the gut health effect, immunomodulatory activity and metabolic control of arabinoxylan from wheat endosperm. The proven efficacy of NAXUS as a prebiotic targeting immunity, together with the authorized health claim on the glycaemic control, offer great opportunities for applications in dietary supplements and functional foods such as healthy snacks, dairy, plant-based options and many more.References
1. FMCG Gurus’ ‘The Impact of Immunity – Global Report 2020 (9)
2. Neyrinck AM, Possemiers S, Druart C, et al Prebiotic effects of wheat arabinoxylan related to the increase in bifidobacteria Roseburia and Bacteroides/ Prevotella in diet induced obese mice PLoS One. 2011;6(6):e20944.
4. Van den Abbeele P, Venema K, Van de Wiele T, Verstraete W, Possemiers S. Different human gut models reveal the distinct fermentation patterns of arabinoxylan versus inulin. Journal of agricultural and food chemistry. 2013 Oct 16;61(41):9819-27.
5. Chen Z, Li S, Fu Y, Li C, Chen D, Chen H. Arabinoxylan structural characteristics, interaction with gut microbiota and potential health functions. Journal of Functional Foods. 2019 Mar 1;54:536-51.
6. Lecerf JM, Dépeint F, Clerc E, Dugenet Y, Niamba CN, Rhazi L, Cayzeele A, Abdelnour G, Jaruga A, Younes H, Jacobs H. Xylo-oligosaccharide (XOS) in combination with inulin modulates both the intestinal environment and immune status in healthy subjects, while XOS alone only shows prebiotic properties. British Journal of Nutrition. 2012 Nov;108(10):1847-58.
7. Rivière A, Selak M, Lantin D, Leroy F, De Vuyst L. Bifidobacteria and butyrate-producing colon bacteria: importance and strategies for their stimulation in the human gut. Frontiers in microbiology. 2016 Jun 28;7:979.
8. Fadel, A, Plunkett, A, Li, W, et al. Modulation of innate and adaptive immune responses by arabinoxylan. J Food Biochem. 2018; 42:e12473.
9. Salden BN, Troost FJ, Wilms E, et al Reinforcement of intestinal epithelial barrier by arabinoxylans in overweight and obese subjects. A randomized controlled trial. Clin Nutr 2018 37 2 471 480.
10. Scientific Opinion on the substantiation of health claims related to arabinoxylan produced from wheat endosperm and reduction of post-prandial glycaemic responses (ID 830) pursuant to Article 13(1) of Regulation (EC) No 1924/2006