Phytogenics: Increased digestibility and better gut health

Phycogenics represent a fantastic opportunity to explore and discover new molecules with potential benefits on health of humans and animals, by leveraging the full potential of nature.

Dr. Stephanie Ladirat
R&D Director
NUQO Feed Additives

The market of plant extracts or so-called phytogenics emerged in the late 80’s and experienced a boom during the last decade, with the demand from consumers for more sustainable ingredients. It corresponds as well to the end of ‘black box’ solutions and the development of more transparent, advanced and innovative technologies.

With the ban of antibiotics used as growth promoters (AGP) in several regions worldwide, nutritionists have tried to use additives based on plant extracts to improve performance of broilers to the same level as AGP. If the initial intention was to use plants extracts for their antimicrobial activity, research has now shown that they have a broader range of effects on gut functions (digestion, immunity, gut structure, gut microbiota …) in the animals that can explain the observed improved performance. As of today, one can summarize the main effect of phytogenics as such:

• Modulation of microbiota composition and activity: depending on dosage, certain plant extracts can limit the growth or virulence of certain pathogens while have limited effect on ‘good’ bacteria.

• Stimulation of digestive functions: several plant extracts can increase the activity of endogenous digestive enzymes and/or influence uptake and transepithelial transport, and therefore improve nutrients digestion and absorption

• Modulation of immune response: Specific molecules can contribute to lower gut inflammation through their antioxidant activity. Other molecules can modulate cytokines production from macrophages and/or down regulate the expression genes coding for cytokine production to also keep inflammation under control or to support development of acquired immunity.

• Improvement of gut integrity: Some molecules or natural ingredients stimulate mucous production and epithelial cell proliferation and therefore contribute to the maturation and integrity of the gut structure.

The group of phytogenics covers a very wide group of bioactive molecules ‘inspired’ from Nature. If these molecules all come from a “plant”, they may come from different parts of the plant (leafy part, bark, seeds, roots, etc.). They may also be extracted using different methods ranging from simple milling and mixing to more elaborated water distillation (essential oils), alcohol extraction (tinctures) or chemically synthesized (nature-like compounds) to name few. These ingredients can have very different properties, different effects on animals, and also different purity or stability, especially for the volatile compounds. Historically, many products on the market correspond to simple mixes of ingredients, with little transparency on formulation and no protective technology to reduce volatility, denaturation or oxidation of active ingredients.

With the evolution of the market, the better understanding of animal physiology, nutritionists and formulators are now expecting a new generation of solutions: Transparency is now a must-have to exactly understand and predict efficacy in animals. Manufacturing technology must guarantee the stability and consistent efficacy of products. Finally, formulations should include innovative and exclusive ingredients, from land or marine plants.

Phytogenics are of great importance in animal nutrition, and marine macroalgae can be considered as supplements to positively influence animal performance and health parameters. Seaweeds represent a large and heterogeneous group, including brown algae (Phaeophyceae), red algae (Rhodophyceae) and green algae (Chlorophyceae). While algae are frequently studied as a source of nutrients, seaweeds possess several bioactive molecules, so called ‘phyCogenics’ (from Greek Phycos = Algae), that are studied for their prebiotic, anti-microbial, antioxidant, anti-inflammatory and immunomodulatory effects. Few examples of molecules exclusively found in marine algae are sulfated polysaccharides, phlorotannins, laminarins.

Research has shown the effects of several compounds and metabolites of interest, and their specific impact of physiology. Here is a short list of molecules or groups of molecules that have been specifically studied:
• Natural polyphenols such as phlorotannin, tocopherol, bromophenol (antioxidant activity)
• Sulfated polysaccharides or fucoidans (Immune enhancer)
• Natural pigment (to improve egg/meat colour)
• Specific complex polysaccharides (Prebiotic affect)

In a nutshell, phycogenics are not meant to replace phytogenics. They, however, represent a fantastic opportunity to explore and discover new molecules with potential benefits on health of humans and animals, by leveraging the full potential of nature.

First generations of phytogenics were often based on a simple mix of herbs or essential oils. This type of solutions, however, do not fit well with the constraints of modern feed production. The known variability of composition due to environmental factors and high loss of volatile molecules during transport, storage, feed production, etc. result in poor or at least very inconsistent effects on performance and health in animals.

‘Protective technologies’ have become a golden standard for solutions based on plant extracts or phytogenics. Different variant of coating, encapsulation or micro-encapsulation have been developed to guarantee the efficacy of products in the animal. They prevent the loss of active ingredients, also during the feed processing, and they also enable the release of active molecules exactly on spot in the digestive tract.

Recently, a company developed a new concept, based on the micro-encapsulation of phytogenics + phycogenics. This innovative solution offers a very high concentration and, as well a very good stability. Every particle contains the very same amount of active ingredients for optimal dispersion in feed and very consistent efficacy in animals.

Several trials were set to compare and validate the interest of this ‘new generation of phytogenics’, based on a transparent formulation of phytogenics and phycogenics, protected with a micro encapsulation. One of these trials was performed at the University of Berlin, and compared the effects of 2 well-known solutions found on the market, based on encapsulated phytogenics, and a new concept based on the microencapsulation of phytogenics + phycogenic. The effects were measured on performance of the birds and apparent ileal digestibility of feed at 21 days of age.

Researchers have observed that the new concept not only improved digestibility of nutrients (crude fat, crude protein and starch) but also increased digestibility of minerals (crude ash, calcium and phosphorus) as compared to the negative control (Figure 1). The other two solutions (S1 & S2) improved digestibility of some of the nutrients and/or minerals but not all and to a lower extend than the new concept.

Figure 1: The effects of various solutions on apparent ileal digestibility of nutrients (a) and minerals (b) in broilers of 21 days of age. * p<0.05

Performance results at 21 days are well in line with the observed effects on digestibility (Figure 2). The new concept, which had the strongest effects on nutrient and mineral digestibility, also had the highest improvement in performance at 21 days, with better gain (+2,2%) and improved FCR (-0,6%) as compared to the control.

Figure 2: The effects of various solutions on performance (BWG, FCR) in broilers of 21 days of age.

All in all, the new generation solution with a high concentration of protected actives had clear effects in the animals, with an improvement of feed digestibility that resulted in an improved performance.

Since the market of plant extracts emerged 30 years ago, there is now enough evidence and knowledge to understand the effects of these products, as well as the parameters that guarantee the optimal efficacy and best impact on gut health. Nutritionists can now expect solutions based on transparent formulation, that includes well-known but also innovative molecules, from land or marine plants, protected by advanced technology for stable and consistent effect. This 2nd generation of plant-based additives, based on new standard, will now replace the old generation; it represents a great opportunity for formulators and nutritionists to further invest in sustainable technologies, to better address challenges related to gut health and create more value for their customers.