F
Supporting gut health with seaweed extracts: A targeted approach
G
ut health has become increasingly important in the livestock industry with the emergence of antimicrobial resistance and the urge to limit the use of antibiotics. The intestinal mucosa converges various functions: digestion and absorption of nutrients; as well as physical barriers against microbes and toxins, thanks to the presence of a protective mucus layer and tight junction proteins that seal the paracellular space. The intestinal mucosa hosts both gut microbiota and immune cells (70% of the total number of immune cells are residents of the gut mucosa and gut-associated lymphoid tissue). In modern production systems, the gastrointestinal tract is being challenged and the subtle gut health balance being relied on can be impaired. The components that define gut barrier and immune function can be weaken and lead to higher occurrence of digestive troubles associated with dysbiosis. This disbalance will trigger local and systemic inflammation, affecting the global health status and the growth performance of the animals. The challenge in the industry is to find solutions capable of supporting the epithelial barrier function and the gut-associated lymphoid tissue (GALT), in order to maintain a proper gut health and, thus, ensure good performance without the need of antibiotics.
Seaweeds: The multi-asset solution!
Many candidates are available, with varying efficacy and scientific evidence. Among them, seaweeds, or macroalgae, which have gained great interest in the past decades and are the object of increasing research. In the literature, seaweeds are being ascribed a wide range of biological activities, such as immunomodulating, antioxidant, antiviral or antihyperlipidemic properties. Seaweeds are divided into three groups: brown, red and green algae. Despite their phylogenetic differences, seaweeds share the specificity of their parietal polysaccharides. Their structural complexity and unique composition make them very reactive and explain their biological activities towards animals, plants and humans. The complexity and reactivity of seaweed polysaccharides derive from the nature of the sugar units, which are diverse and sometimes rare. Like uronic acids, xylose and rhamnose, the variety of glycosidic bonds leading to their branched structure and the presence of sulfate groups (see Figure 1). Furthermore, their polyanionic structure and solubility increases their reactivity and facilitates their recognition by host cells. The main types of seaweed polysaccharides are agar and carrageenans (red seaweeds), ulvans (green seaweeds) and fucans (brown seaweeds), each of them presenting specific molecular traits which determine their biological properties and reactivity.
Figure 1 - Seaweed polysaccharides structure
66 | April 2019 - Milling and Grain