An overview of extraction and purification techniques of seaweed dietary fibers for immunomodulation on gut microbiota

Background: Nutritional well-being is the prerequisite condition for a sustainable improvement in human wel- fare. Human gut microbiota plays a magnificent role in balancing the condition of metabolic syndrome man- agement. Currently, the gut microbiome mediated immune system is gaining attention for the treatment of several health ailments such as diabetes, gastrointestinal disorders, and malnourishment. Bioactive compounds from marine polysaccharides from seaweeds are found beneficial for enhancing the activity of gut microbes. Scope and approach: There were limited reviews in recent times to discuss the updates on extraction, purification and biological activities of dietary fibers using non-conventional methods. The present review inspects on the proximal and structural composition of seaweed polysaccharides and their methods of extraction and pur- ification aspects. It also focuses on the immune modulating mechanisms of prebiotic-probiotic synergetic in- teraction by stimulating beneficial gut microbial activity and by the production of short-chain fatty acids. The mutual relationship between prebiotics and probiotics that leads to a healthy gut was targeted in the present review.

Key findings and conclusions: Marine seaweeds polysaccharides are the untapped bioresources to be explored for its biotherapeutic properties of dietary fibers. The practical complications on extracting polysaccharides by a single technique could be overcome by adopting the strategy of utilizing combinatorial extraction and pur- ification techniques. Its prebiotic effect aids in the enhancement of gut microbial activity by exhibiting the properties of non-digestibility, fermentability, and pathogen inhibition potential. The impending benefits of dietary fiber from seaweed polysaccharides as prebiotics for formulating functional food ingredients along with probiotic microbes to exhibit immunomodulation applications. Therefore, intended human clinical trials should be carried out to evaluate and discover the probiotic-prebiotic relationship in the human gut, which could step out the research to the next level in the medicinal world.