Microalgae as feed ingredients: recent developments on their role in immunomodulation and gut microbiota of aquaculture species

Microalgae are rapidly evolving alternative ingredients in food and feed. Desirable nutritional and functional qualities make them high potential sources of feed ingredients. Certain microalgae species are known to accumulate large amounts of protein, containing all essential amino acids while some species contain essential fatty acids and bioactive compounds hence offering several possible health benefits. However, successful inclusion of microalgae-based products in feed requires a clear understanding of physiological responses and microbiota of animals receiving microalgae diets. In this review, key microalgae-based feed ingredients and their effect on gut microbiome and immunomodulatory responses of microalgae fed animals, with a focus on aquatic species will be discussed.