Food proteins and bioactive peptides as nutraceutical intervention against immune system disorders: a review

Diets have been shown to influence the immune system, and food proteins and their bioactive peptides (FBaPs) are gaining scientific attention as immunomodulators. FBaPs elicit their immunomodulatory properties by interacting with receptors, such as Toll-like receptors (TLRs), to initiate signal transduction through transcription factors, including nuclear factor-kappa beta (NF-κB), and mitogen-activated protein kinase (MAPK) signaling pathways. This leads to the activation of macrophages and dendritic cells (DCs), stimulation of splenocytes and natural killer (NK) cells, and increased expression of cytokines, immunoglobulins, and phagocytosis, as reported in several in silico, in vitro , and animal studies. Modulation of gut microbiota population and promotion of intestinal health are characterized by an increase in beneficial microbes and a decrease in pathogenic microbes, an improvement in intestinal mucosal integrity, a decrease in mucosal permeability, and an enhancement of immune system function. Studies on the immunomodulatory properties in human subjects and robust safety evaluation of FBaPs are limited, warranting further investigation. This review discusses the current knowledge on the potential application of bioactive peptides derived from proteins of diverse sources, including plants, microbes, animals, and marine organisms, as immunomodulators. It also provides a comprehensive understanding of the safety and challenges associated with their clinical applications, as well as future research directions to inspire further research and fill the identified knowledge gaps. • Yellowfin tuna, Monkfish, Oysters, egg yolk, Lupine, and Nile tilapia contain immunomodulatory peptides (IBaPs). • IBaPs modulate the immune system by upregulating immunoglobulins and proliferation of NK cells, T-cells and splenocytes. • IBaPs increase beneficial gut microbiota and decrease pathogenic gut microbiota • IBaPs modulate immune response via TNF-α, NF-κB, and MAPK signaling pathways