A Review on the Impact of the Plant Bioactive Compound <i>β</i>-Glucans as Phytochemicals for Boosting Human and Animals’ Immune Response—<i>β</i>-Glucans as Immunostimulants

The influence of food and nutrition on health and immunity for both human and animals are being demonstrated. Phytochemicals are natural compounds present in cereals, beans, fruits, vegetable, and other plants, believed to enhance immune response for both human and animals. One of these phytochemicals is β-Glucans that are heterogeneous polysaccharides consisted of branched long chains of D-Glucose units present in cereals such as barley, wheat, and oats, and also present in microbial cell walls for yeasts, fungi, bacteria, and algae. β-Glucans extracted from cereals and mushroom were investigated for their positive impact on immunomodulation for both human and animal health. These β-Glucans proved to enhance immune system for innate response as the first defense against microbial infection, toxins, and self-tumor cells, and also, enhance adaptive immune that also referred to specific immunity as the second defense in response to antigen-specific lymphocytes against microbial infection, toxins, and self-tumor cells.