<unk> s are polysaccharides that only contain glucose as structural components.<unk>  1, 3-D<unk> s are chains of D-glucose molecules, with the six-sided D-glucose rings connected at the 1 and 3 positions.  Smaller side chains branch off the 1,3 polysaccharide “backbone.” The most active form of<unk>  1, 3-D<unk> s are apparently those that contain 1,6 side-chains branching off from the longer<unk> -1,3<unk>  backbone.  These are referred to as<unk> -1,3/1,6<unk> . Some researchers have suggested that it is the frequency, location, and length of the side-chains rather than the backbone of<unk> s that determine their immune system activity.  Another variable is the fact that some of these compounds exist as single strand chains, while the backbones of other<unk> -1,3<unk> s exist as double or triple stranded helix chains.  In some cases, proteins linked to the<unk> -1,3<unk>  backbone may also be involved in providing therapeutic activity.  Although these compounds have exciting potential for enhancement of the immune system, it must be emphasized that this research is in its infancy, and there are differing opinions on which molecular weight, shape, structure, and source of<unk> -1, 3<unk> s provide the greatest therapeutic benefit.
One of the most common sources of<unk>  1, 3-D<unk>  is derived from the cell wall of baker’s yeast (Saccharomyces cerevisiae). However,<unk> -1,3<unk> s are also extracted from the bran of some grains such as oats and barley.  The<unk>  1, 3-D<unk> s from yeast are often insoluble whereas those extracted from grains tend to be soluble.  Other sources include some types of seaweed , and various species of mushrooms such as Reishi, Shiitake, and Maitake.<unk>  1, 3-D<unk> s are being referred to as biological response modifiers because of their ability to activate the immune system. However, it should be noted that the activity of<unk>  1, 3-D<unk>  is different from agents that stimulate the immune system. Agents that stimulate the immune system can push the system to over-stimulation, and hence are contraindicated in individuals with autoimmune diseases, allergies, or yeast infections. <unk>  1, 3-D<unk> s seem to make the immune system work better without becoming overactive. They accomplish this by activating phagocytes, which are immune system cells whose function is to trap and destroy foreign substances in our bodies such as bacteria, viruses, fungi, and parasites. In addition to enhancing the activity of phagocytes,<unk> -1,3<unk> s also reportedly lower elevated levels of LDL cholesterol, aid in wound healing, help prevent infections, enhance NK cell function, and help in the prevention and treatment of cancer.
Beta-glucan
Muconic acid
Lecithin
Hypromellose
Heparan sulfate
Chitosan
Monosaccharide
D-Galacturonic acid