(a)

Once swallowed, whole beta glucan particles pass through the stomach into the small intestine where they are taken up by specialised regions called Peyer’s Patches. 

In the Peyer’s Patches, the beta glucan molecules are encountered by circulating macrophages – immune cells whose function is to engulf and digest invading micro-organisms.

Macrophages have receptors which specifically recognise beta 1,3-1,6 glucans (1), because this compound occurs in the cell walls of yeasts and fungi. When you ingest beta glucan your innate immune system ‘thinks’, not unreasonably, that an enemy has arrived and it rise to the challenge. This important first line of defence is now fully activated, and several well-conducted research papers have shown that resistance to infection is greatly enhanced (2).

Specialised cells called M-cells transport the whole glucan particles to macrophages which then convey them to various regions of the immune system such as lymph nodes and bone marrow.

The macrophages break down the beta 1,3-1,6 particles into smaller particles, and release them over a period of 24 to 36 hours.

References

1 Czop & Austen '85

2 Onderdonk et al ’92, Kernodle et al '98, Vetvicka et al '02