This 2018 rodent study compared and contrasted commercially available β-glucans:

“β-glucans are natural biologically-active compounds called ‘biological response modifiers.’ This study is a follow-up of our three previous studies that tested 43 different glucans.

We used 16 different glucans isolated from yeasts, mushrooms, algae, and oats. We compared their effects on phagocytosis, IL-2 production, antibody secretion, and inhibition of three experimental cancer models.

Our results showed significant differences among tested glucans, despite the fact that glucans in general have strong stimulating effects on most aspects of the immune system. Differences between activities of commercially available glucans might be an explanation for the sometimes confusing results found in the literature. In all tests employed, Glucan #300 was the most active.

Highly purified and active glucans have significant pleiotropic effects.”

https://www.researchgate.net/publication/323523231_Glucans_and_Cancer_Comparison_of_Commercially_Available_b-glucans_-_Part_IV “Glucans and Cancer: Comparison of Commercially Available β-glucans – Part IV” (registration required)