Beta-glucans can!

This paper reports that of all immunostimulants for fish, beta-glucans  are the single most important ingredient of all. And we know that yeasts are a fantastic source of it! Beer o’clock anyone?

Journal of Fish Diseases
Volume 35, Number 2 (February 2012)
	Comparative effects of four feed types on white spot disease susceptibility and skin immune parameters in rainbow trout, Oncorhynchus mykiss(Walbaum)
	Authors:	J Xueqin 1, P W Kania 2, K Buchmann 2
	Author Affiliations:	1: School of Life Science, East China Normal University, Shanghai, China  2: Department of Veterinary Disease Biology, Faculty of Life Sciences, University of Copenhagen, Copenhagen, Denmark
	Source:	Journal of Fish Diseases, Volume 35, Number 2 (February 2012)
	Page Numbers:	127 – 135
	Available Full Text:	Full Text: Subscription Required to view full text Format: PDF Size: unknown Location: Publisher’s Site Authentication: EBSCOhost EJS
	Abstract:	The effects on rainbow trout, Oncorhynchus mykiss(Walbaum), immune parameters by differently formulated fish feed types containing immunostimulants have been tested in a double-blind, duplicated and controlled study performed over 50 days. A total of 800 rainbow trout (10–12 g) were kept in eight duplicate fish tanks (each containing 100 fish) and fed at a daily feeding rate of 1.5% of the biomass. The feed types were (1) control feed (C) without additives, (2) feed containing beta-glucan, nucleotides, manno-oligosaccharides (MOS), vitamins C and E (GNMCE), (3) feed containing probiotic bacteria and plant extracts (PP) and (4) feed with nucleotides, manno-oligosaccharides, vitamins C and E (NMCE). Plasma lysozyme activity was increased in fish fed two feed types (GNMCE and NMCE) but slightly depressed in fish fed PP. A non-significant trend for a higher mucous cell density at days 30 and 50 was shown in all fish receiving feeds with additives compared to the control group. All fish became infected with Ichthyophthirius multifiliiswhen exposed, but fish fed GNMCE showed a significantly lower infection both at days 30 and 50. Expression of genes encoding C3 and MHCII was significantly up-regulated in fish fed GNMCE for 50 days, and the expression of genes coding Hepcidin was significantly down-regulated in fish fed NMCE for 50 days. Beta-glucan was the single component, when used in combination with other feed ingredients, which was found associated with increased parasite resistance, increased lysozyme and immune gene up-regulation.
	Citation:	J Xueqin, P W Kania, K Buchmann . Comparative effects of four feed types on white spot disease susceptibility and skin immune parameters in rainbow trout, Oncorhynchus mykiss(Walbaum). Journal of Fish Diseases, Volume 35, Number 2 (February 2012), pp. 127-135, <http://ejournals.ebsco.com/direct.asp?ArticleID=4A8783A494754F6AA0F4&gt;
	URL:	http://ejournals.ebsco.com/direct.asp?ArticleID=4A8783A494754F6AA0F4