IMMUNOMODULATORY EFFECTS OF NON-DIGESTIBLE POLYSACCHARIDES – A DOUBLE-BLIND, RANDOMIZED, CONTROLLED CLINICAL TRIAL

Laue C., Soeth E., Stolte E., Enouf V., Knutsen S., Ballance S.
NOFIMA, Norway

Introduction:
Non-digestible polysaccharides were reported to have immunomodulatory properties in in vitro and clinical trials. The evidence, however, was not yet considered sufficient for substantiation of a health claim by EFSA. We aimed at assessing the immune effect in line with the guidances and opinions of the EFSA. For this purpose the effect size of 5 polysaccharides on immune parameters was assessed and the sample size for a confirmatory study was estimated in a double-blind, randomized controlled pilot trial with 6 parallel arms.

Methods:
Healthy postmenopausal woman and men (N = 239) aged ≥ 50 years maintained a low fibre diet for 7 weeks. After a wash-out period of 2 weeks, the test products were consumed for 5 weeks. Two weeks after starting consumption an influenza vaccination (2012/2013) was performed. HI titres were assessed before intervention (consumption), before vaccination and 1 and 3 weeks after vaccination. Cellular immunity was assessed before intervention, before vaccination and 1 week after vaccination by incubating full blood cells with medium, LPS, ConA and vaccine, respectively and determination of cytokine release (IL-1ß, IL-2, IL-12, IFNy, TNFα, IL-10). Respiratory and gastrointestinal infections were monitored. The test products were: Powder containing either a beta-glucan preparation from yeast (Wellmune®)(500 mg)(BG-Y), or a beta-glucan preparation from shiitake (500 mg)(BG-S), or a beta-glucan preparation from oat (Oatwell®)(10.0 g)(BG-O), or an arabinoxylan preparation from wheat (Naxus™)( 10.0 g)(AX), or an exopolysaccharide preparation from L. mucosae (2.3 g)(EXO) as well as filling substances (maltodextrins) and flavour adding up to 12.0 g altogether in sachets or only filling substances (control)(CON). The products were consumed once daily.

Results:
Geometric mean fold increase (GMFI) of HI titres differed between the interventions in Kruskal-Wallis one way analyses of variance on ranks for influenza A H1N1 (p
= 0.01), but not for A H3N2 (p = 0.198) and B (p = 0.683). Compared to control AX had higher GMFI for H1N1 (p = 0.075 in unadjusted Student t test) and BG-Y for B (p = 0.043). The increase in seroprotection rate differed between the groups for H1N1 (p = 0.003; Chi2 test) and was higher for H1N1 (p = 0.053 in unadjusted Fisher exact test) and B (P = 0.078) in AX compared to CON. Seroconversion rate differed for H1N1 between the groups (p = 0.012) and was higher for H1N1 (p = 0.062) in AX and for B (p = 0.04) in B-S compared to control. INFy differed between the groups (p = 0.013 in Kruskall-Wallis) and was higher in cells from AX versus CON (p = 0.009). The number of respiratory tract infections was lower in AX versus CON (p = 0.04; Mann-Whitney).

Discussion:
The results may indicate immunomodulatory effects by arabinoxylan and beta-glucan from yeast and shitake. The results, however, require confirmation in a pivotal trial.

Keywords: Beta-glucan, Probiotics, Arabinoxylan, Exopolysaccharides, Immunity, Respiratory tract infections

Citation:
Laue C., et al. (2016). Immunomodulatory effect of non-digestible polysaccharides – a double-blind, randomized, controlled clinical trial. Conference Proceedings of IPC2016. Paper presented at the International Scientific Conference on Probiotics and Prebiotics, Budapest (p. 40.). IPC2016

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