Evaluation of the Effect of a Soluble Fiber Consumption on Immunity Response

Overview

At European level, the European Food Safety Agency has recognized two claims relating to the effects of prebiotics on the gastrointestinal sphere and on the immune system. In subjects aged 45-63, it was shown that a pre- and post-vaccination inulin consumption of 8g/day significantly increased the titer of antibodies directed against the H3N2 viral strain. The increase in bifidobacteria in the faeces confirmed that this effect was related to prebiotic capacities. The effect of prebiotics and probiotics on the immune response to influenza virus vaccination has been studied in two systematic reviews and meta-analyses. The authors show that the consumption of prebiotic fibers such as FOS, GOS, inulin, was also effective on the H3N2 strain, as on the H1N1 and B strains (antibody titers of 19.5%, 20.0% and 13.6% higher, respectively, compared to placebo). The soluble fiber under study is a resistant dextrin meeting the definition of a prebiotic fibre. The prebiotic properties have been demonstrated in humans in several studies for doses ranging from 10 to 20 g/day. Similarly, studies show that the effects on immune functions are favorably impacted by a consumption of 10 g/day for 8 weeks . These results confirm those of a preclinical study conducted in mini-pigs. The main objective of these study is to demonstrate that these prebiotic properties could help stimulate the post-vaccination immune response, and more specifically the production of antibodies directed against seasonal influenza viruses (following vaccination), and modulate the pro- and anti-inflammatory responses.

Screened participants who met the eligibility criteria are randomized either in the control or test (soluble fiber) group. They are asked to ingest placebo or test product at 15 g/d dosing for 60 days (2 months) . At the end of the first month (30 days) they get vaccinated against influenza virus. The effect of soluble fiber on immune response is assessed by the comparison of HI titration 30 days after vaccination between groups.