Wood-based lignans and polyphenols improve intestinal health by strengthening barrier integrity and reducing inflammation

Lignans and polyphenols derived from wood are known to exhibit a broad spectrum of biological activities, indicating promising potential as relevant constituents of feed supplements. We aimed to investigate two extracts derived from wood lignan-based feed additives (‘ROI’ and ‘Protect’) regarding their impact on selected parameters of intestinal functionality. The antioxidant and anti-inflammatory properties of the extracts were determined by measuring the effects on reactive oxygen species (ROS) and pro-inflammatory cytokine production in-vitro. The impact on intestinal barrier integrity was evaluated in Caco-2 cells and in Drosophila melanogaster by documenting leaky gut formations. Furthermore, feeding trials with ROI and Protect using chickens and infected piglets, respectively, were conducted. Intestinal samples of the chickens were taken to study gene expression of pro-inflammatory target genes by qPCR. Oxidative lesions recovered from the intestine of infected piglets were analyzed for the levels of superoxide dismutase, glutathione and lipid peroxidation. Protect lowered ROS production in Caco-2 cells and reversed the stress-induced weakening of barrier integrity. ROI inhibited the expression or secretion of interleukin-8 (IL-8), interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor α (TNFα) in THP-1 macrophages. Moreover, ROI decreased leaky gut formation and mortality rates in Drosophila melanogaster. ROI-fed chickens showed decreased gene expression levels for IL-1β and interleukin-8-like 2 (IL-8L2). Dietary supplementation with Protect improved the antioxidant status and barrier integrity of the intestines of infected piglets. In conclusion, wood lignan-enriched feed supplements are valuable tools that support intestinal health by exerting antioxidant, anti-inflammatory and barrier-strengthening effects. Previously published in: Heckmann et al. (2022) Molecules 27, 6327.