A polyphenol-rich extract recovered from an industrial byproduct regulates the intestinal microbiota and restricts enteric parasite infection

Dietary polyphenols have shown potential in limiting inflammation during noncommunicable diseases. However, interaction of polyphenols with the immune system and gut microbiome during enteric infections are not well defined. Moreover, efficient methods to recover high-value polyphenols from industrial processes are limited. Here, we describe the recovery of a polyphenol-rich extract from a byproduct of protein-producing biorefineries. The extract was modified to allow incorporation into a semi-synthetic mouse diet. During infection with the intestinal nematode Heligmosomoides polygyrus, mice fed the polyphenol-enriched diet had significantly lower parasite burdens and enhanced mast cell–related gene expression in the jejunum, potentially accelerating worm expulsion. Effects on the gut microbiome were dependent on infection status. In uninfected animals, the extract significantly reshaped the gut microbiome by expanding a broad range of short-chain fatty acid (SCFA)-producing bacteria. However, during H. polygyrus infection, its modulatory effect on the microbiome was markedly diminished concomitant with an extensive increase in the abundance of the Lactobacillaceae and Enterobacteriaceae families in infected mice. However, the extract reduced the relative abundance of Clostridiaceae during infection, suggesting a role in restoring gut homeostasis by counteracting parasite-induced expansion of potentially pathogenic bacteria. Collectively, these findings demonstrate that byproducts from the biorefining industry can be repurposed as functional food components with the potential to limit enteric infection and inflammation.