Impact of soybean meal enzymatic treatment on chicken caecal microbiota and intestinal epithelial cells.

As demand for sustainable and welfare-conscious food production increases, reducing the environmental and health impacts of animal feed has become a key challenge. Soybean meal (SBM) is widely used in poultry diets for its high protein content, but its richness in non-starch polysaccharides (NSPs) can hamper its digestibility. To address this issue, a common strategy involves the utilization of enzymatic cocktails rich in carbohydrate-active enzymes (CAZymes). While these feed additives are specifically designed to degrade NSPs and enhance SBM protein digestibility, only scarce information is available on their impact on intestinal health. In this study, using intestinal epithelial cells lines, we show that pre-treatment of SBM by the enzymatic cocktail Rovabio™ Advance, supplemented or not with pectin-active fungal secretomes, did not alter epithelial integrity nor induce inflammatory responses. Additionally, in vitro chicken caecal fermentations revealed that SBM was associated with a higher relative abundance of Enterobacteriaceae, while wheat fermentation was associated with Lactobacillaceae and Enterococcaceae enrichment. Enzymatic supplementation with Rovabio™ Advance further enhanced wheat fermentation and bacterial community shifts, while its effect on SBM fermentation remained limited. In contrast, SBM pre-treatment with pectin-active fungal secretomes led to significantly increased short-chain fatty acid (SCFA) production and enriched SCFA-associated genera. These findings indicate that while industrial enzyme cocktails are well suited to cereal-based diets, targeted pectin-degrading enzymes could be seen as a promising strategy to enhance the prebiotic potential of SBM. This study highlights the importance of tailoring enzymatic solutions to feed carbohydrate composition, to improve gut microbiota function and promote intestinal health in poultry. KEY POINTS: • SBM does not induce intestinal cell inflammation or epithelium disruption in vitro. • Both SBM and wheat increase SCFA production by the chicken caecal microbiota. • Pre-treatment with fungal pectin-active secretomes enhance SBM's prebiotic potential.