In vitro batch fermentation by-products
Nutritional management is a promising strategy to alleviate intestinal disorders around weaning in pig production. By-products from the agro-industrial sector are major sources of dietary fibres suitable for livestock feeding and could represent potential prebiotic candidates to modulate beneficial microbiota populations. In the present study, chicory root and pulp, citrus pulp, rye bran and soybean hulls were tested in an in vitro batch fermentation model for their microbiota-modulating capacities in comparison to inulin, considered as positive control. The microbiota composition in the broths after 12 and 24 hours of fermentation was analysed using 16S rRNA gene sequencing. No changes in the phylum Bacteroidetes were detected at 12 and 24 hours. Significantly higher relative abundances of the Firmicutes phylum were found with inulin after 12 and 24 hours, although it did not differ from chicory root after 12 hours. Enriched Eubacterium spp., Enterococcus spp., Ruminococcus spp. and unclassified Erysipelotrichaceae levels were found for both ingredients at 12 and 24 hours. These genera were positively correlated with butyrate production after 12 and 24 hours. We can therefore suppose that inulin and chicory root supplementation enriched the Firmicutes phylum by stimulating butyrate-producing bacteria in vitro.