Characteristics of carbohydrates determine the shape of the gut microbiota in a chicken cecal in-vitro model

The intestinal microbiota is crucial for intestinal and overall animal health. Coccidiosis and necrotic enteritis poses significant economic burden on poultry farming. Such inflammatory intestinal diseases disrupt the gut microbiota and the addition of carbohydrates to feed can promote and sustain a stable gut microbiota. We compared the effects on microbiota composition and metabolites during fermentation of isomalto/malto-polysaccharides and high- and low methyl-esterified pectins (HMP, LMP), against a positive control, mannan-oligosaccharide (MOS), using the Chicken ALIMEntary tRact mOdel-2 (CALIMERO-2). CALIMERO-2 mimic fermentation in healthy ceca, and by spiking it with C. perfringens, we aimed to mimic fermentation in diseased chicken ceca. Pectins showed minor differences in monosaccharide composition and molecular weight. SPE8 had degree of methyl-esterification (DM) of 26 (LMP), and SPE6 and SPE7 DM of 63 (HMP). Beta-diversity was significantly similar between HMP’s SPE6 and SPE7. Bacteroidetes was dominant phylum, except for SIEM and MOS, where Firmicutes prevailed. Beneficial bacteria particularly Lactobacillus , remained stable across samples. This study advances our comprehension of the fermentability and structural impact of diverse carbohydrates on the broiler gut microbiota. Our findings underscore the potential of isomalto/malto-polysaccharides and pectins to promote intestinal health in poultry, warranting further investigations to optimize its inclusion in chicken feed.