Gum Arabic (Acacia senegal) enhances reproduction and modulates the microbiota-gut-brain axis of zebrafish in a sex-specific and dosage-dependent manner

Abstract

Dietary fibres (DFs) constitute a wide range of heterogeneous compounds that resist digestion and have beneficial effects on general health. Gum Arabic (GA) is a tree exudate consisting of 90% arabinogalactan, a polymer of arabinose and galactose sugars with prebiotic properties. As a dietary fibre, GA improves renal function, metabolism, and immune response in humans and animals. However, the underlying mechanisms leading to these health benefits are poorly understood. We supplemented female and male zebrafish (Danio rerio) with two concentrations of GA (6% and 60%) for two weeks. We assessed the effects of GA supplementation on the gut microbiome composition, intestinal and brain metabolic profiles, reproductive fitness, and brain gene expression. We found that GA supplementation resulted in changes to the gut microbiome with a relative increase in Fusobacteria and a relative decrease in Proteobacteria where the beneficial genusCetobacteriumwas significantly more abundant after supplementation. GA supplementation increased acetate levels, particularly in the brain, causing a decreased expression of cart1 in the brain of female zebrafish. While GA supplementation increased overall activity in male and female fish, reproductive fitness was negatively affected by GA supplementation in females. Our results suggest that while GA supplementation may have positive effects on metabolic rate and overall activity, it may come at a trade-off with reproductive fitness.