Gum Arabic modulates the microbiota-gut-brain axis and affects general fitness in zebrafish

Abstract

Gum Arabic (GA) (Acacia senegal var. senegal) is an edible tree exudate and dietary fibre shown to improve health in humans and animals. We tested the ramifications of GAon organismal health across the microbiota-gut-brain axis by supplementing female and male zebrafish (Danio rerio) with two concentrations(6% or 60%) of GA (Acacia senegal var. senegal) for two weeks. We assessed the effects on the gut microbiome composition, intestinal and brain metabolic profiles, reproductive fitness, locomotion, and brain gene expression. GA supplementation induced a relative decrease in Proteobacteria and a relative increase in Fusobacteria, with a rise in the beneficial genus Cetobacterium. In the GA-supplemented fish, we detected increased intestinal glucose metabolism, evidenced by reduced glucose retention levels. Additionally, high levels of acetate were detected in the brain. Interestingly, the gene cart1, involved in appetite and hunger control, was significantly downregulated in female brains only. Consistently, we detected increased locomotion in GA-supplemented fish compared to Control fish. Interestingly, GA supplementation had a negative effect on female reproductive fitness and a positive effect on male reproductive fitness.Our results emphasise the significance of evaluating the impact of dietary fibre at a systemic level to develop relevant nutritional guidelines that consider the different nutritional requirements of each sex.