Effect of Gum Arabic supplement on Zebrafish gut microbiota and reproduction
A whole-food, plant-based diet rich in fruits and vegetables in addition to whole grains and legumes is highly praised for its positive health benefits. A reason for that is the high content of dietary fibres that are essential for optimal health and well-being. However, most people in the UK do not meet the minimum daily intake of at least 30 g. Gum Arabic (GA), a safe and rich source of soluble fibre, could potentially be incorporated into a typical Western diet as more evidence-based research confers its positive impact on health. To elucidate the mechanisms of action of GA's role in health improvement, we combined bioinformatics (RNA-seq and 16S rRNA microbiome analysis) with metabolomics in combination with the zebrafish (Danio rerio) model. The results of this study show that a two-week diet consisting of 60% GA can significantly (adjusted p-value < 0.05) alter the expression levels of three genes related to appetite control and neuroprotection in the zebrafish brain. Our analysis also shows that incorporating GA into the diet affects the structure of the microbiota. It induces a variation in richness and bacterial taxa abundance by reducing microbiome alpha diversity and increasing the similarity in the microbial structure of the treated samples which is suggestive of a possible strain-specific selectivity mechanism. Overall, the significance of this report lies in its ability to underscore the importance of dietary fibre on health but specifically the role of GA as a prebiotic and a promising dietary soluble fibre in the context of the gut-microbiota-brain axis. Overall design: Adult zebrafish were housed in standard conditions and had their diet supplemented with Gum Arabic, at either 6% or 60% doses. They were housed in equal sex-ratios and then out-crossed for breeding to see if there was an impact on fertility.