The gut microbiome promotes the growth performance of black soldier fly larvae by degrading uric acid

The black soldier fly (BSF) has garnered great interest as a sustainable protein source for food and feed globally. However, various toxins can adversely affect the growth performance of BSF larvae, and the underlying mechanisms by which these larvae tolerate or detoxify such compounds remain largely unexplored. In this study, we report that uric acid (UA) exerts detrimental effects on BSF larval development and that the gut microbiota plays a crucial role in facilitating their host tolerance to this stress. Our findings reveal that BSF larvae produce substantial amounts of UA as a terminal product of nitrogen metabolism. Importantly, we observed that UA significantly impairs both larval growth and the bioconversion efficiency of BSF. Deep sequencing analysis showed that UA exposure induces a notable shift in the composition of the gut microbial community. Furthermore, microbiome depletion exacerbates the negative impact of UA on larval growth and bioconversion, and UA-degrading bacteria specifically confer host resistance to UA toxicity. Additionally, UA-degrading bacteria effectively elevate larval growth and bioconversion rates in the context of chicken manure management. Taken together, our findings demonstrate that the gut microbiome promotes BSF larval growth through UA detoxification, highlighting a novel and promising application of UA-degrading bacteria as probiotics to optimize BSF larval mass production.