Comparative analysis of gut bacterial communities in housefly larvae fed different diets using a high-throughput sequencing approach.

Housefly larvae are a synanthropic host for various bacteria, including pathogens and commensals and an important protein source for monogastric animal feed. Many factors, such as diets, life stages, host habitats can influence microbial community structure. In this study, the diversity of bacterial communities in the gut of housefly larvae fed on different artificial diets was comprehensively characterized using high-throughput sequencing with the aim shedding light on an optimal larval diet. The results showed that the dominant bacteria belonging to Proteobacteria, Firmicutes and Bacteroidetes phyla were related to polysaccharide degradation. The comparative analysis indicated that the dominant intestinal bacteria of larvae fed on high-protein were similar to those on high-fat diet. The same was the case in larvae fed high-starch diet and wheat bran alone. In addition, the diversity of intestinal bacteria at genus level in larvae fed high-protein and high-fat diet was higher than in larvae fed the other two diets. Further analysis indicated that the increase of potential commensals and decrease of pathogens in larvae fed on high-fat diet contributed to the increase of housefly larvae immunity. It established a foundation for further research on improvement of nutrition of housefly larvae used for poultry and fish feed.