Exploratory study on interaction between bacteria and fungi from mulberry to intestine of Bombyx mori

Abstract Many kinds of antibiotics in the environments deeply affect the microbial composition, but their effect on the interactions among the host microbiota is still poorly understood. This study used Bombyx mori as the model organism by feeding the antibiotics-treated mulberry leaf, preliminarily explored the effects of antibiotic exposure on the interaction of bacteria and fungi in the worm’s intestine. Our results showed that the elimination of fungi significantly reduced the bacterial richness and diversity in the worm’s intestine after exposure of anti-fungal amphotericin B, while the elimination of bacteria dramatically increased the richness and diversity of fungi after exposure of anti-bacterial ampicillin-streptomycin. The results revealed the intestinal bacteria and fungi of Bombyx mori were markedly shaped by the mulberry leaf flora. Anti-bacterial antibiotics enhanced the correlation between the host gut fungi and the diet-deriving fungi, while anti-fungal antibiotics weakened the correlation between the host gut bacteria and the diet-deriving bacteria. The data preliminarily established a simple model to explore the effect of antibiotics on the host microbiota interactions, and provided a way for further study on the environmental factors of intestinal bacteria-fungi interaction.