Metabonomic Analysis of Silkworm Midgut Reveals Differences between the Physiological Effects of an Artificial and Mulberry Leaf Diet

Abstract

Bombyx mori is a model lepidopteran insect of great economic value. Mulberry leaves are its only natural food source. The development of artificial diets can not only resolve the seasonal shortage of mulberry leaves but also enable changes to be made to the feed composition according to need. Metabolomic differences between the midguts of male and female silkworms fed either on fresh mulberry leaves or an artificial diet were studied using liquid chromatography–mass spectrography (LC-MS/MS) analysis. A total of 758 differential metabolites were identified. Our analysis showed that they were mainly involved in disease resistance and immunity, silk quality, and silkworm growth and development. These experimental results provide insights into the formulation of optimized artificial feed for silkworms.

Gut Microbiota Analysis in Silkworms (Bombyx mori) Provides Insights into Identifying Key Bacterials for Inclusion in Artificial Diet Formulations

“…The enhanced species richness observed in the SL group could be attributed to the multitude of components integrated into the artificial diet, including soybean meal, corn powder, and an assortment of nutritional additives. These components collectively foster a more diverse microbial community [5,6,12,16]. However, it is crucial to recognize that a higher microbial diversity does not automatically equate to superior host performance.…”

“…The nutrient composition of mulberry leaves, particularly the balance of proteins, carbohydrates, and essential micronutrients, plays a pivotal role in the growth, development, and silk production of silkworms [4,8,9]. However, the increasing demand for silk and the need for cost-effective and efficient production methods have led to the widespread adoption of artificial diets in commercial sericulture [6,[10][11][12]. These formulated feeds, often based on a combination of soybean meal, corn powder, and various nutritional supplements, aim to provide a balanced and easily digestible nutrient profile for optimal silkworm growth [11,12].…”

“…However, the increasing demand for silk and the need for cost-effective and efficient production methods have led to the widespread adoption of artificial diets in commercial sericulture [6,[10][11][12]. These formulated feeds, often based on a combination of soybean meal, corn powder, and various nutritional supplements, aim to provide a balanced and easily digestible nutrient profile for optimal silkworm growth [11,12]. Although artificial diets have bolstered productivity and lessened the industry's dependence on mulberry farming, they have also engendered novel challenges concerning the health of silkworms and the caliber of silk produced [13][14][15].…”

Effects of Habitual Dietary Change on the Gut Microbiota and Health of Silkworms

“…For silkworms, MLs are considered the most suitable diet, whereas AD is a nutritionally imbalanced diet [16,36]. Studies have shown that the dietary pattern of MLs shapes the formation of similar and stable gut microbiota among individual silkworms and is crucial for their health [28].…”

“…In order to improve production efficiency, modern sericulture has gradually started using artificial diets (ADs) as a substitute for MLs in silkworm rearing [15]. However, silkworms fed on ADs exhibit significantly diminished robustness and silk production efficiency [16,17]. Studies using mice and other models have revealed that a high-fat diet (HFD) or high-sugar diet (HSD) significantly affects the composition and function of the gut microbiota, thus impairing the host's metabolic homeostasis [18,19].…”