The Protective Effects of Microbe Derived Antioxidants on Digestive Tissue Morphology, Functions, and Intestinal Microbiota Diversity of Eriocheir sinensis Exposed to Glyphosate

Introduction: The use of glyphosate (Gly) has caused unnecessary economic losses to the aquaculture industry, but research on the effect of Gly on Eriocheir sinensis is very limited. The aim of this study is to reduce the negative effects of Gly, reduce yield loss, and improve economic benefits through nutritional feed control technology.

Methods: The experiment involved 80 crabs randomly divided into four groups: control group, Gly group (48.945 mg/L), microbe-derived antioxidant (MA) group, and Gly and MA treatment group. The study lasted for 7 days. In this study, the effects of Gly on the digestive function of E. sinensis were investigated using histology and spectrophotometer, and the gut microorganisms of E. sinensis were analyzed using high-throughput sequencing technology.

Results: The study found that exposure to Gly resulted in separation of the folds of the midgut mucosa of Eriocheir sinensis from the basement membrane, a decrease in the fold area of the hindgut mucosa, and an increase in the number of B cells in hepatic tubules. Additionally, the lipase activity of the intestine in the Gly group was significantly higher than that of the control group and the MA + Gly group, while the hepatopancreatic lipase decreased significantly. The amylase activity in the intestine and hepatopancreas of the Gly group was significantly lower than that of the control group. The trypsin activity in the hepatopancreas of the MA + Gly group was significantly higher than that of the Gly group. The Shannon diversity index in MA + Gly group was significantly lower than that in control group. At the phylum level, the abundance of the Campilobacterota in the MA + Gly group decreased. At the genus level, the proportion of the Citrobacter and Flavobacterium in the MA + Gly group decreased.

Conclusion: Gly has certain effects on the digestive tissue function, intestinal microbial diversity index and intestinal microbiota structure of E. sinensis, and MA can ameliorate the negative effects of Gly on E. sinensis.