Metagenomic analysis revealed the interaction between the gut microbiota of healthy lambs and diarrheal lambs and the host's immunity

Diarrhea poses a significant threat to the health and welfare of lambs, causing high morbidity and mortality rates, and resulting in serious economic losses to the goat farming industry. Although many diseases are related to the gut microbiota, little is known about how diarrhea affects the gut microbiota of young goats. So we used sequencing to construct the intestinal microbiota-immune interaction network of healthy and diarrheal lambs. This study aims to explore the associations between diarrhea and microbial community structure, specific bacterial genera, and immune changes. The results show that the diversity of diarrheal lambs is reduced compared with healthy lambs. Principal coordinate analysis showed that there were significant differences in the distance matrix of the intestinal microbiota between healthy lambs and diarrheal lambs. At the phylum level, Firmicutes, Proteobacteria and Bacteroides are the dominant phylum of young goats. At the genus level, Escherichia_Shigella was predominant in diarrheal lambs, and the proportions of [Ruminococcus]_gnavus_group and Clostridium_sensu_stricto_1 increased. The proportions of Bacteroides and Fournierella decreased. Further analysis using random forest indicated that Escherichia_Shigella, Bacteroides and Fournierella could be used as markers for predicting the occurrence of diarrhea. Compared with healthy lambs, pro-inflammatory factors in diarrheal lambs were significantly upregulated. To sum up, our results indicate that dysbiosis of the intestinal flora may be an important driver of diarrhea in lambs. The significant increase in the abundance of Escherichia_Shigella and the decrease in the abundance of Bacteroides and Fournierella may become important causes of diarrhea in young goats.