Effects of anti-inflammatory and digestive-promoting fermented Chinese herbs on cecum microbiota composition and content metabolome of Chinese chickens ( Gallus domesticus )

Abstract

In this study, 168 chicks were randomly divided into two groups to elucidate the effect of fermented Chinese herbs (FCHs) on the intestinal microbiota of Chinese chickens (Gallus domesticus) and provide a scientific basis for the development and application of FCHs feed additives. The chicks were fed a basal diet for 7 days during the pre-feeding period. Thereafter, the control group was fed a basal diet, and the experimental group was fed a basal diet supplemented with 1.5% FCHs for 43 days. After being weighed and euthanised, the chickens were dissected to obtain the caecum content to analyse the intestinal microbiota composition using high-throughput sequencing of the 16S rRNA gene and metabolites using ultra-high-performance liquid chromatography high-resolution mass spectrometry. Our results showed that FCHs had no effect on the growth and serum immunological indices of Chinese chickens but significantly increased the bursa of Fabricius index, and reduced the α-diversity and affected composition of the caecum intestinal microbiota. In particular, the relative abundance of Akkermansia increased, and these of Bacteroides, Megamonas, and Faecalibacterium were reduced, accompanied by a change in the composition of caecal metabolites. These results implied that the FCH probably enhance the immune capacity of Chinese chickens. This study provides a scientific basis for developing and applying FCHs as feed additives. However, more research is necessary to elucidate the mode of action, level of inclusion, and the benefits of including the FCH in chicken diets.