AUTHOR=Liu Yang , Lin Qian , Huang Xuan , Jiang Guitao , Li Chuang , Zhang Xu , Liu Shengli , He Lingyun , Liu Yali , Dai Qiuzhong , Huang Xingguo 

TITLE=Effects of Dietary Ferulic Acid on the Intestinal Microbiota and the Associated Changes on the Growth Performance, Serum Cytokine Profile, and Intestinal Morphology in Ducks

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.698213

DOI=10.3389/fmicb.2021.698213

ISSN=1664-302X

ABSTRACT=<p>The present study investigated the effects of ferulic acid (FA) on the growth performance, serum cytokine profile, intestinal morphology, and intestinal microbiota in ducks at the growing stage. 300 female <italic>Linwu</italic> ducks at 28 days of age with similar body weights were randomly divided into five groups. Each group contained six replicates of 10 birds. The dietary treatments were corn-soybean-based diet supplemented with FA at the concentrations of 0 (control), 100, 200, 400, and 800 mg/kg diet. The results demonstrated that dietary FA at the levels of 200, 400, and 800 mg/kg increased the average daily gain (<italic>P</italic> = 0.01), 400 and 800 mg/kg FA increased the final body weight (<italic>P</italic> = 0.02), 100, 200, and 800 mg/kg FA increased the serum glutathione (<italic>P</italic> = 0.01), and 100, 400, and 800 mg/kg FA increased the glutathione peroxidase activities in birds (<italic>P</italic> &lt; 0.01). Additionally, 200, 400, and 800 mg/kg dietary FA lowered the serum levels of interleukin-2 (<italic>P</italic> = 0.02) and interleukin-6 (<italic>P</italic> = 0.04). Moreover, the morphometric study of the intestines indicated that 400 mg/kg FA decreased the crypt depth in jejunum (<italic>P</italic> = 0.01) and caecum (<italic>P</italic> = 0.04), and increased the ratio of villus height to crypt depth in jejunum (<italic>P</italic> = 0.02). Significant linear and/or quadratic relationships were found between FA concentration and the measured parameters. 16S rRNA sequencing revealed that dietary FA increased the populations of genera <italic>Faecalibacterium</italic>, <italic>Paludicola</italic>, RF39, and <italic>Faecalicoccus</italic> in the cecum (<italic>P</italic> &lt; 0.05), whereas decreased the populations of <italic>Anaerofilum</italic> and UCG-002 (<italic>P</italic> &lt; 0.05). The Spearman correlation analysis indicated that phylum <italic>Proteobacteria</italic> were negatively, but order <italic>Oscillospirales</italic>, and family <italic>Ruminococcaceae</italic> were positively related to the parameters of the growth performance. Phylum <italic>Bacteroidetes</italic>, class <italic>Negativicutes</italic> and family <italic>Rikenellaceae</italic> were negatively associated with the parameters of the antioxidative capability. And phylum <italic>Cyanobacteria</italic>, <italic>Elusimicrobia</italic>, and <italic>Bacteroidetes</italic>, class <italic>Bacilli</italic>, family <italic>Rikenellaceae</italic>, and genus <italic>Prevotella</italic> were positively associated with the parameters of the immunological capability. Thus, it was concluded that the supplementations of 400 mg/kg FA in diet was able to improve the growth performance, antioxidative and immunological capabilities, intestinal morphology, and modulated the gut microbial construction of <italic>Linwu</italic> ducks at the growing stage.</p>