AUTHOR=Pan Xue , Cai Yuanli , Kong Linglian , Xiao Chuanpi , Zhu Qidong , Song Zhigang 

TITLE=Probiotic Effects of Bacillus licheniformis DSM5749 on Growth Performance and Intestinal Microecological Balance of Laying Hens

JOURNAL=Frontiers in Nutrition

VOLUME=9

YEAR=2022

URL=https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2022.868093

DOI=10.3389/fnut.2022.868093

ISSN=2296-861X

ABSTRACT=<p>This study was conducted to investigate the effects of <italic>Bacillus licheniformis</italic> DSM5749 on the production performance and intestinal health in laying hens. A total of 32-week-old laying hens (Hyline Brown) were randomly assigned to two dietary groups (10 replicates of 27 laying hens), namely, basal diet and basal diet complemented with 200 g/t <italic>B. licheniformis</italic> (3.2 × 10<sup>9</sup> CFU/kg). The trial lasted for 8 weeks, and samples were collected at the last week. Results revealed that <italic>B. licheniformis</italic> DSM5749 significantly improved laying performance, including an increase in egg production rate and average daily egg yield, and a decrease in the feed-to-egg ratio during the entire 8-week experimental period (<italic>P</italic> &lt; 0.05). <italic>B. licheniformis</italic> DSM5749 increased the levels of superoxide dismutase and glutathione peroxidase in the liver and decreased the IL-1 level in the serum (<italic>P</italic> &lt; 0.05). In addition, the integrity of intestinal morphology (villus height, crypt depth, and villus height/crypt depth), tight junctions (<italic>ZO-1</italic>, <italic>Claudin-1</italic>, and Occludin), and lipase vitality in the intestine were potentiated by <italic>B. licheniformis</italic> DSM5749 in laying hens (<italic>P</italic> &lt; 0.05). <italic>B. licheniformis</italic> DSM5749 decreased the Firmicutes/Bacteroidetes ratio (<italic>P</italic> &lt; 0.05) in the cecum. Furthermore, <italic>B. licheniformis</italic> DSM5749 modulated the microbiota in the cecum of the laying hens, increased the relative abundance of beneficial bacteria (e.g., <italic>Prevotella</italic>) at the genus level and decreased the relative abundance of potential pathogens (e.g., <italic>Desulfovibrio</italic>). In conclusion, <italic>B. licheniformis</italic> DSM5749 can improve laying performance, promote intestinal health, affect the composition of cecal microorganisms, and regulate the intestinal micro-ecological balance, making <italic>B. licheniformis</italic> a good probiotic candidate for application in the laying hens industry.</p>