AUTHOR=Mohamed Taha M. , Sun Weizhong , Bumbie Gifty Z. , Elokil Abdelmotaleb A. , Mohammed Khaled Abuelezz Fouad , Zebin Rao , Hu Ping , Wu Liuting , Tang Zhiru 

TITLE=Feeding Bacillus subtilis ATCC19659 to Broiler Chickens Enhances Growth Performance and Immune Function by Modulating Intestinal Morphology and Cecum Microbiota

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.798350

DOI=10.3389/fmicb.2021.798350

ISSN=1664-302X

ABSTRACT=<p>This study investigated dietary supplementation with <italic>Bacillus subtilis</italic> (<italic>BS)</italic> ATCC19659 on growth performance, biochemical indices, intestinal morphology, and cecum microflora in broiler chicks. A total of 600 Arbor 1-day Acres broilers of either sex were allotted to 5 treatments: chicks were fed a corn- and soybean-based diet (CON); chicks were fed basal diet containing 500 mg ZnB/kg (ZnB); chicks were fed basal diet containing 1 × 10<sup>8</sup> CFU/g feed of BS-ATCC19659 (BS-1); chicks were fed basal diet containing 3 × 10<sup>8</sup> CFU/g feed of BS-ATCC19659 (BS-3); and chicks were fed basal diet containing 5 × 10<sup>8</sup> CFU/g feed of BS-ATCC19659 (BS-5). Each treatment comprised 6 replicates with 20 birds for each replicate pen. Chicks in the BS-5 and BS-3 groups had higher body weight at the 21<sup>st</sup> and 42<sup>nd</sup> days and average daily gain from 1 to 21 days than that in the CON group (<italic>p</italic> &lt; 0.05). Chicks in the BS-5 and ZnB groups had higher serum antioxidant activities and immunity response than those in the CON group (<italic>p</italic> &lt; 0.05). Compared with the CON group, the liver mRNA abundance of <italic>GHR</italic>, <italic>TGF-β</italic>, <italic>IGF-1</italic>, <italic>IFN-γ</italic>, <italic>SOD</italic>, <italic>CAT</italic>, and <italic>GPX</italic> of chicks in three <italic>BS</italic> groups and the ileum villus length (μm) of chicks in BS-3 and ZnB groups was increased (<italic>p</italic> &lt; 0.05). Compared with the CON group, the villus height-to-crypt depth ratio of the ileum of chicks in the BS-5 and BS-3 groups and the crypt depth and villus height-to-crypt depth ratio of the jejunum in the BS-5 and ZnB groups were increased (<italic>p</italic> &lt; 0.05). The abundance of the <italic>Cyanobacteria</italic> phyla in the cecum decreased in response to treatment with both <italic>BS</italic>-ATCC19659 and ZnB groups (<italic>p</italic> &lt; 0.05). Compared with the CON group, the cecum abundance of genera <italic>GCA-900066575</italic> (<italic>Lachnospiraceae</italic>), <italic>Anaerofustis</italic>, and <italic>Papillibacter</italic> (<italic>Firmicutes</italic> phylum) in three <italic>BS</italic> groups were increased (<italic>p</italic> &lt; 0.05); The abundance of genus <italic>Escherichia–Shigella</italic> reduced in the BS-3 group (<italic>p</italic> &lt; 0.05). Compared with the CON group, the cecum abundance of genus <italic>Clostridia_unclassified</italic> in ZnB and BS-5 groups was decreased (<italic>p</italic> &lt; 0.05) of broilers. Generally, <italic>Bacillus subtilis</italic> ATCC19659 as feed additive positively affected growth performance, immunity response, and cecal microflora of broilers.</p>