AUTHOR=Zhu Cui , Gong Li , Huang Kaiyong , Li Fangjun , Tong Diqing , Zhang Huihua 

TITLE=Effect of Heat-Inactivated Compound Probiotics on Growth Performance, Plasma Biochemical Indices, and Cecal Microbiome in Yellow-Feathered Broilers

JOURNAL=Frontiers in Microbiology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.585623

DOI=10.3389/fmicb.2020.585623

ISSN=1664-302X

ABSTRACT=<p>This study was carried out to investigate the effect of heat-inactivated compound probiotics on growth performance, plasma biochemical indices, and gut microbiota composition and functions in yellow-feathered broilers. A total of 360 1-day-old broilers were randomly divided into 3 groups, including a basal diet as negative control group (PC), basal diet plus antibiotics with 250 mg/kg calcium oxytetracycline and 200 mg/kg Nosiheptide as positive control (PC), and basal diet plus 500 mg/kg compound probiotics consisting of heat-inactivated <italic>Bacillus subtilis</italic> and <italic>Lactobacillus acidophilus</italic> BFI (BFI). Each group had 6 replicates of 20 chickens. On d 21, 42, and 63, one chick from each replicate was selected for blood collection and cecal sampling. Compared to the NC group, dietary supplementation with heat-inactivated compound probiotics increased the feed efficiency during d 1–63 (<italic>P</italic> &lt; 0.05). The plasma cholesterol content at 42 d and creatinine content at 63 d were decreased by dietary supplementation with heat-inactivated compound probiotics (<italic>P</italic> &lt; 0.05). The dominant phyla in broiler cecal microbiota were <italic>Bacteroidetes, Firmicutes</italic>, and <italic>Proteobacteria</italic>, while the dominant genera were <italic>Bacteroides, Ruminococcaceae</italic>, and <italic>Phascolarctobacterium</italic>. The β-diversity index of cecal microbiota in BFI group was increased at d 42 (<italic>P</italic> &lt; 0.01) and d 63 (<italic>P</italic> &lt; 0.05). Dietary heat-inactivated compound probiotics increased the relative abundances of <italic>Barnesiellaceae</italic> (family), <italic>Barnesiella</italic> (genus), and <italic>Lactobacillus aviarius</italic> (species) at d 21, and reduced the relative abundances of genera <italic>Lachnoclostridium</italic> and <italic>Peptococcus</italic> at d 42, and unidentified <italic>Lachnospiraceae</italic> and <italic>Lachnoclostridium</italic> at d 63. The functional prediction of microbiota revealed that supplementation with heat-inactivated compound probiotics enriched the pathways related to methane metabolism, transcription machinery, purine metabolism and protein export. The Spearman's correlation analysis identified a significant correlation between cecal microbiota composition and overall feed efficiency and plasma metabolites. Collectively, dietary heat-inactivated compound probiotics with <italic>Bacillus subtilis</italic> and <italic>Lactobacillus acidophilus</italic> BFI enhanced feed efficiency, and decreased plasma cholesterol and creatinine contents, which might be associated with the modulation of community composition, diversity and functions of cecal microbiota in yellow-feathered broilers. These results indicated the potential of heat-inactivated probiotics used as alternatives to antibiotics for improvement of broiler health and productivity.</p>