Probiotics can promote the health and growth performance of animals through modulation
of intestinal microbiota. When used as a feed additive, they have the potential to
minimize or abolish the use of antibiotics. In this study, we investigated the effect
of the probiotic strain Bacillus amyloliquefaciens TL on the growth performance and
cecum microflora composition in Cobb 500 broiler chickens. In total, 180 broilers
were randomly divided into three groups-each group comprised 4 pens, and each pen
contained 15 chickens. The three groups were fed either a control diet, or a diet
supplemented with either the antibiotic chlortetracycline or B. amyloliquefaciens
TL. Broilers were weighed, and cecum contents were collected on days 7, 14, 21, and
35, respectively. The broilers in both the antibiotic and probiotic groups exhibited
significant weight gain compared with controls, exhibiting increases of 16.02% and
13.40%, respectively, after 35 days (P<0.01). Similarly, the feed conversion ratio
(FCR, 1-35 days) of broilers in the chlortetracycline and B. amyloliquefaciens TL
groups was lower than that of the controls. HiSeq high-throughput sequencing of 16S
rRNA of the cecal microbiota was performed on days 7, 14, 21, and 35, respectively.
The Firmicutes/Bacteroidetes ratio was higher in the chlortetracycline and B. amyloliquefaciens
TL groups than in the control group on days 14, 21, and 35, and especially on day
21. The prevalence of genera Oscillospira, Ruminococcus, Butyricicoccus, and Faecalibacterium
(Firmicutes) was higher in the antibiotic and probiotic groups, while that of Bacteroides,
Parabacteroides (Bacteroidetes), and Lactobacillus was higher in the control group.
In this study, the changes in the microbiota of the probiotic group were similar to
those in the antibiotic group. These results suggest that the probiotic strain B.
amyloliquefaciens TL can modulate the cecal microbiota of broilers similar to chlortetracycline.