Effects of Bacillus subtilis on growth performance, serum parameters, digestive enzyme, intestinal morphology, and colonic microbiota in piglets

Bo Deng,Cheng Zhang,Ziwei Xu,Xiaoming Men,Jie Wu,Xiaohui Li

doi:10.1186/s13568-020-01150-z

Abstract

The present study was conducted to investigate effects of Bacillus subtilis on growth performance, serum parameters, digestive enzymes, intestinal morphology, and colonic microbiota in piglets. A total of 72 piglets were weighed and randomly allotted into three treatments (four replication pens per treatment with six piglets/pen) for a 28-day experiment. The dietary treatments were as follows: basal diet (control group, CTR), basal diet supplementation with antibiotic (antibiotic group, ABT), and basal diet supplementation with 0.1% Bacillus subtilis (probiotic group, PBT). The average daily gain of body weight increased in both the ABT and PBT groups, and dietary antibiotics decreased the feed:gain ratio (F:G), as compared to the CTR group (P < 0.05). Both ABT and PBT piglets had increased serum triglycerides and lipase, amylase, maltase activities and villus height:crypt depth ratio (V/C) in ileum (P < 0.05). The PBT group also showed an increase in serum glucose and villus height in the ileum (P < 0.05). Dietary antibiotics increased Lactobacillus johnsonii, as compared to the CTR group, but decreased bacterial diversity and increased Escherichia coli, as compared to the PBT group (P < 0.05). Piglets dietary with B. subtilis modulated the microbiota by increasing the abundance of Firmicutes (L. johnsonii, L. reuteri) and decreasing the abundance of E. coli, as compared to the control group (P < 0.05). These results indicate that dietary of B. subtilis improves growth performance and intestinal health and can be a promising alternative to antibiotics in piglets diet.

Highlights

Environmental and nutritional stressors affect health and growth performance in all life phases of livestock production
The three treatments were: basal diet, basal diet supplied with 40 mg/kg kitasamycin and 75 mg/kg chlorotetracycline, and basal diet supplied with 0.1% B. subtilis
Piglets supplemented with B. subtilis showed positive effects in growth performance, with increased final body weight (BW) and average daily gain (ADG), as compared to the Control group (CTR) group (P < 0.05)

Summary

Introduction

Environmental and nutritional stressors affect health and growth performance in all life phases of livestock production. Numerous studies have demonstrated the beneficial effects of B. subtilis without safety concerns (Guo et al 2006; Lee et al 2014; Zhou et al 2015). While not all strains are resistant to the environment in the gastrointestinal tract, and the pharmabiotic action of probiotics (including Bacillus spp.) from different strains is multi-factorial and strain-specific, some strains are more beneficial to the host than others (Weichselbaum 2009). We had demonstrated a strain of B. subtilis which improved intestinal function, reduced inflammation and developed microflora in LPSinduced acute inflammation rat (Deng et al 2017). We further evaluated the effect of B. subtilis on growth performance, serum parameters, digestive enzymes, intestinal morphology, and colonic microbiota in piglets

Methods

Results

Conclusion