Probiotic Effects of Bacillus subtilis on Growth Performance and Intestinal Microecological Balance of Growing-to-Finishing Pigs

Abstract

The present study investigated the growth performance, immune status, gut morphology, and gut microflora modulation in growing-to-finishing pigs (n = 72; 24 pigs/group) after dietary supplementation with Bacillus subtilis (B. subtilis; two groups (experiment 1 (E1) and experiment 2 (E2): 63 and 98 days, respectively) and control (Ct, basal diet). The results revealed that both 1–98 d and 1–63 d groups significantly improved growth performance, including an increase in midtest body weight (MBW) P = 0.0114 , final body weight (FBW) P < 0.0001 , and average daily gain (ADG) P < 0.0001 and a decrease in the ratio of feed to gain (F/G) P < 0.0001 . There was an increase in serum IgG and SOD levels after supplementation with B. subtilis P = 0.0074 . Furthermore, B. subtilis potentiated the integrity of intestinal morphology (villus height (VH) P < 0.0001 and villus height/crypt depth (VH/CD) P = 0.0009 ) in growing-to-finishing pigs. The LEfSe analysis identified 11 and 13 biomarkers in the fecal samples of the 1–63 d group and 1–98 d, respectively. The gut microflora alterations of growth-finishing pigs suggested that dietary B. subtilis could promote gut health by altering the relative abundances of different bacterial communities. A correlation analysis showed that B. subtilis could regulate the functional network of the intestine microflora and their interactions with its host. Taken together, dietary B. subtilis supplementation had a positive influence on the growth performance, gut health, and the composition of gut microorganisms, suggesting that B. subtilis can be used as a functional probiotic candidate for application in the production of growing-to-finishing pigs. Practical Applications. The addition of probiotics in the diet can modulate intestinal health, improve the digestibility of nutrients, and thus, help improve the nutrient utilization and production performance of pigs. It is one of the ideal substitutes for antibiotics. This study will help us understand the function of B. subtilis in the regulation of pig intestinal health, so as to provide scientific basis for the rational use of probiotics in the future pig industry.

The Effects of Microbial Additive Supplementation on Growth Performance, Blood Metabolites, Fecal Microflora, and Carcass Characteristics of Growing–Finishing Pigs

“…Therefore, an immune change can shift the energy utilized in excessive immune stimulation toward growth and improve feed efficiency. Furthermore, our results are well supported by those of a previous study in which growing-to-finishing pigs that received supplementation with B. subtilis had a positive impact on the evident increase in the effect of the probiotic on IgG [43]. However, there were no differences in serum IgA and immunoglobulin M levels between the groups.…”

Characterization of the Effects of a Novel Probiotic on Salmonella Colonization of a Piglet-Derived Intestinal Microbiota Using Improved Bioreactor

“…For the alpha diversity, the continuous treatments lowered richness more than the daily dose condition even after the product was removed from the bioreactor ( Table 4 ). The Bacillus -based product used in our study seemed to be more potent in the diminution of the alpha diversity compared to other studies, especially for the continuous mode of administration [ 40 , 41 ]. This finding could be explained by the duration of the experiment, which was short, the compounds present in the Bacillus -based product, which could bear a strong antimicrobial activity, or the possible synergy between the probiotic secreted antimicrobial compounds or enzymes that increased the microbiota modulation.…”

“…After 24 h of treatment, the continuous treatment samples differentiated more from the control when compared to the daily dose treatment, and this remained true over time ( Figure 2 ). Some studies showed no significant change in beta diversity in the gut microbiota when administrating a Bacillus -based probiotic to swine [ 41 , 43 ], but others did [ 40 , 44 ]. This might be due to the length that the treatments were administered, the mode of administration, or a difference in the product tested.…”