Effect of Bacillus subtilis and Bacillus licheniformis supplementation in diets with low- and high-protein content on ileal crude protein and amino acid digestibility and intestinal microbiota composition of growing pigs

Abstract

Background Bacillus spp. seem to be an alternative to antimicrobial growth promoters for improving animals’ health and performance. However, there is little information on the effect of Bacillus spp. in combination with different dietary crude protein (CP) levels on the ileal digestibility and microbiota composition. Therefore, the objective of this study was to determine the effect of Bacillus spp. supplementation to low- (LP) and high-protein diets (HP) on ileal CP and amino acid (AA) digestibility and intestinal microbiota composition.MethodsEight ileally cannulated pigs with an initial body weight of 28.5 kg were randomly allocated to a row-column design with 8 pigs and 3 periods of 16 d each. The assay diets were based on wheat-barley-soybean meal with two protein levels: LP (14% CP, as-fed) and HP diet (18% CP, as-fed). The LP and HP diets were supplemented with or without Bacillus spp. at a level of 0.04% (as-fed). The apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of CP and AA was determined. Bacterial community composition from ileal digesta was analyzed by Illumina amplicon sequencing and quantitative real-time PCR. Data were analyzed as a 2 × 2 factorial design using the GLIMMIX procedures of SAS.ResultsThe supplementation with Bacillus spp. did not affect both AID and SID of CP and AA in growing pigs. Moreover, there was no difference in AID of CP and AA between HP and LP diets, but SID of cystine, glutamic acid, glycine, and proline was lower (P < 0.05) in pigs fed the HP diets. The HP diets increased abundance of Bifidobacterium spp. and Lactobacillus spp., (P < 0.05) and by amplicon sequencing the latter was identified as predominant genus in microbiota from HP with Bacillus spp., whereas dietary supplementation of Bacillus spp. increased (P < 0.05) abundance of Roseburia spp..ConclusionsThe HP diet increased abundance of Lactobacillus spp. and Bifidobacterium spp.. The supplementation of Bacillus spp. resulted in a higher abundance of healthy gut associated bacteria without affecting ileal CP and AA digestibility, whereas LP diet may reduce the flow of undigested protein to the large intestine of pigs.

Bacillus licheniformis-Fermented Products Reduce Diarrhea Incidence and Alter the Fecal Microbiota Community in Weaning Piglets

“…In our study, we demonstrated that supplementation of antibiotics in the diet also had a negative effect on the richness and diversity of the fecal microbiota of piglets. It has been reported that the richness and evenness of the microbiota were decreased in the feces of pigs fed Bacillus species-based probiotics [16,26]. Similarly, 1 g/kg of B. licheniformis-fermented products also reduce the richness and evenness of the fecal microbiota in piglets in the present study.…”

“…Interestingly, no obvious negative effects on bacterial richness and evenness were observed in the fecal content of the group that was fed 4.5 g/kg of B. licheniformis-fermented products. The abundance of Lactobacillus species and Bifidobacterium species were increased in the feces of growing pigs fed Bacillus species-based probiotics [26]. A linear trend of Bacillus species-based probiotics supplementation on the number of Lactobacillus species was found [21].…”

Multiple-Omics analysis revealed the high fiber diets promote the gluconeogenesis and inhibit the glycolysis process in muscle

“…The rumen microbiota has some special microbial species to help ruminants to degrade feeds. In this paper, the genus Prevotella showed a decrease in the high fiber diet, which is not consistent with the previous study in human and pigs [31]. Prevotella is largely responsible for much of the proteolytic activity within the rumen and is important for breaking down plant protein into usable nitrogen, which becomes accessible for other microbes within the rumen [32].…”

Varying ensiling conditions affect the fermentation quality and abundance of bacterial key players in lucerne silages

“…For absolute quantification of the 16S rRNA gene copy numbers, internal standards were created using a pool sample (Kaewtapee et al, 2017). Standards were purified using the GeneJET PCR Purification Kit (Thermo Scientific, Schwerte, Germany) and fluorometrically quantified using the Synergy .…”