Birth weight and subsequent weight gain is of critical importance in the survival and performance of piglets on a commercial swine farm setting. Oropharyngeal microbiome could influence immunity, and feeding behavior thus impacting health and weight gain. We used 16S rRNA gene sequencing to profile the composition and predicted metabolic functionality of the oropharyngeal microbiota in 8 piglets (4 with a birthweight ≤ 1.0 kg and 4 with a birthweight ≥ 1.7 kg) at 11, 26, and 63 days of age. We found 9 genera that were significantly associated with average daily gain (ADG) at 11 days (false discovery rate, FDR < 0.05) and 26 days of age (FDR < 0.1), respectively. The microbial functional profile revealed several pathways associated with ADG (FDR < 0.05). Among these, pathways related to degradation of catechols showed a positive association with ADG at 11, 26, and 63 days of age, implying a potential to breakdown the host-derived catecholamines. We also noted that pathways related to the biodegradation of nucleosides and nucleotides increased with ADG during the pre-weaning phase, while those involved in their biosynthesis decreased. Our findings provide insights into the oropharyngeal microbial memberships and metabolic pathways that are involved in a piglet's weight gain. Thus, providing a basis for the development of strategies aimed at improving weight gain in pigs.

The objective of this study was to evaluate the effect of Lactobacillus amylovorus, L. plantarum, galacto-oligosaccharide (GOS) and their synbiotic formulations on pH, volatile fatty acids (VFA), malodor, and microbial ecological profiles through a 24-h in vitro fermentation model. Inclusion of GOS alone and in synbiotic combination with either probiotic resulted in consistently lower pH and higher total gas volumes at 12 and 24 h of incubation. Notably, concentrations of odorous compounds (hydrogen sulfide, H2S and methyl mercaptan, CH3SH) in the total gas produced were significantly lower in these GOS-containing treatments relative to the controls and probiotic-only-treated groups. However, although ammonia showed an initial relative reduction at 12 h, concentrations did not differ among treatments at 24 h. Further, the GOS-containing treatments had remarkably higher total and individual VFAs, including acetate, propionate, and butyrate, relative to controls and the probiotic-only treatments. Analysis of microbial composition and diversity showed clustering of GOS-containing treatments away from the controls and probiotic-only treatments at 12 and 24 h of incubation. Our study suggests that GOS supplementation (alone or in combination with L. amylovorus or L. plantarum probiotic strains) has the potential to increase VFA production in the swine gut while lowering emissions of malodorous compounds, except ammonia, in their manure.

Synbiotics are feed supplements with the potential to promote health and productivity in pigs partly, through modulation of the intestinal microbiome. Our study used shotgun sequencing and 16S rRNA gene sequencing techniques to characterize the effect of a synbiotic containing three Lactobacillus species and a fructo-oligosaccharide on the proximal colonic microbiome of 4- to 7-month-old Korean native black gilts. With shotgun sequencing we constructed unique metagenome-assembled genomes of gut microbiota in Native Black Pig for the first time, which we then used for downstream analysis. Results showed that synbiotic treatment did not alter microbial diversity and evenness within the proximal colons, but altered composition of some members of the Lactobacillaceae, Enterococcaceae and Streptococcaceae families. Functional analysis of the shotgun sequence data revealed 8 clusters of orthologous groups (COGs) that were differentially represented in the proximal colonic microbiomes of synbiotic-treated Jeju black pigs relative to controls. In conclusion, our results show that administering this synbiotic causes changes in the functional capacity of the proximal colonic microbiome of the Korean native black pig. This study improves our understanding of the potential impact of synbiotics on the colonic microbiome of Korean native black pigs.

In this study, we evaluated the modulatory effect of synbiotics (probiotics + prebiotics) on the oropharyngeal, proximal colonic, and vaginal microbiomes of Korean native pigs using 16S rRNA gene sequencing. We found increased abundances of an unclassified deltaproteobacterial genus in oropharyngeal communities of pigs supplemented with a Lactobacillus-based synbiotic. These pigs also had increased abundances of unclassified genera of Tremblayales and Lactobacillales in their proximal colons. In another group, pigs supplemented with a Bacillus-based synbiotic had increased Megasphaera and reduced Campylobacter within their oropharyngeal microbiota. In addition, their vaginal microbiota had increased Clostridium and Halalkalibacillus, as well as reduced Filifactor and Veillonella. We then explored changes in the predicted microbial functionality, associated with the synbiotics. Our analysis showed a reduction in the abundance of a fatty acid and lipid biosynthesis pathway among proximal colonic microbiomes of the Lactobacillus-fed pigs. In pigs supplemented with a Bacillus-based synbiotic, the analysis showed reduced pathway abundances for the biosynthesis of carbohydrates, as well as vitamins, cofactors, and carrier molecules within their oropharyngeal microbiomes. Meanwhile, their vaginal microbiomes had higher pathway abundances for aromatic compound degradation and secondary metabolite biosynthesis, but lower abundances for amino acid degradation. The results confirmed our hypothesis that dietary synbiotics modulate the microbiome, not only in the proximal colon, but also the oropharyngeal cavity and vaginal tract of these pigs.