Currently, knowledge about the impact of long-term intake of high resistant starch diet on pig hindgut microbiota and metabolite profile is limited. In this study, a combination of the pyrosequencing and the mass spectrometry (MS)-based metabolomics techniques were used to investigate the effects of a raw potato starch (RPS, high in resistant starch) diet on microbial composition and microbial metabolites in the hindgut of pig. The results showed that Coprococcus, Ruminococcus, and Turicibacter increased significantly, while Sarcina and Clostridium decreased in relative abundances in the hindgut of pigs fed RPS. The metabolimic analysis revealed that RPS significantly affected starch and sucrose metabolites, amino acid turnover or protein biosynthesis, lipid metabolites, glycolysis, the pentose phosphate pathway, inositol phosphate metabolism, and nucleotide metabolism. Furthermore, a Pearson’s correlation analysis showed that Ruminococcus and Coprococcus were positively correlated with glucose-6-phosphate, maltose, arachidonic acid, 9, 12-octadecadienoic acid, oleic acid, phosphate, but negatively correlated with α-aminobutyric acid. However, the correlation of Clostridium and Sarcina with these compounds was in the opposite direction. The results suggest that RPS not only alters the composition of the gut microbial community but also modulates the metabolic pathway of microbial metabolism, which may further affect the hindgut health of the host.

Gut microbiota is generally recognized to play a crucial role in maintaining host health and metabolism. The correlation among gut microbiota, glycolipid metabolism, and metabolic diseases has been well reviewed in humans. However, the interplay between gut microbiota and host metabolism in swine remains incompletely understood. Given the limitation in conducting human experiments and the high similarity between swine and humans in terms of anatomy, physiology, polyphagy, habits, and metabolism and in terms of the composition of gut microbiota, there is a pressing need to summarize the knowledge gained regarding swine gut microbiota, its interplay with host metabolism, and the underlying mechanisms. This review aimed to outline the bidirectional regulation between gut microbiota and nutrient metabolism in swine and to emphasize the action mechanisms underlying the complex microbiome–host crosstalk via the gut microbiota–gut–brain axis. Moreover, it highlights the new advances in knowledge of the diurnal rhythmicity of gut microbiota. A better understanding of these aspects can not only shed light on healthy and efficient pork production but also promote our knowledge on the associations between gut microbiota and the microbiome–host crosstalk mechanism. More importantly, knowledge on microbiota, host health and metabolism facilitates the development of a precise intervention therapy targeting the gut microbiota.

Butyrate in the gut of animals has potential properties including regulating the innate immune, modulating the lipid metabolism, and protecting gut healthy. So far, only limited information on the impact of butyrate on the neonatal is available. This study aimed to investigate effects of oral administration of sodium butyrate (SB) on gut microbiota and the expression of inflammatory cytokine in neonatal piglets. Ten litters of crossbred newborn piglets were randomly allocated to the SB and control (CO) groups, each group consisted of five litters (replicates). Piglets in the SB group were orally administrated with 7 to 13 ml sodium butyrate solution (150 mmol/l) per day from the age of 1 to 7 days, respectively; piglets in the CO group were treated with the same dose of physiological saline. On days 8 and 21 (of age), gut digesta and tissues were collected for the analysis of microbiota, butyrate concentration and gene expression of inflammatory cytokine. Results showed that there was no difference in the butyrate concentration in the gut of piglets on days 8 and 21 between two groups. Real-time PCR assay showed that SB had no effect on the numbers of total bacteria in the stomach, ileum, and colon. MiSeq sequencing of the V3-V4 region of the 16S rRNA gene revealed that SB increased the richness in the stomach and colon, and the diversity of colonic microbiota on day 8 (P < 0.05). Genera Acinetobacter, Actinobacillus, Facklamia, Globicatella, Kocuria, Rothia, unclassified Leptotrichiaceae, unclassified Neisseriaceae, and unclassified Prevotellaceae in the stomach were increased in relative abundance by SB treatment, whereas the abundances of Lactobacillus decreased on day 8 (P < 0.05). At the genus and operational taxonomic unit (OTU) levels, SB had low impact on bacterial community in the ileum and colon on days 8 and 21. SB treatment decreased the expression of IL-6, IL-8, IFN-γ, IL-10, TGF-β, and histone deacetylase 1 (HDAC1) in the ileum of piglets on day 8 (P < 0.05). SB treatment down-regulated the expression of IL-8, IFN-γ, and IL-1β on day 21 (P < 0.05). Correlation analysis on the combined datasets revealed some potential relationships between gut microbiota and the expression of inflammatory cytokines. The results show that early intervention with sodium butyrate can modulate the ileum inflammatory cytokine in neonatal piglets with low impact on intestinal microbial structure, which suggests oral administration of SB may have a benefit role in the health of neonatal piglets.

Intake of raw potato starch (RPS) has been associated with various intestinal health benefits, but knowledge of its mechanism in a long-term is limited. The aim of this study was to investigate the effects of long-term intake of RPS on microbial composition, genes expression profiles in the colon of pigs. Thirty-six Duroc × Landrace × Large White growing barrows were randomly allocated to corn starch (CS) and RPS groups with a randomized block design. Each group consisted of six replicates (pens), with three pigs per pen. Pigs in the CS group were offered a corn/soybean-based diet, while pigs in the RPS group were put on a diet in which 230 g/kg (growing period) or 280 g/kg (finishing period) purified corn starch was replaced with purified RPS during a 100-day trial. Real-time PCR assay showed that RPS significantly decreased the number of total bacteria in the colonic digesta. MiSeq sequencing of the V3-V4 region of the 16S rRNA genes showed that RPS significantly decreased the relative abundance of Clostridium, Treponema, Oscillospira, Phascolarctobacterium, RC9 gut group, and S24-7-related operational taxonomic units (OTUs), and increased the relative abundance of Turicibacter, Blautia, Ruminococcus, Coprococcus, Marvinbryantia, and Ruminococcus bromii-related OTUs in colonic digesta and mucosa. Analysis of the colonic transcriptome profiles revealed that the RPS diet changed the colonic expression profile of the host genes mainly involved in immune response pathways. RPS significantly increased proinflammartory cytokine IL-1β gene expression and suppressed genes involved in lysosome. Our findings suggest that long-term intake of high resistant starch (RS) diet may result in both positive and negative roles in gut health.