Weaned piglets are vulnerable to nutritional, physiological, and psychological stressors, leading to abrupt taxonomic and functional shifts in the intestinal microbiome. In this study, an integrated approach combination of 16S rDNA gene sequencing and the mass spectrometry-based metabolomics techniques was used to investigate the effects of weaning stress on intestinal microbial composition and its metabolic profiles of piglets. Three litters of suckling piglets with same parity were chosen. The samples of colonic contents were collected from each selected piglets (weaned day, 3 days after weaned) for microbial and metabolomics analysis. The results showed that Lachnospiraceae, Negativicutes, Selenomonadales, Campylobacterales and other 15 species increased after weaning, while Porphyromonadaceace, Alloprevotella, Barnesiella and Oscillibacter decreased. Based on the function profiles prediction and metabolomic analysis, five key metabolic pathways including Phenylalanine metabolism, Citrate cycle (TCA cycle), Glycolysis or Gluconeogenesis, Propanoate metabolism, Nicotinate and nicotinamide metabolism might be the relevant pathways involved in weaning stress-induced gut microbiota dysbiosis. Taken together, these results indicated that weaning stress not only changed microbial composition and function but altered the microbial metabolic profiles in the intestine, which might provide a new insight in alleviating weaning stress and facilitating disease prevention during the period of weaning in piglets.

This study was conducted to investigate the effect of exogenous fecal microbiota transplantation on gut bacterial community structure, gut barrier and growth performance in recipient piglets. Twelve litters of Duroc × Landrace × Yorkshire piglets of the same birth and parity were weighed and divided into two groups. One group (recipient piglets) was inoculated orally with fecal microbiota suspension of healthy adult Jinhua pigs daily from day 1 to day 11. The other (control) was given orally the same volume of sterile physiological saline at the same time. The experiment lasted 27 days. The results showed that the relative abundance of Firmicutes, Prevotellaceae, Lachnospiraceae, Ruminococcus, Prevotella, and Oscillospira in the colon of recipient piglets was increased. Proteobacteria, Fusobacteriaceae, Clostridiaceae, Pasteuriaceae, Alcaligenaceae, Bacteroidaceae, Veillonellaceae, Sutterella, Escherichia, and Bacteroides in the colon of recipient piglets were decreased. An average daily weight gain of recipient piglets was increased, and diarrhea incidence of the recipient was decreased during the trial. Intestinal morphology and tight junction barrier of recipient piglets were improved. The optical density of sIgA⁺ cells, the number of goblet cells and relative expressions of MUC2 in the intestinal mucosa of recipient piglets were enhanced. Protein expressions of β-defensin 2 and mRNA expressions of TLR2 and TLR4 in the intestinal mucosa of recipient piglets were also increased. These findings supported that the exogenous fecal microbiota had significant effects on animal’s growth performance, intestinal barrier function, and innate immune via modulating the composition of the gut microbiota.

A growing body of evidence highlights the properties of flavonoids in natural foods for disease prevention. Due to their antioxidative, anti-inflammatory, and anti-carcinogenic activities, flavonoids have been revealed to benefit skeletal muscle, liver, pancreas, adipocytes, and neural cells. In this review, we introduced the basic classification, natural sources, and biochemical properties of flavonoids, then summarize the experimental results and underlying molecular mechanisms concerning the effects of flavonoid consumption on obesity, cancers, and neurogenerative diseases that greatly threaten public health. Especially, the dosage and duration of flavonoids intervening in these diseases are discussed, which might guide healthy dietary habits for people of different physical status.

Faecal microbiota transplantation [FMT] has shown promise as a treatment for inflammatory bowel disease [IBD]. Using a piglet model, our previous study indicated that exogenous faecal microbiota can increase the expressions of tight junction proteins, mucin and antimicrobial peptide in the intestinal mucosa, suggesting a beneficial effect of FMT on gut barrier and gastrointestinal health. However, specific connections between FMT-induced microbial changes and modulation of the intestinal barrier remain to be fully illustrated. Here, we aimed to determine the potential role of metabolic function of gut microbiota in the beneficial effects of FMT. The influence of FMT on the maintenance of intestinal homeostasis was assessed by early-life gut microbiota intervention on newborn piglets and subsequent lipopolysaccharide [LPS] challenge. Analysis of the gut microbiome and metabolome was carried out by 16S rRNA gene sequencing and multiple mass spectrometry platforms. FMT modulated the diversity and composition of colonic microbiota and reduced the susceptibility to LPS-induced destruction of epithelial integrity and severe inflammatory response. Metabolomic analysis revealed functional changes of the gut metabolome along with a significant increase of the typical microbiota-derived tryptophan catabolite indole-3-acetic acid in the colonic lumen. In concordance with the metabolome data, metagenomics prediction analysis based on 16S rRNA gene sequencing also demonstrated that FMT modulated the metabolic functions of gut microbiota associated with indole alkaloid biosynthesis, cytochrome P450 and intestinal homeostasis, which coincided with up-regulation of cytokine interleukin-22 and enhanced activation of aryl hydrocarbon receptor in the recipient colon. Our data reveal a regulatory effect of FMT on tryptophan metabolism of gut microbiota in the recipient colon, which may play a potential role in maintenance of the intestinal barrier.

Weaning stress induces intestinal barrier dysfunction and immune dysregulation in mammals. Various interventions based on the modulation of intestinal microbiota have been proposed. Our study aims to explore the effects of co-cultures from Lactobacillus acidophilus and Bacillus subtilis (FAM^®) on intestinal mucosal barrier from the perspective of metabolic function of gut microbiota. A total of 180 piglets were allocated to three groups, i.e., a control group (C, basal diet), a FAM group (F, basal diet supplemented with 0.1% FAM), and an antibiotic group (A, basal diet supplemented with antibiotic mixtures). Here, we showed FAM supplementation significantly increased body weight and reduced diarrhea incidence, accompanied by attenuated mucosal damage, increased levels of tight junction proteins, serum diamine oxidase (DAO) and antimicrobial peptides. In addition, 16S rRNA sequencing and metabolomic analysis revealed an increase in relative abundance of Clostridiales, Ruminococcaceae, Firmicutes and Muribaculaceae and a significant increase in the total short-chain fatty acids (SCFAs) and butyric acid in FAM-treated piglets. FAM also increased CD4⁺ T cells and SIgA⁺ cells in intestinal mucosa and SIgA production in colon contents. Furthermore, FAM upregulated the expression of IL-22, short-chain fatty acid receptors GPR43 and GPR41, aryl hydrocarbon receptor (AhR), and hypoxia-inducible factor 1α (HIF-1α). FAM shows great application prospect in gut health and provides a reference for infant weaning.

This study investigated the effects of dietary essential oils (EOs) on intestinal microbial composition and metabolic profiles in weaned piglets. The piglets were fed the same basal diet supplemented with EOs (EO) or without EOs (Con) in the current study. The results showed that the body weight gain was significantly increased, while the diarrhea incidence was significantly reduced in the EO group. In addition, EOs could modify the intestinal microbial composition of weaned piglets. The relative abundances of some beneficial bacterial species such as Bacilli, Lactobacillales, Streptococcaceae, and Veillonellaceae were significantly increased in the EO group. Metabolomics analysis indicated that protein biosynthesis, amino acid metabolism, and lipid metabolism were enriched in the EO group. And correlation analysis demonstrated that some gut bacterial genera were highly correlated with altered gut microbiota-related metabolites. Taken together, this study indicated that dietary EOs not only altered microbial composition and function but modulated the microbial metabolic profiles in the colon, which might help us understand EOs’ beneficial effects on intestinal health of weaned piglets.