Xia Xiong

Polysaccharides are well known for their immunomodulatory properties and gut microbiota-regulating functions; however, their digestive stability and structure-dependent biological mechanisms remain poorly understood. This study investigated the in vitro enzymatic resistance and intestinal regulatory effects of a novel L-β-galactoglucan (Mw 400–520 kDa) derived from Agrobacterium sp. FN01, and further evaluated the in vivo effects of its corresponding crude fermentation product on growth performance and intestinal metabolism in pigs. Twenty-seven-day-old weaned piglets were randomly allocated to three treatments, with 16 pens per treatment and 13 piglets per pen, and fed basal diets supplemented with 0, 200, or 400 mg/kg of the crude product. The results showed that L-β-galactoglucan exhibited strong resistance to pancreatic α-amylase and glucoamylase under the tested in vitro conditions, with minimal release of low-molecular-weight oligosaccharides during hydrolysis. The 400 mg/kg crude product supplementation significantly improved growth performance, reduced the feed-to-gain ratio, and increased the apparent total tract digestibility of dry matter, crude protein, crude fat, and gross energy (p < 0.05). In addition, dietary supplementation with this crude product increased intestinal microbial diversity, enriched Halalkalibacter urbisdiaboli, and increased colonic concentrations of isobutyrate and isovalerate (p < 0.05). Functional metagenomic analysis further revealed enhanced microbial carbohydrate metabolism and energy metabolic pathways. In conclusion, under the in vitro conditions tested in this study, the novel L-β-galactoglucan exhibited resistance to the two tested enzymes. In the pig trial, this polysaccharide improved growth performance and nutrient utilization, and modulated the intestinal microbial composition. These observations suggest that the fermentation product may be promising for animal feeding applications.

Eucommia ulmoides leaf extract (ELE) boasts a high concentration of bioactive components including flavonoids, chlorogenic acid, and polysaccharides. It exhibits multiple biological functions, including antioxidant, anti-inflammatory, and gut microbiota-modulating properties, showing great potential in enhancing immunity, maintaining intestinal health, and delaying cellular senescence. This study investigated the protective effects and underlying mechanisms of ELE against D-galactose-induced senescence in chick embryo primary intestinal epithelial cells (IECs). Using an in vitro model (200 mmol/L D-galactose), we found that 100 µg/mL ELE pretreatment significantly preserved cell viability, mitigated apoptosis, and delayed cellular senescence, as evidenced by cytological and biochemical assays. Furthermore, RNA-seq transcriptomic analysis identified seven key differentially expressed genes (DEGs) mediating these anti-aging effects. Mechanistic investigations revealed that ELE modulates ATP6V0D2 and NCF2 to activate autophagy signaling pathways. This ELE-induced promotion of autophagy effectively suppresses inflammatory responses in IECs, thereby delaying senescence progression. These findings elucidate the molecular mechanisms by which ELE antagonizes intestinal cellular senescence, providing a solid theoretical foundation for its development as a functional anti-aging additive in the food industry.

Introduction: Impaired intestinal immune function is commonly observed in neonates with intrauterine growth retardation (IUGR), yet its underlying mechanisms and regulatory pathways remain poorly understood. Therefore, we aimed to investigate gene regulatory patterns and microbiota alterations in IUGR piglets. Methods: Three newborn IUGR piglets and three normal littermates were selected from the same sow and sacrificed at seven days of age. Ileal digesta was collected for 16S rRNA amplicon sequencing (16S-seq), and ileum segments were dissociated for single-cell RNA sequencing (scRNA-seq). Results: The scRNA-seq results revealed a reduced proportion of plasma B cells in IUGR piglets, along with alterations in the distribution of various T cell subsets. KEGG pathway analysis further indicated a downregulation of the B cell receptor signaling pathway in B cells from IUGR piglets. In contrast, both the T cell receptor signaling pathway and antigen processing and presentation were attenuated in T cells. Pseudotime trajectory analysis suggested that the differentiation of B cells was impaired in IUGR piglets. SCENIC analysis revealed that GATA3, IRF2, and BCL11A were downregulated in T cells of IUGR piglets. The 16S-seq results revealed that α-diversity was lower in IUGR piglets. At the genus level, the relative abundance of Prevotella was significantly lower in IUGR piglets. Discussion: Significant changes were identified in the proportions of B and T cells, their associated signaling pathways, and intestinal microbiota composition in IUGR piglets, suggesting underlying immune dysfunction and dysbiosis. Conclusion: We identified novel immune-related transcription factors and key microbes as potential therapeutic targets, shedding light on strategies for preventing and treating IUGR.

Chlorogenic acid from Eucommia ulmoides leaves is a promising natural antioxidant for food applications, yet its extraction and purification require optimization to improve yield and purity. This study employed ultrasound-assisted ethanol extraction on fresh leaves, evaluating the effects of ethanol concentration, solid-to-liquid ratio, extraction time, and temperature on CGA yield. Optimal extraction parameters were determined using response surface methodology. Purification with NKA-II macroporous resin increased CGA purity to 82.72%. SEM analysis revealed wrinkled and porous surface structures, while FTIR confirmed the presence of characteristic hydroxyl, carbonyl, and aromatic groups. Under optimized conditions (70% ethanol, solid-to-liquid ratio 1:20 g/mL, 58 °C, 61 min), the extraction yield reached 6.96%. In vitro assays demonstrated strong antioxidant activity, with scavenging rates of 96.01% for DPPH, 89.69% for hydroxyl, and 99.82% for ABTS radicals at 5 mg/mL. These findings provide an efficient method for obtaining chlorogenic acid from Eucommia ulmoides leaves and support its potential as a functional food ingredient.

Milk sources directly influence digestion, absorption, and overall nutrient utilization during early infant nutrition. Goat milk features a nutritional composition and digestive properties that are more similar to human breast milk. This study aimed to investigate the effects of different milk sources on the immunity, amino acid and fatty acid metabolism, and intestinal microbiota in neonatal piglets. Sixteen 7-day-old suckling piglets were randomly allocated into two groups (eight replicates/group, one piglet/replicate) and fed with standard formula milk powder (CON) and goat milk formula powder (GMF). The formal experiment lasted for 14 days. Results showed that compared with the CON group, the GMF group showed a significant increase (p < 0.05) in the final weight, the serum levels of immunoglobulin A (IgA), IgG, IgM and C-reactive protein (CRP4), and intestinal trypsin content. Additionally, the GMF group had higher (p < 0.05) serum essential and non-essential amino acid and fatty acid levels, and had trends toward upregulation (0.05 < p < 0.1) in hepatic mRNA expression of spermine N1-acetyltransferase 1 (SAT1), duodenal peptide transporter 1 (PePT1), and jejunal cationic amino acid transporter 1 (CAT1). Microbiome sequencing revealed that GMF enhanced intestinal microbial richness and diversity and increased concentrations of acetic and propionic acids (p < 0.05). In conclusion, GMF suggests a potential improvement in the growth performance by enhancing immunity, amino acid and fatty acid metabolism and optimizing intestinal microbiota composition in neonatal piglets. These findings further support the favorable nutritional properties and tolerability of GMF in early-life nutrition.

Glutamine (Gln) supplementation during the weaning period can alleviate stress in piglets. However, free Gln has poor stability and low absorption in the small intestine. Glycyl-glutamine (Gly-Gln), a stable dipeptide form of Gln, has been evaluated as a potential alternative in pig nutrition. This study investigated the effects of Gly-Gln at 0, 0.125%, 0.25%, 0.375%, and 0.50%, as well as a Gly + Gln positive control, on growth performance, intestinal morphology, immunity, antioxidant status, and nutrient apparent digestibility in weaned piglets. The results showed that dietary supplementation with 0.25%, 0.375%, or 0.50% Gly-Gln significantly increased average daily gain, average daily feed intake, and final weight (p < 0.05). Linear and quadratic effects (p < 0.05) were observed for growth performance indicators, suggesting that moderate supplementation levels yielded optimal benefits. Dietary Gly-Gln supplementation with 0.25%, 0.375%, or 0.50% Gly-Gln significantly increased serum immunoglobulin (IgG, IgA, and IgM), insulin, insulin growth factor 1, growth hormone, and T4 and T3 contents, and decreased IFN-γ and IL-1β contents (p < 0.05). Diets supplemented with 0.25, 0.375, or 0.50% Gly-Gln increased total antioxidant capacity and superoxide dismutase content in serum and liver, and decreased MDA content (p < 0.05). Compared with the negative control group, dietary supplementation of 0.25%, 0.375%, or 0.50% Gly-Gln significantly increased the mRNA expression of ZO-1, Occludin, and Claudin-1 in the jejunum (p < 0.05). Furthermore, crude protein digestibility was significantly improved in piglets receiving 0.375% and 0.5% Gly-Gln (p < 0.05), with a significant linear relationship between Gly-Gln level and digestibility. In conclusion, 0.25% is the minimum effective dose of Gly-Gln for improving weaning outcomes. Gly-Gln is more effective than equivalent doses of free glycine and glutamine in enhancing growth performance, gut barrier integrity, and nutrient utilization in weaned piglets.

The intestine is the largest immune and barrier organ in the body, and diarrhea and even death during piglet development are related to dysfunction caused by intestinal barrier damage and inflammation. A water-soluble β-glucan produced by Agrobacterium ZX09 has been shown to have a beneficial effect on gastrointestinal health. The main objective of this study was to investigate whether pre-feeding β-glucan has a protective effect on LPS-induced immune stress in piglets. In this study, 24 weaned piglets (21-day-old; 6.64 ± 0.16 kg) were assigned to 4 treatments in a two × two factorial design with diet (with or without β-glucan) and immunological challenge (saline or LPS). Piglets were challenged with saline or LPS after 39 days of feeding 0 or 200 mg/kg β-glucan. The results demonstrated that β-glucan supplementation increased the average daily weight gain and daily feed intake, and decreased diarrhea rate of piglets. Intestinal inflammation symptoms and histological changes in LPS-challenged piglets were alleviated by pre-feeding of β-glucan. β-glucan supplementation reduced serum IL-1β (interleukin-1β) and NO (nitric oxide) secretion in piglets after LPS challenge (0.01 < p < 0.05). Supplementation with β-glucan downregulated the mRNA expression of IL-6 in piglets after LPS challenge (0.01 < p < 0.05). β-glucan supplementation enriched the short-chain fatty acid-producing bacteria, such as Agathobacter and Subdoligranulum (0.01 < p < 0.05), and increased the concentrations of propionate and butyrate (0.01 < p < 0.05). In conclusion, pre-feeding β-glucan can enhance piglet immunity and promote piglet growth by influencing gut microbiota composition and metabolism, and alleviate intestinal damage after LPS challenge.

Breast milk (BM) is the optimal nutrition source for infants, providing highly digestible proteins. In contrast, the digestibility of proteins in infant formula (IF) varies, influenced by differences in proteins such as α-lactalbumin (α-La) and β-casein (β-CN). This study aimed to evaluate the true ileal digestibility (TID) of amino acids (AAs) in BM and IF with varying α-La and β-CN contents using neonatal piglets. Twenty-four 11-day-old piglets (4 groups; 6 replicates/group) received either a nitrogen-free diet, IF (high infant formula (HIF) with 1.74 g/100 α-La and 2.3 g/100 β-CN; low infant formula (LIF) with 1.07 g/100 α-La and 1.85 g/100 β-CN), or BM (1.82 g/100 α-La and 3.05 g/100 β-CN) for 7 days after 3 prefeed days. IF had higher concentrations of nitrogen, serine, threonine, and proline than BM. Glutamic acid was the most abundant AA in IF and BM, while methionine in BM and LIF or tryptophan in HIF was the least. BM showed the highest TID of AAs, with the LIF had the lowest. The HIF group's TID for AAs, especially tryptophan, was similar to BM and significantly better than LIF. These results suggest that adjusting the α-La and β-CN ratio in IF can improve AA digestibility, approaching BM levels.

This study investigated the effect of peroxidized lipids on piglets’ growth performance, intestinal morphology, inflammatory reactions, oxidative stress in the liver, duodenum, jejunum, ileum, and colon, and ileal microbiota. Twenty piglets (Duroc × [Landrace × Yorkshire]; age = 21 d old, BW = 6.5 ± 1 kg) were randomly assigned to two groups with 10 replicates per group and one piglet per replicate. The control group was fed 6% fresh soybean oil and the peroxidized soybean oil (PSO) group fed 6% PSO. The experimental feeding period lasted 24 d. The study found no impact on ADFI, ADG and gain to feed ratio (P > 0.05). However, the PSO group increased the diarrhea index and the serum levels of lactate dehydrogenase triglycerides, cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol (P < 0.05), along with decreased concentrations of alanine aminotransferase and blood urea nitrogen (P < 0.05). For oxidative enzymes, PSO increased the concentration of F2-isoprostane in urine (P = 0.032), malondialdehyde (MDA) in the duodenum (P = 0.001) and jejunum (P = 0.004), decreased thiobarbituric acid reactive substances (TBARS) in the liver (P = 0.001) but increased TBARS in duodenum (P = 0.001), and carbonylated proteins in the duodenum (P = 0.003). For antioxidant enzymes, PSO decreased superoxide dismutase (SOD) in the liver (P = 0.001), colon (P = 0.002), and jejunum (P = 0.015), along with glutathione peroxidase (GSH-Px) in the liver (P = 0.008) and NAD(P)H:quinone oxidoreductase 1 (NQO1) in ileum (P = 0.001). For inflammatory reactions, PSO increased interleukin (IL)-1β concentrations in the duodenum and colon, and IL-10 in the jejunum, while decreasing IL-4 concentration in the duodenum (P < 0.05). For intestinal morphology and ileal microbiota, PSO increased ileal crypt depth, while decreasing the crypt-to-villus ratio (P < 0.05). Peroxidized soybean oil increased the relative abundance of Prevotella, Clostridium_sensu_stricto_1, Clostridium_sensu_stricto_6, Pasteurella and Klebsiella (P < 0.05). In conclusion, this study revealed that PSO worsened diarrhea, increasing the ileal crypt depth and the relative abundance of harmful microbiota, and induced oxidative stress and inflammation in the intestines and liver, primarily in the jejunum and ileum.

Artemisia annua residue (AR), as the byproduct of industrial extraction of artemisinin, contains rich nutrients and active ingredients. This study was conducted to determine the effects of AR as an unconventional feed material on growth performance, immunity, and intestinal health in weaned piglets. Thirty-two piglets weaned at 21 days (7.53 ± 0.31 kg average BW) were fed with a corn–soybean basal diet (BD) and a basal diet with 1% (LAR), 2% (MAR), and 4% (HAR) AR diets for 28 days. AR diets increased the serum IgA and complement component 3 levels, superoxide dismutase activity, and villus height in the duodenum (p < 0.05). The MAR group increased the ADG, serum total protein, and mRNA expression levels of Claudin-1 in the duodenum and zonula occludens-1 (ZO-1) and the mucin 2 (MUC2) in the colon, as well as colonic Romboutsia and Anaerostipes abundances, and decreased the Proteobacteria abundance (p < 0.05). To sum up, dietary AR supplementation may enhance growth performance by improving serum immunoglobulin and antioxidant enzyme activity, intestinal morphology, tight junction protein expression, and gut microbiota of weaned piglets. Regression analysis showed that the optimal AR supplemental level for growth performance, immunity, antioxidant ability, and intestinal health of weaned piglets was 2.08% to 4.24%.