This study multidimensionally investigates the comprehensive effects of Lactobacillus plantarum (LP)-fermented feed on growth performance, intestinal health, and metabolic regulation in Pacific abalone (Haliotis discus hannai). The results demonstrate that LP fermentation significantly alters feed’s physical properties and nutritional profile, softening texture, increasing viscosity, and emitting an acidic aroma. Notably, it enhanced contents of cis-9-palmitoleic acid, α-linolenic acid (ALA), and functional amino acids (GABA, L-histidine, and L-asparagine), indicating that fermentation optimized ω-3 fatty acid accumulation and amino acid profiles through the modulation of fatty acid metabolic pathways, thereby improving feed biofunctionality and stress-resistant potential. Further analyses revealed that fermented feed markedly improved intestinal morphology in abalone, promoting villus integrity and upregulating tight junction proteins (ZO-1, Claudin) to reinforce intestinal barrier function. Concurrently, it downregulated inflammatory cytokines (TNF-α, NF-κB, IL-16) while upregulating anti-inflammatory factors (TLR4) and antioxidant-related genes (NRF2/KEAP1 pathway), synergistically mitigating intestinal inflammation and enhancing antioxidant capacity. Sequencing and untargeted metabolomics unveiled that fermented feed substantially remodeled gut microbiota structure, increasing Firmicutes abundance while reducing Bacteroidetes, with the notable enrichment of beneficial genera such as Mycoplasma. Metabolite profiling highlighted the significant activation of lipid metabolism, tryptophan pathway, and coenzyme A biosynthesis. A Spearman correlation analysis identified microbiota–metabolite interactions (such as Halomonas’ association with isethionic acid) potentially driving growth performance via metabolic microenvironment regulation. In conclusion, LP-fermented feed enhances abalone growth, immune response, and aquaculture efficiency through multi-dimensional synergistic mechanisms (nutritional optimization, intestinal homeostasis regulation, microbiota–metabolome crosstalk), providing critical theoretical foundations for aquafeed development and probiotic applications in aquaculture.

Rougui Tea (RGT) is a typical Wuyi Rock Tea (WRT) that is favored by consumers for its rich taste and varied aroma. The aroma of RGT is greatly affected by the process of green-making, but its mechanism is not clear. Therefore, in this study, fresh leaves of RGT in spring were picked, and green-making (including shaking and spreading) and spreading (unshaken) were, respectively, applied after sun withering. Then, they were analyzed by GC-TOF-MS, which showed that the abundance of volatile compounds with flowery and fruity aromas, such as nerolidol, jasmine lactone, jasmone, indole, hexyl hexanoate, (E)-3-hexenyl butyrate and 1-hexyl acetate, in green-making leaves, was significantly higher than that in spreading leaves. Transcriptomic and proteomic studies showed that long-term mechanical injury and dehydration could activate the upregulated expression of genes related to the formation pathways of the aroma, but the regulation of protein expression was not completely consistent. Mechanical injury in the process of green-making was more conducive to the positive regulation of the allene oxide synthase (AOS) branch of the α-linolenic acid metabolism pathway, followed by the mevalonate (MVA) pathway of terpenoid backbone biosynthesis, thus promoting the synthesis of jasmonic acid derivatives and sesquiterpene products. Protein interaction analysis revealed that the key proteins of the synthesis pathway of jasmonic acid derivatives were acyl-CoA oxidase (ACX), enoyl-CoA hydratase (MFP2), OPC-8:0 CoA ligase 1 (OPCL1) and so on. This study provides a theoretical basis for the further explanation of the formation mechanism of the aroma substances in WRT during the manufacturing process.

The intensive development of livestock and poultry farming has heavily relied on antibiotics, leading to widespread antimicrobial resistance and posing serious threats to food safety and public health. As the industry transitions towards reduced antibiotic use and sustainable animal production, probiotics and their metabolites have garnered attention as functional alternatives. Probiotics are typically administered in the form of microecological preparations by mixing them into feed or water, offering advantages in cost-effectiveness and ease of use, with demonstrated efficacy in promoting animal health. Swine-derived probiotics, in particular, demonstrate host-specific advantages due to their natural adaptation to the porcine gastrointestinal environment, which improves intestinal colonization, pathogen inhibition, and immune modulation. Their metabolites, including short-chain fatty acids, bacteriocins, and exopolysaccharides, further contribute to these benefits through antimicrobial, anti-inflammatory, and barrier-strengthening effects. Recent studies have demonstrated improvements in average daily gain (18–22%) and feed conversion ratio (12–15%), along with a reduction in diarrhea incidence (up to 40–45%) in weaned piglets supplemented with certain probiotic consortia. It should be noted, however, that part of the supporting evidence is derived from in vitro or non-porcine models, and practical outcomes in swine may vary depending on husbandry conditions, probiotic strain, and husbandry conditions. This review systematically summarizes the isolation and identification of swine-derived probiotics, the active components and functions of their metabolites, and the mechanisms of action and application effects of these metabolites as antibiotic-alternative feed additives. It primarily focuses on innovative research advances in probiotic metabolites for enhancing antibacterial activity and improving pig growth performance. Furthermore, the review discusses the prospects for commercial applications and future research directions, aiming to provide theoretical foundations and technical references for green and healthy farming practices.

Significant regional variations in seawater characteristics (temperature, salinity, pH, nutrients) exist across marine environments, yet their impacts on abalone gastrointestinal microbiota and metabolites remain underexplored. This study investigated seawater nutrient and pH interactions on abalone gut ecosystems through comparative analysis of three marine regions (Pingtan (PT), Xiapu (XP), Lianjiang (LJ)). Seawater characteristics revealed distinct patterns: LJ exhibited the lowest total phosphorus (TP: 0.12 mg/L), total nitrogen (TN: 2.8 mg/L), NH₃-N (0.05 mg/L) but the highest salinity (32.1‰) and lowest pH (7.82), while PT/XP showed elevated nutrients (TP: 0.24–0.28 mg/L; TN: 4.2–4.5 mg/L). Microbial diversity peaked in LJ samples (Shannon index: 5.8) with dominant genera Psychrilyobacter (12.4%) and Bradyrhizobium (9.1%), contrasting with PT’s Mycoplasma-enriched communities (18.7%) and XP’s Vibrio-dominant profiles (14.3%). Metabolomic analysis identified 127 differential metabolites (VIP > 1.5, p < 0.05), predominantly lipids (38%) and organic acids (27%), with pathway enrichment in sulfur relay (q = 4.2 × 10⁻⁵) and tryptophan metabolism (q = 1.8 × 10⁻⁴). Stomach-specific metabolites correlated with fatty acid degradation (e.g., inosine diphosphate, r = −0.82 with vibrionimonas) and glutathione metabolism (methionine vs. mycoplasma, r = −0.79). Critically, pH showed negative correlations with beneficial Psychrilyobacter (oleamide: r = −0.68) and positive associations with pathogenic Vibrio (trigonelline: r = 0.72). Elevated NH₃-N (>0.15 mg/L) and TP (>0.25 mg/L) promoted Mycoplasma proliferation (R² = 0.89) alongside cytotoxic metabolite accumulation. These findings demonstrate that higher pH (>8.0) and nutrient overload disrupt microbial symbiosis, favoring pathogens over beneficial taxa.

The Intestinal system of nursery pigs is not fully matured and is easily disturbed by dietary composition and nutritional content. Probiotic-fermented feed has emerged as a beneficial dietary form for nursery pigs and is widely utilized in the livestock and poultry industries. However, there are limited reports regarding the effects of Lactobacillus plantarum-fermented feed on intestinal health and growth performance in nursery pigs. In this study, we investigated the effect of Lactobacillus plantarum NX69-fermented soybean by multi-omics approaches on intestinal health and growth performance in nursery pigs. The results demonstrated that NX69-fermented soybean meal increased small intestinal villus height, the villus height-to-crypt depth ratio (V/C), and the number of goblet cells per unit length. Additionally, it enhanced the mRNA of intestinal mucosal barrier factors ZO-1, Occludin, and Claudin in nursery pigs. Further research revealed that NX69-fermented soybean meal increased the diversity of the intestinal microbiota structure, elevated the abundance of core microbiota such as Alloprevotella, Prevotellaceae, and Megasphaera in the cecum, and increased the abundance of genera such as Megasphaera, Faecalibacterium, and Ruminococcus, which are known to produce short-chain fatty acids (SCFAs) in the cecum. Correlation analysis indicated that the core microbiota were positively correlated with intestinal physical barriers, including villus length and the V/C ratio, as well as with the mRNA level of intestinal mucosal barrier factors ZO-1, Occludin, and Claudin. Furthermore, they were positively correlated with differential metabolites such as Ginkgetin, Formiminoglutamic acid, Naringenin, and Hydroxyisocaproic acid. These findings suggest that NX69-fermented soybean meal can enhance the intestinal mucosal barrier in nursery pigs by increasing the abundance of core microbiota that produce SCFAs and then promoting intestinal health and improving growth performance, indicating promising application prospects.

Eurotium cristatum-Fermented White Tea (FWT) significantly alters white tea (WT) composition, increasing caffeine while decreasing polyphenols and amino acids. FWT effectively ameliorated dextran sulfate sodium (DSS)-induced murine colitis symptoms (reducing weight loss, colon shortening). Mechanistically, FWT suppressed TLR4/Myd88/NF-κB signaling and pro-inflammatory cytokines (TNF-α, IL-6, IL-1β) while upregulating tight junction proteins (ZO-1, occludin, claudin-1), MUC2, and E-cadherin. Single-cell/spatial transcriptomics revealed that FWT treatments augment enterocyte, goblet cell, and stem cell populations, optimize goblet function, restructure stem cell differentiation, and induce epithelial REG3B (antimicrobial) and LYPD8 (motility inhibitor), plus immunomodulator GM42418 lncRNA across cell types, repairing the barrier. FWT intervention was also associated with an increase in beneficial bacteria (Akkermansia, Lactobacillus, Bifidobacterium), restoration of microbiota balance, and elevated levels of short-chain fatty acids (SCFAs) and was associated with alterations in caffeine-related metabolite profiles. Collectively, these multi-scale changes correlate with the alleviation of UC, suggesting an integrated mechanism involving mucosal barrier repair, immune–stromal modulation, microbiota–metabolism regulation, and cellular reprogramming.