Pingting Guo

3-Nitropropionic acid (3-NPA) is an irreversible inhibitor of succinate dehydrogenase (SDH; mitochondrial complex II) that is widely used to model mitochondrial metabolic stress. Direct reproductive studies now show that 3-NPA can increase ovarian oxidative stress, granulosa-cell apoptosis, follicular atresia, alter ovarian reserve, impair oocyte maturation, and reduce fertility in experimental models. However, no ovarian study has yet demonstrated the complete succinate–HIF-1α–NLRP3 cascade proposed here. We therefore propose a testable framework in which SDH inhibition causes succinate accumulation and impaired respiratory electron flux, while redox stress provides an additional signal for HIF-1α stabilization and NLRP3 activation. Succinate-mediated inhibition of prolyl hydroxylases provides a mechanistic route to HIF-1α stabilization under normoxic or near-normoxic conditions, whereas NLRP3 activation may integrate mitochondrial danger signals with inflammatory signaling. Importantly, HIF-1α is not intrinsically pathogenic in the ovary: physiological HIF-1α signaling supports angiogenesis, ovulation, granulosa-cell survival, autophagy, and luteal remodeling, whereas persistent or excessive activation may become maladaptive. We further refine the proposed metabolic–inflammatory threshold as a measurable state in which combined succinate/redox burden and inflammasome activation exceed the adaptive capacity of a follicular unit. The model predicts that time-resolved measurements of succinate, SDH activity, HIF-1α stabilization, NLRP3 activation, and follicular outcomes should reveal ordered relationships that can be tested by pharmacological and genetic intervention. This review distinguishes direct ovarian evidence from cross-system mechanistic evidence and identifies the experiments required to establish causality.

Follicular development is a complex and dynamic biological process involving coordinated interactions among endocrine regulation, cellular metabolism, redox homeostasis, mitochondrial function, and immune signaling. Increasing evidence indicates that oxidative stress, metabolic remodeling, and inflammatory responses are closely interconnected within the ovarian microenvironment and collectively influence follicular developmental outcomes. The NLRP3 inflammasome, traditionally recognized as an intracellular sensor of danger-associated signals, has recently emerged as an important mediator linking oxidative stress, mitochondrial dysfunction, metabolic disturbances, and inflammatory activation. Within ovarian tissues, NLRP3 activation has been associated with granulosa cell function, inflammatory remodeling, follicular atresia, ovulatory processes, and reproductive disorders. In this review, we summarize current knowledge regarding the regulation and functional implications of NLRP3 signaling during follicular development, with particular emphasis on its interactions with redox metabolism, mitochondrial homeostasis, and inflammatory pathways. Based on currently available evidence, we propose a hypothesis-driven framework in which NLRP3 may act as a candidate redox-metabolic integrative node that coordinates stress-related signals within the follicular microenvironment and may contribute to developmental transitions including follicular growth, dominance acquisition, ovulatory competence, and atresia. Importantly, this framework does not suggest that NLRP3 independently determines follicular fate. Rather, it provides a conceptual model describing how NLRP3-associated inflammatory signaling may interact with endocrine, metabolic, and redox networks to influence follicular developmental trajectories. The proposed framework remains to be validated through cell-specific genetic models, temporal intervention studies, and quantitative molecular profiling approaches. Understanding the potential integrative role of NLRP3 may provide new insights into the mechanisms underlying ovarian disorders, including polycystic ovary syndrome, primary ovarian insufficiency, and ovarian aging, while highlighting potential directions for future therapeutic exploration.

Fatty acid amide hydrolase (FAAH) is a critical metabolic enzyme in the endocannabinoid system. Through regulating the metabolism of lipid signaling molecules, FAAH is involved in a variety of physiological and pathological processes, including cell proliferation, inflammatory responses, and metabolic homeostasis. Polycystic ovary syndrome (PCOS), one of the most common endocrine and metabolic disorders affecting women of reproductive age, is closely associated with abnormal follicular development, dysregulated hormone secretion, insulin resistance, dyslipidemia, and inflammatory imbalance. Emerging evidence suggests that FAAH-mediated dysregulation of endocannabinoid metabolism is associated with the pathogenesis of PCOS through the modulation of inflammatory pathways, insulin sensitivity, and hormone secretion. This review systematically summarizes the structure, biological functions, and regulatory mechanisms of FAAH, with particular emphasis on its roles in PCOS-associated pathological processes, including reproductive dysfunction, hormonal dysregulation, metabolic imbalance, and inflammatory responses. This review aims to provide a theoretical foundation for elucidating the molecular mechanisms underlying PCOS and for the development of novel therapeutic strategies.

This study comparatively analyzed the spatial heterogeneity of the gut microbiome across gastrointestinal segments in Changle geese versus yellow-feathered broilers to discover their links with growth and intestinal development. Twelve 63-day-old male yellow-feathered broilers and twelve 70-day-old male Changle geese were selected. Body weight (BW), slaughter weight (SW), absolute lengths of the small intestine (LSI) and cecum (LC), and their relative lengths normalized to body size (RLSI/RLC) were measured. Additionally, 16S rDNA sequencing of crop, proventriculus, gizzard, jejunum, cecum, and rectum microbiota was conducted to assess microbial diversity, composition, and its correlation with phenotypes. Results demonstrated higher BW, SW, LSI, LC and lower RLSI and RLC in geese versus broilers (p < 0.001). Alpha diversity analysis revealed lower microbial richness and diversity in broilers across most gastrointestinal segments (p < 0.05), while beta diversity analysis confirmed distinct community structures between two species (p = 0.001). Firmicutes dominated broiler gut microbiota (94.49%), whereas geese exhibited greater phylum-level diversity (p < 0.05). Random forestry analysis identified Top 15 core Amplicon Sequencing Variants in both the cecum and rectum, with ASV12260 (unclassified Lachnospiraceae) and ASV12412 (uncultured Faecalibacterium sp.) as key biomarkers. Correlation analyses found 21 phenotype-related ASVs (p < 0.05). Specially, two Lactobacillus ingluviei strains showed negatively correlated with LSI and RLSI in the chicken foregut (p < 0.05). And two Gallibacterium anatis strains were associated with RLSI, with one strain also showing an inverse correlation with LSI in the goose foregut (p < 0.05). Interestingly, one Peptococcus strain was negatively correlated with BW and SW, while the other was inversely associated with LC and RLC in the goose hindgut (p < 0.05). These findings provide insights into species-specific distribution patterns of gut microbiota across poultry species and their correlation with growth performance and intestinal development, developing a theoretical foundation for advancing avian digestive physiology research and optimizing feeding strategies.

This study was conducted to evaluate the impacts of brewer’s grains (BG) on growth performance, apparent nutrient digestibility, immunity, antioxidant capacity, and fecal microbiota of Simmental crossbred cattle and the economic benefits. A completely randomized design was adopted in our study. Twenty-four 15-month-old finishing Simmental crossbred male cattle (body weight, 433.43 ± 32.47 kg) were randomly assigned to three groups: control group (basal diet), 10% BG group (supplemented with 10% BG on a dry matter basis), and 15% BG group (supplemented with 15% BG on a dry matter basis). The trial lasted for 48 days, with serum samples collected on days 24 and 48 and fecal samples collected from days 46 to 48. Diets did not influence the average daily gain, dry matter intake, feed efficiency, and serum antioxidant parameters (p > 0.05). The 15% BG group showed significantly higher acid detergent fiber digestibility (p < 0.01) and elevated serum albumin levels on day 48 (p = 0.047) compared with the control group. As for fecal microbiota, there was a lower Chao index (p = 0.040) and a higher abundance of Romboutsia in the 15% BG group (p = 0.025). Moreover, the feed costs of cattle fell by 9.34% and 14.66% after 10% and 15% BG supplementation, respectively. On the whole, BG supplementation demonstrated no significant effects on growth performance or animal health in finishing cattle. The 15% inclusion level demonstrated the greatest cost reduction potential. We, therefore, recommend adopting 15% BG supplementation as the optimal strategy to enhance economic returns in cattle production systems.

This study evaluated the synergistic effects of essential oils (EOs), Saccharomyces cerevisiae (SC), and isomaltooligosaccharides (IMO) on intestinal health and systemic immunity in weaned piglets using a randomized block design across two commercial farms. Within each farm, 108 piglets weaned at 24 d of age were randomly divided into 3 groups (3 pens per group, 12 piglets per pen). The piglets were fed a basal diet (CON) and a basal diet supplemented with antibiotics (0.5 kg/t colistin sulfate + 0.5 kg/t tilmicosin) (ANTI) or additive mixture (0.1 kg/t EOs, 0.3 kg/t SC and 1 kg/t IMO) (ESI) for 28 days. The results showed that both ESI and ANTI treatments significantly increased the ratio of villus height to crypt depth (P < 0.05). Specifically, ESI supplementation elevated serum IgA, hepatic IgA, and jejunal mucosal sIgA levels (P < 0.05), while upregulating hepatic IL1B, IL2, IL6, and IFNG expression alongside jejunal mucosal IL1B, IL6, and PPARG expression—contrasting with its downregulation of jejunal mucosal IFNG mRNA (P < 0.05). Conversely, compared with the CON group, ANTI supplementation increased serum IgA level and jejunal mucosal concentrations of sIgA, IgG, IgM, IFN-γ, and IL-10, while also upregulating jejunal mucosal gene expression of IGF1 and TGFB1 (P < 0.05). In addition, compared with Farm I, piglets at Farm II exhibited higher jejunal pH, elevated serum levels of IgA and IL-1β, and upregulated gene expression of IL1B, IL2, IL6, and IFNG in the liver as well as TGFB1, IL1B, IL6, and PPARG in the jejunal mucosa (P < 0.05). Moreover, the robust diet × farm interaction effects on immune gene expression in the liver (IL1B, IL2, and IL6) and jejunal mucosa (IL1B, IL2, IL6, IFNG, IL10, and PPARG) were observed (P < 0.05). Collectively, ESI improved jejunal epithelial maturation, nutrient absorption, and immune function in weaned piglets, with efficacy partly dependent on farm environmental conditions.

The present study was undertaken to evaluate the impacts of nano-composites of copper and carbon (NCCC) on the intestinal luminal micro-ecosystem and mucosal homeostasis of yellow-feather broilers. A total of two-hundred and forty 1-day-old male yellow-feather broilers were randomly allocated into four groups, each with five replications of twelve birds. The control (CON) group received a corn-soybean basal diet, while the N50, N100, and N200 groups were supplemented with 50, 100, and 200 mg/kg of NCCC in basal diets, respectively. The trial duration was 63 days. The findings demonstrated that there were slight impacts of NCCC addition on the intestinal luminal micro-ecosystem of broilers, with the fecal moisture content in the N100 group being slightly higher on Day 3 in the starter phase (p < 0.05). The cecal microbiota structure also did not obviously change (p > 0.05), in spite of the fall in the relative abundance of the Ruminococcus torques group in the N50 group and norank Clostridia UCG-014 in N200 group (p < 0.05). But for intestinal mucosal homeostasis, NCCC played a crucial part in jejunal morphology, tight junction, immunologic status, and antioxidant capacity. There was linear growth in villus height and a quadratic increase in villus height, crypt depth and their ratio with the increase in NCCC dosage (p < 0.05), and 100 mg/kg NCCC supplementation could intensify the expression of CLDN-3 genes (p < 0.05). In addition, IL-4 and IL-10 linearly increased after NCCC treatment (p < 0.05), along with some irregular changes in sIgA (p < 0.05). In addition, higher jejunal mucosal total antioxidant capacities in N50 and N200 groups were also observed (p < 0.05). Overall, NCCC treatment optimized the intestinal mucosa function of broilers in terms of physical barrier and immune and antioxidant capacities, but exerted subtle influence in the luminal environment of yellow-feather broilers. More precisely, dietary supplementation with 50 mg/kg NCCC is recommended for intestinal homeostasis of broilers.

The purpose of this experiment was to investigate the effects of Hot Water Extract of Juncao-substrate Ganoderma lucidum Residue (HWE-JGLR) on the immune function and intestinal health of yellow-feather broilers. In an animal feeding experiment, 288 male yellow-feather broilers (1 day old) were randomly allocated to four treatment groups with six replicates of 12 birds each. The control (CON) group was fed a basal diet. HJ-1, HJ-2, and HJ-3 were fed a basal diet supplemented with 0.25%, 0.50%, and 1.00% HWE-JGLR, respectively. The feeding trial lasted for 63 d. The results showed increased ADFI (p = 0.033) and ADG (p = 0.045) of broilers in HJ-3, compared with the CON group. Moreover, higher contents of serum IL-4 and IL-10 and gene expression of IL-4 and IL-10 in jejunum mucosa and lower contents of serum IL-1β and gene expression of IL-1β in jejunum mucosa in HJ-3 were observed (p < 0.05). Additionally, the jejunal mucosal gene expression of Claudin-1 and ZO-1 in HJ-2 and HJ-3 was higher than that in the CON group (p < 0.05). As for the microbial community, compared with the CON group, the ACE index, Shannon index, and Shannoneven index of cecal microorganisms in HJ-2 and HJ-3 were elevated (p < 0.05). PCoA analysis showed that the cecal microbial structure of broilers in HJ-2 and HJ-3 was different from the CON group (p < 0.05). In contrast with the CON group, the broilers in HJ-2 and HJ-3 possessed more abundant Desulfobacterota at the phylum level and unclassified Lachnospiraceae, norank Clostridia vadinBB60 group and Blautia spp. at the genus level, while Turicibacter spp. and Romboutsia spp. were less (p < 0.05). In conclusion, dietary supplementation with HWE-JGLR can improve growth performance, enhance body immunity and intestinal development, and maintain the cecum microflora balance of yellow-feather broilers.

A healthy animal intestine hosts a diverse population of bacteria in a symbiotic relationship. These bacteria utilize nutrients in the host’s intestinal environment for growth and reproduction. In return, they assist the host in digesting and metabolizing nutrients, fortifying the intestinal barrier, defending against potential pathogens, and maintaining gut health. Bacterial colonization is a crucial aspect of this interaction between bacteria and the intestine and involves the attachment of bacteria to intestinal mucus or epithelial cells through nonspecific or specific interactions. This process primarily relies on adhesins. The binding of bacterial adhesins to host receptors is a prerequisite for the long-term colonization of bacteria and serves as the foundation for the pathogenicity of pathogenic bacteria. Intervening in the adhesion and colonization of bacteria in animal intestines may offer an effective approach to treating gastrointestinal diseases and preventing pathogenic infections. Therefore, this paper reviews the situation and mechanisms of bacterial colonization, the colonization characteristics of various bacteria, and the factors influencing bacterial colonization. The aim of this study was to serve as a reference for further research on bacteria–gut interactions and improving animal gut health.

The aim of this study was to investigate the effects of mixed organic acids (MOAs) on growth performance, immunity, antioxidants, intestinal digestion, and barrier function in Ira rabbits. A total of 192 weaned male Ira rabbits at 35 days of age were randomly assigned to four groups with six replicates of eight rabbits each. The rabbits in the control group (CON) were fed a basal diet, and the antibiotic group (SAL) was fed a basal diet supplemented with 60 mg/kg salinomycin. The test groups were fed a basal diet supplemented with 1000 mg/kg and 2000 mg/kg MOAs (MOA1 and MOA2, respectively). The experiment lasted for 55 days. The results showed that the ADG of Ira rabbits in the SAL group and MOA1 group was higher than that in the CON group (p < 0.05). The serum IL-6 and liver MDA levels of Ira rabbits in the SAL group, MOA1 group, and MOA2 group were lower than those in the CON group (p < 0.05). In addition, sIgA levels in the jejunal mucosa of Ira rabbits in the SAL group and MOA1 group were increased compared with those in the CON group (p < 0.05). Compared with the CON group, the gene expression of IL-6 was decreased (p < 0.05) in the jejunal mucosa of Ira rabbits in the SAL, MOA1, and MOA2 groups, while the gene expression of IL-1β tended to decrease (p = 0.077) and the IL-10 content tended to increase (p = 0.062). Moreover, the gene expression of ZO-1 in the jejunal mucosa of Ira rabbits was elevated in the MOA1 group compared with the CON group (p < 0.05). In conclusion, dietary supplementation with MOAs can improve growth performance, enhance immune function and antioxidant capacity, and maintain the intestinal barrier in weaned Ira rabbits.