Cecal Contents Research Articles

515 Effects of Bacillus licheniformis HG76 on barrier function and inflammation in the intestinal epithelia cells and gut health of weaned piglets under enterotoxigenic Escherichia coli F4 infection

Abstract Enterotoxigenic Escherichia coli (ETEC) F4 secretes enterotoxins and invades the small intestine, which damages the gut barrier function and stimulates the immune reactions characterized by inflammation. In the current study, the effects of B. licheniformis HG76 on gut health were evaluated with ETEC F4-induced IPEC-J2 cells and weaned piglets. The B. licheniformis HG76 was isolated from cecal contents of Rhode Island Red laying hens raised without using antibiotics. The results from the in vitro study showed that the ETEC F4 infection significantly induced IPEC-J2 cell death, and this effect was significantly attenuated by B. licheniformis HG76 treatment (P < 0.05). The gene expressions of zona occludens (ZO1) and tumor necrosis factor (TNF)-α were significantly increased during ETEC F4 infection with B. licheniformis HG76 treatment (P < 0.05). Meanwhile, the ETEC F4 infection significantly increased the mRNA abundance of toll-like receptors (TLR2, TLR4, and TLR5) (P < 0.05), but the B. licheniformis HG76 treatment alleviated this increase. For the in vivo study, 28 weaned piglets susceptible to ETEC F4 at 28 d of age were individually allotted to four experimental groups: NNC: unchallenged control group; NC: challenged control group; PC: antibiotic group (80 mg·kg-1 of avilamycin); and HG76: Bacillus group (1.0 × 109 CFU kg-1 diet of B. licheniformis HG76). The in vivo results showed during the post-challenge phase, ETEC F4 infection decreased average daily gain (ADG) and increased the severity of diarrhea at 44 h post-inoculum (hpi), respectively, in the NC group compared with the NNC group (P < 0.05). In addition, the infection decreased the villus height (VH) in the duodenum of pigs from the NC, PC and HG76 groups compared with the NNC group. The VH of jejunum and ileum in the pigs from the HG76 group were higher than other groups (P < 0.05). There was an increase (P < 0.05) of crypt depth (CD) in the jejunum and ileum of pigs from the HG76 group compared with those from the NNC group. The pigs in the NNC group had the greatest duodenal VH:CD ratio, but the least ileal VH:CD ratio among all the treatment groups. The Vmax value of sucrase in the HG76 group was greater than the NNC group (P < 0.05). When compared with the NC group, the relative mRNA abundance of interleukin 6 (IL6) was increased in the PC group (P < 0.05). In summary, these results suggest that B. licheniformis HG76 can protect the intestinal cells from ETEC F4 infection by inhibiting inflammation and maintaining barrier integrity, and the supplementation of B. licheniformis HG76 can improve the gut development and increase the digestive enzyme activity of ETEC F4 challenged piglets.

Combined analysis of cecal microbiota and metabolomics reveals the intervention mechanism of Dayuan Yin in acute lung injury.

The ancient Chinese medicinal formula, Dayuan Yin (DYY), has a long history of use in treating respiratory ailments and is shown to be effective in treating acute infectious diseases. This study aims to explore how DYY may impact intestinal flora and metabolites induced by acute lung injury (ALI). ALI rats were induced with lipopolysaccharide (LPS) to serve as models for assessing the anti-ALI efficacy of DYY through multiple lung injury indices. Changes in intestinal microflora were assessed via 16SrRNA gene sequencing, while cecum contents were analyzed using non-targeted metabonomics. Differential metabolites were identified through data analysis, and correlations between metabolites, microbiota, and inflammatory markers were examined using Pearson's correlation analysis. DYY demonstrated a significant improvement in LPS-induced lung injury and altered the composition of intestinal microorganisms, and especially reduced the potential harmful bacteria and enriched the beneficial bacteria. At the gate level, DYY exhibited a significant impact on the abundance of Bacteroidota and Firmicutes in ALI rats, as well as on the regulation of genera such as Ruminococcus, Lactobacillus, and Romboutsia. Additionally, cecal metabonomics analysis revealed that DYY effectively modulated the abnormal expression of 12 key metabolic biomarkers in ALI rats, thereby promoting intestinal homeostasis through pathways such as purine metabolism. Furthermore, Pearson's analysis indicated a strong correlation between the dysregulation of intestinal microbiota, differential metabolites, and inflammation. These findings preliminarily confirm that ALI is closely related to cecal microbial and metabolic disorders, and DYY can play a protective role by regulating this imbalance, which provides a new understanding of the multi-system linkage mechanism of DYY improving ALI.

Mitigation effects of plant carbon black on intestinal morphology, inflammation, antioxidant status, and microbiota in piglets challenged with deoxynivalenol.

Plant carbon black (PCB) is a new feed additive for zearalenone adsorption in China. However, information regarding whether PCB can effectively absorb deoxynivalenol (DON) is limited. To explore this research gap, the present study examined the adsorption effectiveness of DON by PCB using a phosphate buffer, artificial gastric juice, and artificial intestinal juice. In a 21-day in vivo trial, 48 male piglets were randomly assigned to four treatment groups: (1) uncontaminated basal diet (CTR), (2) basal diet supplemented with 1 mg/kg PCB(PCB), (3) 2.3 mg/kg DON-contaminated diet (DON), and (4) 2.3 mg/kg DON-contaminated diet supplemented with 0.1% PCB (DON+PCB). When DON concentration was 1 µg/mL, the adsorption rate of PCB on DON in phosphate buffer systems (pH 2.0 and 6.0) and the artificial gastric and intestinal juices were 100%, 100%, 71.46%, and 77.20%, respectively. In the in vivo trial, the DON group significantly increased the DON+deepoxy-deoxynivalenol (DOM-1) content in serum as well as the inflammation cytokine proteins (interleukin-6, interleukin-8, and tumor necrosis factor-α) and mRNA expression of interleukin-6 and longchain acyl-CoA synthetase 4 in the jejunum and ileum. It decreased the villus height, goblet cells, mucosal thickness, and mRNA expression of Claudin-1 compared to the CTR group. In addition, DON decreased the Shannon and Simpson indices; reduced the relative abundances of Firmicutes, Lactobacillus, Candidatus_Saccharimonas, and Ruminococcus; and increased the relative abundances of Terrisporobacter and Clostridium_sensu_stricto_1 in the cecal content. In conclusion, these results suggest that PCB showed high adsorption efficacy on DON in vitro, and exhibit the protective effects against various intestinal toxicity manifestations in DON-challenged piglets.

Multi-omics analysis reveals associations between host gene expression, gut microbiota, and metabolites in chickens.

Egg-laying is an important trait in chickens, and it is affected by many factors, such as hormones regulated by the hypothalamic-pituitary axis and precursors synthesized by the liver. Recent studies showed that gut microbiota was associated with egg-laying, however, its underlying mechanism remains unclear. We comprehensively analyzed the host transcriptome, gut microbiota, and metabolome in broiler breeder hens during the pre-laying, peak-laying, and late-laying periods. The transcriptome analysis of the tissues related to the hypothalamic-pituitary-liver (HPL) axis revealed dynamic gene expression during egg-laying periods. Differentially expressed genes (DEGs) (i.e., PENK, NPY, AVP, PRL, RLN3, and FST) from the hypothalamus and pituitary gland were involved in female gonadal development, hormone secretion, response to endogenous stimulus, liver development, and amide metabolism. In liver, DEGs (i.e., FABP3, VTG1, LPL, APOA5, APOV1, and RBP5) were enriched in efferocytosis, sphingolipid metabolism, amide, and peptide biosynthesis. Alpha and beta diversity changed significantly in cecum microbiota during different laying periods. The abundance of Firmicutes was decreased and the abundance of Bacteroidota was increased during the peak-laying period. Functional analysis showed that the biosynthesis of secondary metabolites, amino acids, purine, and steroid hormones was altered during laying. The metabolome analysis from cecal contents showed that amino acid metabolism and steroid hormone biosynthesis changed during laying. Integrated analysis of the cecal microbiota and metabolites showed the genus Megasphaera was involved in amino acid metabolism, which included 3-phenyllatic acid, quinic acid, caffeic acid, and folic acid, and the genus Hungatella participated in steroid hormone biosynthesis through its strong correlation with estradiol. These results explored the dynamic changes in tissues related to the HPL axis and cecal microbiota and provided new insights into the interaction between the host and microbiota during egg-laying in chickens.

Terminalia Chebula Extract Replacing Zinc Oxide Enhances Antioxidant and Anti-Inflammatory Capabilities, Improves Growth Performance, and Promotes Intestinal Health in Weaned Piglets.

This study aimed to assess the effects of substituting zinc oxide with terminalia chebula extract (TCE) on growth performance, antioxidant capacity, immune function, and intestinal health in weaned pigs. Initially, 72 weaned Duroc × Landrace × Large White piglets, 28 days old with an initial weight of 7.43 ± 0.14 kg, equally divided by gender, were randomly assigned into three groups, with six replicates and four piglets per replicate. They were fed a basal diet (CON group), a diet containing 2 g/kg zinc oxide (ZnO group), or 2 g/kg TCE (TCE group) for a duration of 28 days. Subsequently, to further confirm the most appropriate levels of TCE in piglets, 96 piglets of the same breeds and age, with an initial weight of 7.42 ± 0.12 kg, also equally divided by gender, were randomly assigned into four groups, each with six replicates and four piglets per replicate, and fed a basal diet (CON group), or diets supplemented with 1 g/kg TCE (LTCE group), 2 g/kg TCE (MTCE group), or 4 g/kg TCE (HTCE group) for a duration of 28 days. The results demonstrated that both TCE and ZnO reduced diarrhea rates (p = 0.001) and enhanced average daily gain (ADG) (p = 0.014) compared to the control group. TCE at 1 g/kg and 4 g/kg reduced the feed to gain ratio (p = 0.050). Dietary supplementing with TCE and ZnO increased serum total antioxidant capacity (T-AOC) (p = 0.020). Various doses of TCE also increased jejunal IgA (p = 0.000) levels and IL-10 expression (p = 0.004), and decreased the levels of TNF-α in both serum (p = 0.043) and jejunal mucosa (p = 0.000). Notably, TCE reduced the crypt depth (CD) of the duodenal (p = 0.007) and increased the villus height (VH) of the ileal (p = 0.045), and with increased dosage, there was a rise in the villus height to crypt depth ratio (VH:CD) in the duodenum (p = 0.000) and jejunum (p = 0.001). Higher abundances of Lactobacillaceae (p = 0.000) and lower levels of Streptococcaceae (p = 0.000) and Peptostreptococcaceae (p = 0.035) in cecal contents were fed the ZnO and TCE pigs compared with CON pigs. Therefore, TCE was firstly presented as being able to replace zinc oxide, improve intestinal morphology, and enhance antioxidant and immune functions, thus safeguarding intestinal mucosal health and promoting piglet growth.

Proanthocyanidins and β-Glucan Synergistically Regulate Intestinal Inflammation in Dextran Sulfate Sodium-Induced Colitis Mice.

Proanthocyanidins (PA) have been proven to have an anti-inflammation effect in multiple models by regulating oxidative stress. β-glucan (BG) could alleviate colitis from the perspectives of intestinal permeability and gut microbiota. In the present study, the synergistic anti-inflammatory function of PA and BG was explored from multiple aspects including immune response, intestinal barrier, gut microbiota, and differential metabolites. The results showed that the supplementation of PA and BG improved the colitis symptoms including atrophy of the colon, body weight loss, and organ index increase. Additionally, inflammatory cytokine levels and oxidative stress status were significantly regulated with the intake of PA and BG. Moreover, PA and BG intervention improved intestinal permeability and promoted the expression of barrier proteins. The microbiome and metabolic profile of cecal contents showed that PA and BG supplementation increased the abundance of anti-inflammatory bacteria and decreased the abundance of pro-inflammatory bacteria. Furthermore, some beneficial metabolites involved in amino acid metabolism, carbohydrate metabolism, and biosynthesis of other secondary metabolite pathways were increased. Overall, these findings have demonstrated the regulation of the inflammatory response and remodel of metabolite profiles by PA and BG complexes, indicating that it may serve as a new strategy for inflammatory bowel disease treatment in the future.

Subchronic Chloroform Exposure Causes Intestinal Damage and Induces Gut Microbiota Disruption and Metabolic Dysregulation in Mice.

Chloroform is a prevalent toxic environmental pollutant in urban settings, posing risks to human health through exposure via various mediums such as air and tap water. The gut microbiota plays a pivotal role in maintaining host health. However, there is a paucity of research elucidating the impact of chloroform exposure on the gut microbiota. In this investigation, 18 SPF Kunming female mice were stratified into three groups (n = 6) and subjected to oral gavage with chloroform doses equivalent to 0, 50, and 150 mg/kg of body weight over 30 days. Our findings demonstrate that subchronic chloroform exposure significantly perturbs hematological parameters in mice and induces histopathological alterations in cecal tissues, consequently engendering marked disparities in the functional composition of cecal microbiota and metabolic equilibrium of cecal contents. Ultimately, our investigation revealed a statistically robust correlation, exhibiting a high degree of significance, between the intestinal microbiome composition and the metabolites that were differentially expressed consequent to chloroform exposure.

The Effects of 1-Kestose on the Abundance of Inflammation-Related Gene mRNA in Adipose Tissue and the Gut Microbiota Composition in Rats Fed a High-Fat Diet.

Chronic inflammation in adipose tissue is thought to contribute to insulin resistance, which involves the gut microbiota. Our previous studies have demonstrated that ingestion of 1-kestose can alter the gut microbiota composition, increase cecal butyrate levels, and improve insulin resistance in Otsuka Long-Evans Tokushima Fatty (OLETF) rats. Additionally, we found that 1-kestose supplementation ameliorated insulin resistance in obese rat models fed a high-fat diet (HFD), although the effects of 1-kestose on the abundance of inflammation-related gene in adipose tissue and gut microbiota composition in these rats were not explored. This study aimed to investigate the impact of 1-kestose on these parameters in HFD-fed rats, compared to OLETF rats. Male Sprague-Dawley rats were divided into two dietary groups, control or HFD, for 19 wk. Each group was further subdivided to receive either tap water or tap water supplemented with 2% (w/v) 1-kestose throughout the study. We evaluated gene expression in adipose tissue, as well as short-chain fatty acids (SCFAs) levels and microbial composition in the cecum contents. 1-Kestose intake restored the increased relative abundance of tumor necrosis factor (Tnf) mRNA in adipose tissue and the reduced level of butyrate in the cecum contents of HFD-fed rats to those observed in control diet-fed rats. Additionally, 1-kestose consumption changed the composition of the gut microbiota, increasing Butyricicoccus spp., decreasing UGC-005 and Streptococcus spp., in the cecum contents of HFD-fed rats. Our findings suggest that 1-kestose supplementation reduces adipose tissue inflammation and increases butyrate levels in the gut of HFD-fed rats, associated with changes in the gut microbiota composition, distinct from those seen in OLETF rats.

Chronic nasal inflammation early in life induces transient and long-term dysbiosis of gut microbiota in mice

The gut microbiota begins to colonize the host body following birth, develops during the suckling period and changes to the adult type after weaning. The early gut microbiota during the suckling period is thought to have profound effects on the host physiology throughout life but it is still unclear whether early dysbiosis is retained lifelong. Our previous study indicated that chronic nasal inflammation induces dysbiosis of gut microbiota in adult mice. In the present study, we addressed the question as to whether early exposure to chronic nasal inflammation induces dysbiosis, and if so, whether the dysbiosis is retained until adulthood and the sex differences in this effect. Male and female mice received repeated intranasal administration of lipopolysaccharide (LPS) or saline twice a week from P7 to P24 and were weaned at P24. The cecal contents were obtained for 16S rRNA analysis at 2 time points: at 4 weeks (wks), just after weaning, and at maturation to adulthood at 10 wks. The body weight did not differ between saline- and LPS-treated mice till around weaning, suggesting that the mothers’ milk was given similarly to all mice. At 4 wks, the beta diversity was significantly different between saline- and LPS-treated male and female mice and the composition of the gut microbiota changed in LPS-treated mice. The abundance of phylum Bacteroidota tended to decrease and that of Firmicutes increased in LPS-treated male mice, while the abundance of Deferribacterota increased in LPS-treated female mice. At 10 wks, the beta diversity was not different between saline- and LPS-treated mice, but the abundance of family Lachnospiraceae significantly decreased in LPS-treated male and female mice by LEfSe analysis. Together, chronic nasal inflammation early in life caused transient and long-term dysbiosis of gut microbiota, which may contribute to the onset and progress of metabolic and neuropsychiatric disorders.

Correlation Between Gut Microbiota Composition and Serum Interleukin 17 (IL-17) in Mice With Type 2 Diabetes and Experimental Periodontitis.

Objective To preliminarily explore the composition characteristics of gut microbiota in mice with type 2 diabetes mellitus (T2DM) and experimental periodontitis, and their correlation with serum IL-17 levels, aiming to provide new insights and evidence for related experimental studies. Methods A total of 42 SPF-grade C57BL/6J mice were randomly selected, with 24 used for T2DM modeling. Successfully modeled T2DM mice were divided into the T2DM group (ND group, n=8) and T2DM with experimental periodontitis group (PD group, n=8). Non-T2DM mice were divided into the blank control group (NC group, n=8) and the experimental periodontitis group (NP group, n=8). After modeling, body weight and fasting plasma glucose (FPG) were measured weekly. Each group of mice underwent an oral glucose tolerance test (OGTT) and an insulin tolerance test (ITT). Six weeks after modeling experimental periodontitis, serum IL-17 levels were measured using ELISA, intestinal inflammation was assessed using HE staining, and gut microbiota composition in cecal contents was analyzed by 16S rRNA sequencing to determine its correlation with serum IL-17 levels. Results FPG in the PD group was higher than in the ND group, with a statistically significant difference in the 12th week (p<0.05). The glucose tolerance level in the PD group was lower than in the ND group (p<0.01). Compared with the NC group, other groups showed varying degrees of inflammatory cell infiltration in the intestinal mucosa, and serum IL-17 levels were lower in both the ND and PD groups compared to the NC group (p<0.01), with the PD group also lower than the NP group (p<0.01). The Shannon and Pielou-e indices of gut microbiota in the PD group were significantly lower than those in the NP group (p<0.05). In terms of microbiota composition, Firmicutes were increased in both the ND and PD groups compared to the NC and NP groups (p<0.05), while Bacteroidetes were decreased (p<0.05). Proteobacteria were increased in the PD group compared to the ND group (p<0.05). The abundance of Bacteroidetes and the Bacteroidetes/Firmicutes ratio was moderately positively correlated with serum IL-17 levels (p<0.01) and moderately negatively correlated with blood glucose levels (p<0.01); serum IL-17 levels were strongly negatively correlated with blood glucose levels (p<0.01). Conclusion Comorbidity of experimental periodontitis and T2DM may exacerbate glucose metabolism impairment in T2DM mice by increasing the abundance of Proteobacteria and intestinal mucosal damage. Serum IL-17 levels may serve as an indicator of gut microbiota dysbiosis in T2DM mice with experimental periodontitis.

Chronological dynamics of the gut microbiome in response to the pasture grazing system in geese.

It is commonly accepted that dietary fibers are good for gut health. The effect of fibers on the diversity and metabolic activities of the cecal microflora, however, differ with the passage of time. Therefore, we investigated the time-series impacts of the pasture grazing system (a high dietary fiber source) on the cecal microbiome and short-chain fatty acids in Wanpu geese, comparing it to commercial feeding (a low dietary fiber source). The cecal microbiota composition and SCFA concentrations were evaluated by 16S rRNA gene sequencing and gas chromatography, respectively. We found that pasture produced a generally quick positive response to Bacteroidales, Lactobacillales, Gastranaerophilales (at 45 days), Lachnospirales, and Oscillospirales (at 60 days and 90 days) irrespective of Erysipelotrichales (at 45 days), Clostridia_UCG-014, RF39 (at 60 days), Christensenellales, and Peptostreptococcales-Tissierellales (at 90 days) in geese. Meanwhile, we found that Lactobacillales, Gastranaerophilales, Lachnospirales, and Oscillospirales were significantly correlated with short-chain fatty acids in pasture grazing geese. Indeed, the correlation of cecal microbiota with SCFAs led to altered microbial functions evinced by COG; KEGG pathway levels 1, 2, and 3; BugBase; and FAPROTAX databases. This study emphasizes the importance of dietary fiber sources in influencing beneficial impacts in regulating geese microbiota homeostasis and metabolic functions such as energy and lipid metabolism.IMPORTANCELow dietary fiber diet sources cause gut microbial and short-chain fatty acid alterations that lead to compromised animal health. The establishment of an artificial pasture grazing system at the expense of ryegrass is a good source of dietary fiber for geese. Our results described the importance of pasture in maintaining the gut microbiota, SCFAs, and potential microbial functions reported by COG; KEGG pathway levels 1, 2, and 3; BugBase; and FAPROTAX databases.

Salmonella re-engineers the intestinal environment to break colonization resistance in the presence of a compositionally intact microbiota

The gut microbiota prevents harmful microbes from entering the body, a function known as colonization resistance. The enteric pathogen Salmonella enterica serovar (S.) Typhimurium uses its virulence factors to break colonization resistance through unknown mechanisms. Using metabolite profiling and genetic analysis, we show that the initial rise in luminal pathogen abundance was powered by a combination of aerobic respiration and mixed acid fermentation of simple sugars, such as glucose, which resulted in their depletion from the metabolome. The initial rise in the abundance of the pathogen in the feces coincided with a reduction in the cecal concentrations of acetate and butyrate and an increase in epithelial oxygenation. Notably, these changes in the host environment preceded changes in the microbiota composition. We conclude that changes in the host environment can weaken colonization resistance even in the absence of overt compositional changes in the gut microbiota.

Traditional Chinese medicine formulation ChangQing compound has significant therapeutic effects on chickens infected with Eimeria tenella

Coccidiosis poses a significant challenge to the poultry industry. However, the excessive and improper use of anticoccidial drugs and vaccines has led to resistance and food safety concerns. Consequently, traditional Chinese herbs have garnered attention as a potentially safer and more effective alternative. ChangQing compound derived from various Chinese herbal medicines is a promising anticoccidiosis agent, but its therapeutic effects have not been comprehensively evaluated. This study aimed to assess the therapeutic efficacy of ChangQing Compound against Eimeria tenella-induced coccidiosis in chickens on the basis of physiological indicators, cecum lesions, and changes in microbial diversity. The comparison with the positive control group revealed the average weight gain (AWG) and anticoccidial index (ACI) of the chicks were significantly higher, in contrast, the feed conversion ratio (FCR), cecal lesion score (CLS), and oocyst count per gram of cecal content (OPG) were significantly lower (P<0.05). Notably, AWG (138.87 g), OPG (0.57 × 106), ACI (177.92), and FCR (2.51) reflected the significant therapeutic effect of the 2.5 g/L ChangQing compound treatment (CQM). Histological sections showed that the cecal villus damage and intestinal wall swelling were minimal in the CQM, consistent with the CLS (0.73). Additionally, the 2.5 g/L ChangQing compound treatment effectively prevented the decrease of red blood cells, platelets, and hemoglobin, while promoting the release of anti-inflammatory factors interleukin-10 and interleukin-4, and inhibiting the pro-inflammatory factors interferon-γ and interleukin-17. The microbial community structure in the CQM was most similar to that of the negative control group. In summary, ChangQing compound had multiple positive effects (e.g., promoting weight gain, alleviating anemia, suppressing coccidial proliferation, reducing intestinal damage, modulating immunity, and maintaining intestinal microbiota homeostasis). The study results may be relevant to developing a novel strategy for the clinical management of coccidiosis.

The effect of Lonicerae flos and Rhizoma curcumae longae extract on the intestinal development and function of broilers

This study was conducted to explore effects of Lonicerae flos and Rhomoma curcumae longae extracts (LR) on intestinal function of broilers. Three hundred broiler chickens were randomly assigned to the following five groups. The control group were fed the basal diet; the antibiotic group were fed the basal diet supplemented with spectinomycin hydrochloride (50 million units/ton) + lincomycin hydrochloride (25 g/ton); the LRH, LRM and LRL groups were fed the basal diet supplemented with a high dose (750 g/ton of feed), normal dose (500 g/ton of feed), or low dose (250 g/ton of feed) of LR, respectively. The changes of intestinal structure, intestinal digestive enzyme activities, antioxidant enzyme activities, inflammatory cytokines, and bacterial abundances in the colon and cecum contents were determined. The results indicated that compared with the control group and the antibiotic group, LR significantly increased the villus length/crypt depth (VCR) of the intestine, and significantly inhibited oxidative stress and inflammatory responses in the broiler intestine. In addition, LR regulated intestinal function by increasing the abundance of the intestinal microorganisms in broilers. In conclusion, LR improved antioxidant capacity, intestinal morphology, and microorganisms, and inhibited inflammatory response. The effect of high and medium doses of LR was better than lower doses.

Radix Isatidis polysaccharide (RIP) alleviates QX-genotype infectious bronchitis virus-induced interstitial nephritis through the Nrf2/NLRP3/Caspase-3 signaling pathway

Interstitial nephritis is the primary cause of mortality in IBV-infected chickens. Our previous research has demonstrated that Radix Isatidis polysaccharide (RIP) could alleviate this form of interstitial nephritis. To explore the mechanism, SPF chickens and chicken embryonic kidney cells (CEKs) were pre-treated with RIP and subsequently infected with QX-genotype IBV strain. Kidneys were sampled for transcriptomic and metabolomic analyses, and the cecum contents were collected for 16S rRNA gene sequencing. Results showed that pre-treatment with RIP led to a 50 % morbidity reduction in infected-chickens, along with decreased tissue lesion and viral load in the kidneys. Multi-omics analysis indicated three possible pathways (including antioxidant, anti-inflammatory and anti-apoptosis) which associated with RIP's efficacy against interstitial nephritis. Following further validation both in vivo and in vitro, the results showed that pre-treatment with RIP could activate the antioxidant transcription factor Nrf2, stimulate antioxidant enzyme expression, and consequently inhibit oxidative stress. Pre-treatment with RIP could also significantly reduce the expression of NLRP3 inflammasome and apoptosis-associated proteins (including Bax, Caspase-3, and Caspase-9). Additionally, RIP was also observed to promote the growth of beneficial bacteria in the intestine. Overall, pretreatment with RIP can alleviate QX-genotype IBV-induced interstitial nephritis via the Nrf2/NLRP3/Caspase-3 signaling pathway. This study lays the groundwork for the potential use of RIP in controlling avian infectious bronchitis (IB).

Decreasing light exposure increases the abundance of antibiotic resistance genes in the cecum and feces of laying hens

The gut microbiome plays a crucial role in maintaining animal health and is influenced by various factors, including light exposure; however, the response in laying hens of the gut microbiome to intermittent light regimes and the related impact on antibiotic resistance genes (ARGs) remain poorly understood. In this study, we divided 20-week-old laying hens into two groups. These groups were exposed to either continuous normal light or intermittent light for 8 weeks. The feces and cecal contents of laying hens were collected for analysis. Metagenomic analysis of both feces and cecal content samples revealed significant shifts in the microbial composition and abundance of ARGs under intermittent light exposure compared to normal light exposure (P < 0.05). Furthermore, metabolomic analysis of the cecal contents revealed substantial alterations in the abundance and composition of ARGs and mobile genetic elements (MGEs) in response to intermittent light exposure (P < 0.05). Network analysis revealed intricate co-occurrence patterns among bacterial communities, metabolites, and ARGs, highlighting correlations between Bacteroidetes species, ARGs, and metabolites. Although certain bacterial species showed differential associations, the dominant bacteria carrying ARGs or MGEs had relatively low numbers, suggesting that other bacterial communities may have had a greater influence on ARG dissemination. Moreover, our observations highlight the crucial role of metabolites as mediators between bacterial communities and ARGs, providing novel insights into the dynamics of antibiotic resistance development. Our findings underscore the impact of intermittent light exposure on ARG proliferation in poultry farming and emphasize interconnections among ARGs, bacterial communities, and metabolic pathways. The results underscore the importance of considering both microbial communities and metabolic processes to understand antibiotic resistance in agricultural settings.

Effect of High Dietary Iron on Fat Deposition and Gut Microbiota in Chickens.

To meet the demand of consumers for chicken products, poultry breeders have made improvements to chickens. However, this has led to a new problem in the modern poultry industry, namely excessive fat deposition. This study aims to understand the effects of dietary iron supplementation on fat deposition and gut microbiota in chickens. In this study, we investigated the effects of iron on the growth performance, fat deposition, and gut microbiota of silky fowl black-bone chickens. A total of 75 7-week-old silky fowl black-bone chickens were randomly divided into three groups (five replicates per group, five chickens per replicate) and fed them for 28 days using a growing diet (control group), a growing diet + 10% tallow (high-fat diet group, HFD group), and a growing diet + 10% tallow + 500 mg/kg iron (HFDFe500 group), respectively. We detected the effects of iron on the growth performance, fat deposition, and gut microbiota of silky fowl black-bone chickens using the growth performance index test, oil red O staining, and HE staining, and found that the high-fat diet significantly increased liver and serum fat deposition and liver injury, while the addition of iron to the diet could reduce the fat deposition caused by the high-fat diet and alleviate liver injury. In addition, 16S rDNA sequencing was used to compare the relative abundance of gut microbiota in the cecal contents in different feeding groups. The results showed that the high-fat diet could induce gut microbiota imbalance in chickens, while the high-iron diet reversed the gut microbiota imbalance. PICRUSt functional prediction analysis showed that dietary iron supplementation affected amino acid metabolism, energy metabolism, cofactors, and vitamin metabolism pathways. In addition, correlation analysis showed that TG was significantly associated with Firmicutes and Actinobacteriota (p < 0.05). Overall, these results revealed high dietary iron (500 mg/kg) could reduce fat deposition and affect the gut microbiota of silky fowl black-bone chickens, suggesting that iron may regulate fat deposition by influencing the gut microbiota of chickens and provides a potential avenue that prevents excessive fat deposition in chickens by adding iron to the diet.

Investigation into the supplementation of a ferric sillen core-linked polymer on the health and physiological performance of broiler chickens

Poultry is a ubiquitous and highly sought-after protein source valued for its accessibility, notable protein content, and lack of religious constraints. However, the demand for poultry has resulted in a surge in intensive production practices. The transition from subsistence agricultural practices to intensive food production resulted in the widespread adoption of antibiotics for both therapeutic and economic purposes. These interventions were intended to enhance meat yield, promote bird health, and enhance cost-effectiveness of production. However, this inadvertently contributed to the rise of antimicrobial resistance (AMR). Therefore, the need to explore alternative approaches to mitigate the problems associated with AMR has become increasingly pressing. In response, metal-based compounds have emerged as a promising substitute to conventional antibiotics. In this study, the effects of a water soluble metallo-antimicrobial supplement, ferric sillen core-linked polymer (FSCLP), on body weight gain, feed conversion, water intake, volatile fatty acid (VFA) production, cecal microbiome and intestinal morphology in broilers was examined. The findings of this study suggested that the addition of the FSCLP resulted in better bird performance, even during a period of heat stress. Volatile fatty acids (VFA) analysis of cecal contents indicated that there were significantly higher levels (p < 0.05) of butyric and valeric acids. Cecal microbiome analysis confirmed significantly lower abundance (p < 0.05) of Proteobacteria (e.g., E. coli) and a significantly greater abundance of VFA-producing bacteria such as Intestinimonas butyriciproducens, Blautia and Lachnospiraceae. The intestinal morphology data showed supplementation with the FSCLP at 80 ppm resulted in a significantly higher (p < 0.05) villus height of the jejunum.This study emphasises the potential of FSCLP as a feasible solution to the issues faced by AMR in chicken production, providing insights into its beneficial impacts on performance, microbial composition, and intestinal health.

Dietary supplementation with 25-hydroxyvitamin D3 regulates productive performance, lipid metabolism and gut microbiota in aged laying ducks

The aim of this study was to investigate the effect of dietary supplementation with 25-hydroxyvitamin D3 (25(OH)D3) on productive performance, lipid metabolism and gut microbiota in aged laying ducks. A total of 432 healthy Longyan ducks at 60-week of age were randomly allotted to 6 groups, each with 6 replicates of 12 ducks. Ducks were given a basal diet (without added 25(OH)D3) or that diet supplemented with 800, 1600, 2400, 3200, or 4000 IU/kg 25(OH)D3 for a total of 16 wk. Dietary supplementation with 25(OH)D3 improved egg production, egg mass and average daily feed intake, and decreased the feed conversion ratio (FCR) of ducks during the whole trial period (linear, quadratic; P < 0.05). Supplementation with 25(OH)D3 decreased very low-density lipoprotein (VLDL) content in yolk (P = 0.008), decreased high-density lipoprotein and low-density lipoprotein (LDL) content in plasma (P = 0.002). Hepatic index, VLDL, LDL, triglyceride and total cholesterol content in liver, nonalcoholic fatty liver activity score of liver and alanine aminotransferase content in plasma were decreased with supplementation of 25(OH)D3 (linear or quadratic; P < 0.05). The decreased hepatic apolipoprotein B 100 and lipoprotein lipase expression, and increased hepatic peroxisome proliferator-activated receptor-α and sterol regulatory element binding protein-1 expression resulted from 25(OH)D3 supplementation (linear, quadratic; P < 0.05). Moreover, 25(OH)D3 supplementation increased the villus/crypt ratio (linear, quadratic; P < 0.05) and expression of zonula occludens protein 1 and nuclear factor-κ-gene binding in duodenum (P < 0.05). The supplementation of 25(OH)D3 reduced the abundance of Wittenberg polluted soil-2 bacteria, Synergistota, Bacteroidales, Colidextribacter, Eggerthellaceae, Oscillospira, Oscillibacter, UCG-009, Barnesiellaceae and Lachnospiraceae_UCG-010 in cecal contents (P < 0.05). Dietary requirements for 25(OH)D3 for ducks (60 to 76 wk), were estimated to be 3377 IU/kg for egg production, 3434 IU/kg for egg mass, and 3256 IU/kg for FCR. In summary, dietary 25(OH)D3 supplementation improved productive performance and influenced liver and plasma lipid homeostasis in aged laying ducks, which may be associated with the reduction of bacteria involved in carbohydrate metabolism in the cecum. Supplementing the basal diet with 3250 to 3450 IU/kg 25(OH)D3 is recommended for aged laying ducks (60 to 76 wk).

The effect of peanut skins as a natural antimicrobial feed additive on ileal and cecal microbiota in broiler chickens inoculated with Salmonella enterica Enteritidis

The consumption of poultry products contaminated with Salmonella species is one of the most common causes of Salmonella infections. In vivo studies demonstrated the potential application of peanut skins (PS) as an antimicrobial poultry feed additive to help mitigate the proliferation of Salmonella in poultry environments. Tons of PS, a waste by-product of the peanut industry, are generated and disposed in U.S. landfills annually. Peanut skins and extracts have been shown to possess antimicrobial and antioxidant properties. Hence, we aimed to determine the effect of PS as a feed additive on the gut microbiota of broilers fed a control or PS supplemented (4% inclusion) diet and inoculated with or without Salmonella enterica Enteritidis (SE). At hatch 160 male broilers were randomly assigned to 4 treatments: 1) CON-control diet without SE, 2) PS-PS diet without SE, 3) CONSE-control diet with SE, 4) PSSE-PS diet with SE. On d 3, birds from CONSE and PSSE treatments were inoculated with 4.2 × 109 CFU/mL SE. At termination (4 wk), 10 birds/treatment were euthanized and ileal and cecal contents were collected for 16S rRNA analysis using standard methodologies. Sequencing data were analyzed using QIIME2. No effect of PS or SE was observed on ileal alpha and beta diversity, while evenness, richness, number of amplicon sequence variants (ASV) and Shannon, as well as beta diversity were significantly (P < 0.05) affected in ceca. Similarly, more differentially abundant taxa between treatment groups were identified in ceca than in ileum. However, more microbiota functional changes, based on the PICRUST2 prediction, were observed in ileum. Overall, relatively minor changes in microbiota were observed during SE infection and PS treatment, suggesting that PS addition may not attenuate the SE proliferation, as shown previously, through modulation of microbiota in gastrointestinal tract. However, while further studies are warranted, these results suggest that PS may potentially serve as a functional feed additive for poultry for improvement of animal health.