Akkermansia muciniphila Enhances Egg Quality and the Lipid Profile of Egg Yolk by Improving Lipid Metabolism

Effects of a new compound probiotic on growth performance, antioxidant capacity, intestinal health, gut microbiota and metabolites of broilers

Compound probiotics have gained increasing recognition as feed additives for improving feed conversion ratio and intestinal health of broilers. Two Lactobacillus strains (Ligilactobacillus salivarius CML391 and Limosilactobacillus reuteri CML393) and two Bacillus strains (Bacillus velezensis CML396 and Bacillus paralicheniformis CML399) were isolated from broiler intestines and combined to form a new compound probiotic (referred to as "CML compound probiotic"). The effects of CML compound probiotic on broiler growth performance, antioxidant capacity, intestinal health, cecal microbiota, and microbial-derived metabolites were assessed in this study. A total of 120 male Arbor Acres chicks were randomly divided into two groups: a control group (CON) fed a basal diet and a CML group supplemented with the compound probiotic at 10⁹ CFU/kg of diet. Dietary supplementation with CML compound probiotic promoted broiler growth performance, enhanced antioxidant capacity, and improved intestinal health. Furthermore, the CML compound probiotic modulated the cecal microbiota by increasing beneficial bacteria such as Bacteroides, Phocea and Defluviitaleaceae UCG-011, and significantly elevated the concentrations of short-chain fatty acids (SCFAs). Metabolomic analysis revealed that the CML compound probiotic influenced lipid metabolism pathways, particularly glycerophospholipid and linoleic acid metabolism. In conclusion, this study indicated that the CML compound probiotic represents a valuable strategy for optimizing broiler growth performance and intestinal health.

Goose Deoxycholic Acid Ameliorates Liver Injury in Laying Hens with Fatty Liver Hemorrhage Syndrome by Inhibiting the Inflammatory Response

Fatty liver hemorrhagic syndrome (FLHS) in laying hens is a nutritional and metabolic disease involving liver enlargement, hepatic steatosis, and hepatic hemorrhage as the primary symptoms. The syndrome is prone to occur during the peak laying period of laying hens, which has resulted in significant economic losses in the laying hen breeding industry; however, the specific pathogenesis of FLHS remains unclear. Our group and previous studies have shown that bile acid levels are significantly decreased during the development of fatty liver and that targeted activation of bile acid-related signaling pathways is beneficial for preventing and treating fatty liver. In this study, we generated a FLHS laying hen model by feeding hens a high-energy, low-protein diet, with goose deoxycholic acid (CDCA) given as an intervention. HE staining, fluorescence quantitative PCR, and ELISA were used to evaluate the effects of CDCA on pathological changes and inflammatory responses in the liver. The results showed that hepatic hemorrhage in FLHS laying hens was reduced after CDCA treatment. Furthermore, fat vacuoles and transaminase levels decreased significantly. In addition, expression levels of M1-type macrophage markers and polarization products were significantly reduced, and the expression of pro-inflammatory regulatory factors related to the JAK-STAT signaling pathway, LPS-TLR4-Myd88-NF-kB signaling pathway, and NLRP3 inflammasomes decreased significantly as well. Expression levels of M2-type macrophage markers and polarization products increased significantly, as did the expression of anti-inflammatory regulators related to the JAK-STAT signaling pathway. These results suggest that CDCA ameliorates liver injury in laying hens with FLHS by inhibiting macrophage M1-type polarization and the resulting pro-inflammatory response, thereby promoting M2-type macrophage polarization and an anti-inflammatory response.

Investigating the Effects of Dietary Bile Acids on Production Performance and Lipid Metabolism in Late-Phase Laying Hens

Multiply adverse effects including declines in production performance and excessive fat deposition were noticed with the extension of the laying cycle in hens, which are pertinent to animal welfare and human food safety. This study aimed to investigate the effect of dietary supplementation of bile acids (BAs) on production performance and lipid metabolism in late-phase laying hens. A total of 144 70-week-old hens were distributed into three treatments with eight replicates per treatment, including the basal diet with 0 (Ctrl), 95.01 (Low-BA), and 189.99 mg/kg (High-BA) of porcine BAs, respectively. The test period was from 70 to 75 weeks. The supplementation of BAs did not significantly alter laying performance during the trial, whereas it increased (p < 0.05) the total follicles compared to the Ctrl diet. The eggs from the hens fed the BA diet exhibited increased (p > 0.05) relative weight of eggshell and yolk color than those that consumed the Ctrl diet. There were no significant changes following BA treatment regarding the serum lipid profile. Dietary BA treatment reduced the total triglyceride in livers to different extents, resulting in the decreased diameter and area of vacuoles in liver tissues. The low-dose BA treatment decreased the mRNA levels of fatty acid synthase (FASN) and stearoyl-CoA desaturase (SCD), while promoting the expression of lipoprotein lipase (LPL) compared to the Ctrl group (both p < 0.05). Of note, the expressions of farnesoid X receptor (FXR), apical sodium-dependent bile acid transporter (ASBT), and ileum bile acid-binding protein (IBABP) were notably downregulated (p < 0.05) by the low-dose BA treatment. Dietary BA treatment had no apparent effects on laying performance, whereas it increased the follicle frequency, eggshell weight, and yolk color. Moreover, a diet containing 95.01 mg/kg of BAs depressed ileal BA resorption and hepatic fatty deposition by reducing lipogenesis and promoting lipolysis, which may have a beneficial effect on the liver in late-phase layers.

Compound Bacillus improves eggshell quality and egg metabolites of hens by promoting the metabolism balance of calcium and phosphorus and uterine cell proliferation

Probiotics have beneficial effects on improving egg quality, but there is little research about the effect of probiotics on metabolite composition, and the mechanisms are not yet fully understood. The aim of this study was to investigate the potential mechanisms by which compound Bacillus improves egg quality and metabolite composition. A total of 20,000 Jingfen No. 6 laying hens at 381 d old were randomly divided into two treatments: control group with a basal diet, and the basal diet with 5 × 108 CFU/kg compound Bacillus supplementation (Ba) group. The trial lasted eight weeks. The results showed that compound Bacillus improved the gloss and strength of eggshells and reduced the ratio of sand-shell eggs by 23.8%. Specifically, the effective layer of eggshell was thicker and its calcite column was closely connected. Compound Bacillus increased the contents of beneficial fatty acids in the egg yolk, and lipids and lipid-like molecules in the albumen (P < 0.01), while decreased the contents of total cholesterol, triglycerides, and benzene ring compounds in the egg yolk and organic oxygen compounds in the albumen (P < 0.01). In addition, the compound Bacillus increased the calcium absorption in the duodenum by up-regulating the expression of transporters and serum hormone synergism (P < 0.05), and promoted metabolic balance of calcium and phosphorus. Simultaneously, uterine transcriptome showed that the expression of ChaC glutathione specific gamma-glutamylcyclotransferase 1 (CHAC1), glycoprotein-N-acetylgalactosamine 3-beta-galactosyltransferase 1 (C1GALT1), phosphatidylinositol-4-phosphate 5-kinase type 1 beta (PIP5K1B), methylenetetrahydrofolate dehydrogenase 2 (MTHFD2), brain enriched myelin associated protein 1 (BCAS1), and squalene epoxidase (SQLE) genes were increased (P < 0.01), indicating that nutrient metabolism activity was enhanced. The expression of the BCAS1, C1GALT1, KLF transcription factor 13 (KLF13), and leucine rich repeat neuronal 1 (LRRN1) was increased (P < 0.01), indicating that the cell proliferation was enhanced, which slowed uterus aging. In conclusion, compound Bacillus improved the eggshell strength and metabolite composition in the egg by promoting metabolic balance of calcium and phosphorus, cell proliferation, and nutrient metabolism in the uterus.

Anaerostipes caccae CML199 enhances bone development and counteracts aging-induced bone loss through the butyrate-driven gut-bone axis: the chicken model

BACKGROUND

The gut microbiota is a key regulator of bone metabolism. Investigating the relationship between the gut microbiota and bone remodeling has revealed new avenues for the treatment of bone-related disorders. Despite significant progress in understanding gut microbiota-bone interactions in mammals, research on avian species remains limited. Birds have unique bone anatomy and physiology to support egg-laying. However, whether and how the gut microbiota affects bone physiology in birds is still unknown. In this study, we utilized laying hens as a research model to analyze bone development patterns, elucidate the relationships between bone and the gut microbiota, and mine probiotics with osteomodulatory effects.

RESULTS

Aging led to a continuous increase in bone mineral density in the femur of laying hens. The continuous deposition of medullary bone in the bone marrow cavity of aged laying hens led to significant trabecular bone loss and weakened bone metabolism. The cecal microbial composition significantly shifted before and after sexual maturity, with some genera within the class Clostridia potentially linked to postnatal bone development in laying hens. Four bacterial strains associated with bone development, namely Blautia coccoides CML164, Fournierella sp002159185 CML151, Anaerostipes caccae CML199 (ANA), and Romboutsia lituseburensis CML137, were identified and assessed in chicks with low bacterial loads and chicken primary osteoblasts. Among these, ANA demonstrated the most significant promotion of bone formation both in vivo and in vitro, primarily attributed to butyrate in its fermentation products. A long-term feeding experiment of up to 72 weeks confirmed that ANA enhanced bone development during sexual maturity by improving the immune microenvironment of the bone marrow in laying hens. Dietary supplementation of ANA for 50 weeks prevented excessive medullary bone deposition and mitigated aging-induced trabecular bone loss.

CONCLUSIONS

These findings highlight the beneficial effects of ANA on bone physiology, offering new perspectives for microbial-based interventions for bone-related disorders in both poultry and possibly extending to human health. Video Abstract.

Hepatoprotective effects of magnolol in fatty liver hemorrhagic syndrome hens through shaping gut microbiota and tryptophan metabolic profile

BACKGROUND

Magnolol (MAG) exhibits hepatoprotective activity, however, whether and how MAG regulates the gut microbiota to alleviate fatty liver hemorrhagic syndrome (FLHS) remains unclear. Therefore, we investigated the mechanism of MAG in FLHS laying hens with an emphasis on alterations in the gut-liver axis. We randomly divided 540 56-week-old Hy-line white laying hens with FLSH into 4 groups. The birds were fed a high-fat low-protein (HFLP) diet (CON) or HELP diets supplemented with 200, 400, and 600 mg/kg of MAG (M1, M2, and M3, respectively) for 9 weeks.

RESULTS

Magnolol supplementation increased the laying rate and ameliorated hepatic damage and dysfunction by regulating lipid metabolism, improving intestinal barrier function, and shaping the gut microbiota and tryptophan metabolic profiles. Dietary MAG supplementation downregulated the expression of lipid synthesis genes and upregulated the expression of lipid transport genes at varying degrees. The intestinal barrier function was improved by 200 and 400 mg/kg of MAG supplementation, as evidenced by the increased villus height and mRNA expression of tight junction related genes. Microbiological profile information revealed that MAG changed the gut microbiota, especially by elevating the abundances of Lactobacillus, Faecalibacterium, and Butyricicoccus. Moreover, non-targeted metabolomic analysis showed that MAG significantly promoted tryptophan metabolites, which was positively correlated with the MAG-enriched gut microbiota. The increased tryptophan metabolites could activate aryl hydrocarbon receptor (AhR) and relieved hepatic inflammation and immune response evidenced by the downregulated the gene expression levels of pro-inflammatory cytokines such as interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) in the liver. The fecal microbiota transplantation (FMT) experiments further confirmed that the hepatoprotective effect is likely mediated by MAG-altered gut microbiota and their metabolites.

CONCLUSIONS

Magnolol can be an outstanding supplement for the prevention and mitigation of FLHS in laying hens by positively regulating lipid synthesis and transport metabolism, improving the intestinal barrier function, and relieving hepatic inflammation by reshaping the gut microbiota and metabolite profiles through gut microbiota-indole metabolite-hepatic AhR crosstalk. These findings elucidate the mechanisms by which MAG alleviates FLHS and provide a promising method for preventing liver diseases by modulating gut microbiota and their metabolites.

Prevotella and succinate treatments altered gut microbiota, increased laying performance, and suppressed hepatic lipid accumulation in laying hens

BACKGROUND

This work aimed to investigate the potential benefits of administering Prevotella and its primary metabolite succinate on performance, hepatic lipid accumulation and gut microbiota in laying hens.

RESULTS

One hundred and fifty 58-week-old Hyline Brown laying hens, with laying rate below 80% and plasma triglyceride (TG) exceeding 5 mmol/L, were used in this study. The hens were randomly allocated into 5 groups and subjected to one of the following treatments: fed with a basal diet (negative control, NC), oral gavage of 3 mL/hen saline every other day (positive control, PC), gavage of 3 mL/hen Prevotella melaninogenica (107 CFU/mL, PM) or 3 mL/hen Prevotella copri (107 CFU/mL, P. copri) every other day, and basal diet supplemented with 0.25% sodium succinate (Succinate). The results showed that PM and P. copri treatments significantly improved laying rate compared to the PC (P < 0.05). The amount of lipid droplet was notably decreased by PM, P. copri, and Succinate treatments at week 4 and decreased by P. copri at week 8 (P < 0.05). Correspondingly, the plasma TG level in Succinate group was lower than that of PC (P < 0.05). Hepatic TG content, however, was not significantly influenced at week 4 and 8 (P > 0.05). PM treatment increased (P < 0.05) the mRNA levels of genes PGC-1β and APB-5B at week 4, and ACC and CPT-1 at week 8. The results indicated enhanced antioxidant activities at week 8, as evidenced by reduced hepatic malondialdehyde (MDA) level and improved antioxidant enzymes activities in PM and Succinate groups (P < 0.05). Supplementing with Prevotella or succinate can alter the cecal microbiota. Specifically, the abundance of Prevotella in the Succinate group was significantly higher than that in the other 4 groups at the family and genus levels (P < 0.05).

CONCLUSIONS

Oral intake of Prevotella and dietary supplementation of succinate can ameliorate lipid metabolism of laying hens. The beneficial effect of Prevotella is consistent across different species. The finding highlights that succinate, the primary metabolite of Prevotella, represents a more feasible feed additive for alleviating fatty liver in laying hens.

Effects of different selenium sources and levels on the physiological state, selenoprotein expression, and production and preservation of selenium-enriched eggs in laying hens

Selenium (i.e., Se) is a trace element that is vital in poultry nutrition, and optimal forms and levels of Se are critical for poultry productivity and health. This study aimed to compare the effects of sodium selenite (SS), yeast selenium (SY), and methionine selenium (SM) at selenium levels of 0.15 mg/kg and 0.30 mg/kg on production performance, egg quality, egg selenium content, antioxidant capacity, immunity and selenoprotein expression in laying hens. The trial was conducted in a 3 × 2 factorial arrangement, and a total of 576 forty-three-wk-old Hyland Brown laying hens were randomly assigned into 6 treatment groups, with diets supplemented with 0.15 mg Se/kg and 0.3 mg Se/kg of SS, SY and SM for 8 wk, respectively. Results revealed that SM increased the laying rate compared to SS and SY (P < 0.05), whereas different selenium levels had no effect. Organic selenium improved egg quality, preservation performance, and selenium deposition compared to SS (P < 0.05), while SY and SM had different preferences for Se deposition in the yolk and albumen. Also, organic selenium enhanced the antioxidant capacity and immune functions of laying hens at 0.15 mg Se/kg, whereas no obvious improvement was observed at 0.30 mg Se/kg. Moreover, SY and SM increased the mRNA expression of most selenoproteins compared to SS (P < 0.05), with SM exhibiting a more pronounced effect. Correlation analysis revealed a strong positive association between glutathione peroxidase 2 (GPx2), thioredoxin reductases (TrxRs), selenoprotein K (SelK), selenoprotein S (SelS), and antioxidant and immune properties. In conclusion, the use of low-dose organic selenium is recommended as a more effective alternative to inorganic selenium, and a dosage of 0.15 mg Se/kg from SM is recommended based on the trail conditions.

Sodium Butyrate Alleviates Free Fatty Acid-Induced Steatosis in Primary Chicken Hepatocytes via Regulating the ROS/GPX4/Ferroptosis Pathway

Fatty liver hemorrhagic syndrome (FLHS) in laying hens is a nutritional metabolic disease commonly observed in high-yielding laying hens. Sodium butyrate (NaB) and ferroptosis were reported to contribute to the pathogenesis of fatty liver-related diseases. However, the underlying mechanism of NaB in FLHS and whether it mediates ferroptosis remains unclear. A chicken primary hepatocyte induced by free fatty acids (FFAs, keeping the ratio of sodium oleate and sodium palmitate concentrations at 2:1) was established, which received treatments with NaB, the ferroptosis inducer RAS-selective lethal 3 (RSL3), and the inhibitor ferrostatin-1 (Fer-1). As a result, NaB increased biochemical and lipid metabolism indices, and the antioxidant level, while inhibiting intracellular ROS accumulation and the activation of the ferroptosis signaling pathway, as evidenced by a reduction in intracellular iron concentration, upregulated GPX4 and xCT expression, and inhibited NCOA4 and ACSL4 expression. Furthermore, treatment with Fer-1 reinforced the protective effects of NaB, while RSL3 reversed it by blocking the ROS/GPX4/ferroptosis pathway, leading to the accumulation of lipid droplets and oxidative stress. Collectively, our findings demonstrated that NaB protects hepatocytes by regulating the ROS/GPX4-mediated ferroptosis pathway, providing a new strategy and target for the treatment of FLHS.

Dietary Morus alba L. leaf supplementation improves hepatic lipid accumulation of laying hens via downregulating CircACACA

Fatty liver hemorrhagic syndrome (FLHS) is the most common metabolic disease in laying hens. Morus alba L. (mulberry) leaf has the effect of regulating lipid metabolism. We evaluated the effects of dietary 3% mulberry leaf (MUL) supplementation in production performance, egg quality, and liver lipid deposition in laying hens. Differentially expressed genes and circRNAs in the liver were identified using whole-transcriptome sequencing. We also evaluated the effects of the MUL extract using an in vitro model of primary hepatocytes induced by free fatty acids and explored the role of key circRNAs in this process. Dietary supplementation with 3% MUL alleviated liver steatosis in laying hens, as shown by decreased fatty liver color score, relative liver weight (P < 0.01), and triglyceride levels (P < 0.05), and showed a tendency to reduce the mortality rate of laying hens (P = 0.09). In addition, mulberry leaf supplementation significantly reduced cholesterol content in egg yolk (P < 0.01). Dietary mulberry leaf supplementation downregulated the expression of genes involved in fatty acid and cholesterol biosynthesis, and upregulated the expression of fatty acid oxidation-related genes in the liver. CircACACA, which is derived from exons 2 and 3 of the acetyl-CoA carboxylase alpha (ACACA) pre-mRNA, was significantly reduced in the MUL group (P < 0.01). Upregulation of circACACA expression reversed the lipid-lowering effect of mulberry leaf extract by upregulating sterol regulatory element-binding proteins 1 c (SREBP-1c) and fatty acid synthase (FASN) (P < 0.05). Overall, mulberry leaf is an effective therapeutic strategy for FLHS in hens and can improve liver lipid metabolism by downregulating circACACA.

Genome-Assisted Probiotic Characterization and Application of Lactiplantibacillus plantarum 18 as a Candidate Probiotic for Laying Hen Production

Probiotics gained significant attention for their potential to improve gut health and enhance productivity in animals, including poultry. This comprehensive study focused on the genetic analysis of Lactiplantibacillus plantarum 18 (LP18) to understand its survival and colonization characteristics in the gastrointestinal tract. LP18 was supplemented in the late-stage diet of laying hens to investigate its impact on growth performance, egg quality, and lipid metabolism. The complete genome sequence of LP18 was determined, consisting of 3,275,044 base pairs with a GC content of 44.42% and two circular plasmids. Genomic analysis revealed genes associated with adaptability, adhesion, and gastrointestinal safety. LP18 supplementation significantly improved the daily laying rate (p < 0.05) during the late-production phase and showed noteworthy advancements in egg quality, including egg shape index (p < 0.05), egg albumen height (p < 0.01), Haugh unit (p < 0.01), and eggshell strength (p < 0.05), with notable improvements in eggshell ultrastructure. Additionally, LP18 supplementation resulted in a significant reduction in serum lipid content, including LDL (p < 0.01), FFA (p < 0.05), and Gly (p < 0.05). These findings provide valuable insights into the genomic characteristics of LP18 and the genes that support its survival and colonization in the gastrointestinal tract. Importantly, this study highlights the potential of LP18 as a probiotic candidate to enhance productivity, optimize egg quality, and modulate lipid metabolism in poultry production.

Ginkgo biloba extract alleviates fatty liver hemorrhagic syndrome in laying hens via reshaping gut microbiota

BACKGROUND

Ginkgo biloba extract (GBE) is evidenced to be effective in the prevention and alleviation of metabolic disorders, including obesity, diabetes and fatty liver disease. However, the role of GBE in alleviating fatty liver hemorrhagic syndrome (FLHS) in laying hens and the underlying mechanisms remain to be elucidated. Here, we investigated the effects of GBE on relieving FLHS with an emphasis on the modulatory role of GBE in chicken gut microbiota.

RESULTS

The results showed that GBE treatment ameliorated biochemical blood indicators in high-fat diet (HFD)-induced FLHS laying hen model by decreasing the levels of TG, TC, ALT and ALP. The lipid accumulation and pathological score of liver were also relieved after GBE treatment. Moreover, GBE treatment enhanced the antioxidant activity of liver and serum by increasing GSH, SOD, T-AOC, GSH-PX and reducing MDA, and downregulated the expression of genes related to lipid synthesis (FAS, LXRα, GPAT1, PPARγ and ChREBP1) and inflammatory cytokines (TNF-α, IL-6, TLR4 and NF-κB) in the liver. Microbial profiling analysis revealed that GBE treatment reshaped the HFD-perturbed gut microbiota, particularly elevated the abundance of Megasphaera in the cecum. Meanwhile, targeted metabolomic analysis of SCFAs revealed that GBE treatment significantly promoted the production of total SCFAs, acetate and propionate, which were positively correlated with the GBE-enriched gut microbiota. Finally, we confirmed that the GBE-altered gut microbiota was sufficient to alleviate FLHS by fecal microbiota transplantation (FMT).

CONCLUSIONS

We provided evidence that GBE alleviated FLHS in HFD-induced laying hens through reshaping the composition of gut microbiota. Our findings shed light on mechanism underlying the anti-FLHS efficacy of GBE and lay foundations for future use of GBE as additive to prevent and control FLHS in laying hen industry.

The effects of supplementation of probiotics, prebiotics, or synbiotics on patients with non-alcoholic fatty liver disease: A meta-analysis of randomized controlled trials

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease. Research on the efficacy of probiotics, prebiotics, and synbiotics on NAFLD patients continues to be inconsistent. The purpose of this study is to evaluate the effectiveness of these microbial therapies on NAFLD.

METHODS

Eligible randomized-controlled trials reporting the effect of probiotics, prebiotics, or synbiotics in NAFLD were searched in PubMed, Web of Science, Embase, Google scholar, and CNKI databases from 2020 to Jul 2022. The changes in the outcomes were analyzed using standard mean difference (SMD) and 95% confidence intervals (CIs) with a random- or fixed-effects model to examine the effect of microbial therapies. Subgroup analysis, influence and publication bias analysis were also performed. The quality of the eligible studies was evaluated using the Cochrane Risk of Bias Tool.

RESULTS

Eleven studies met the inclusion criteria involving 741 individuals. Microbial therapies could improve liver steatosis, total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL-c), alanine aminotransferase (ALT), alkaline phosphatase (ALP), glutamyl transpeptidase (GGT), and homeostasis model assessment-insulin resistance (HOMAI-R) (all P < 0.05). But microbial therapies could not ameliorate body mass index (BMI), energy, carbohydrate, fat intake, fasting blood sugar, HbA1c, insulin, high-sensitivity C-reactive protein (hs-CRP), and hepatic fibrosis of patients with NAFLD.

CONCLUSION

Probiotics, prebiotics, and synbiotics supplementation can potentially improve liver enzymes, lipid profiles, and liver steatosis in patients with NAFLD.