Intrauterine growth retardation affects liver bile acid metabolism in growing pigs: effects associated with the changes of colonic bile acid derivatives

Adrenal High-Expressional CYP27A1 Mediates Bile Acid Increase and Functional Impairment in Adult Male Offspring by Prenatal Dexamethasone Exposure

Prenatal dexamethasone exposure (PDE) can impact adrenal corticosteroid synthesis in adult offspring. Furthermore, the adrenal gland can autonomously synthesize bile acids, but local bile acids accumulation has cytotoxic effects. This study found that PDE increased histone 3 lysine 27 acetylation (H3K27ac) levels in the promoter region of cholesterol 27 hydroxylase (CYP27A1) and its expression, as well as total bile acids (TBA) concentrations and enhanced endoplasmic reticulum stress (ERS) and inhibit steroid synthesis in adult male offspring rat adrenal glands. However, it is reversed in females. Tracing back to the prenatal stage and in combination with cellular experiments, it is further revealed that dexamethasone can regulate glucocorticoid receptor (GR)/SET binding protein 1 (SETBP1)/CYP27A1 signal pathway, consequently cause intracellular increase of bile acids. Finally, administration of nilvadipine (CYP27A1 inhibitor) to male offspring for 4 weeks after birth resulted in the reversal of PDE-induced adrenal morphological and functional damage. In conclusion, PDE induces fetal adrenal corticosteroid dysfunction in adult male offspring by upregulating CYP27A1 promoter region H3K27ac levels and expression in the adrenal gland through the GR/SETBP1 signaling pathway. This effect persists beyond birth, leading to bile acids local increase and subsequent enhancement of ERS, ultimately inducing cellular dysfunction in adult adrenal glands.

Metabolomics, network pharmacology, and microbiome analyses uncover the mechanisms of the Chinese herbal formula for the improvement of meat quality in spent hens

BACKGROUND

Meat originating from the spent hen is an important source of poultry meat production; however, multiple factors cause the decline in the meat quality of spent hens. Chinese herbs have been widely used as medicine for a long time to prevent diseases and as nutrient supplements to improve the product quality. This experiment explored the effects of adding 1.0% Chinese herbal formula (CHF, including 0.30% Leonurus japonicus Houtt., 0.20% Salvia miltiorrhiza Bge., 0.25% Ligustrum lucidum Ait., and 0.25% Taraxacum mongolicum Hand.-Mazz.) for 120 d to the spent hens' diet through metabolomics, network pharmacology, and microbiome strategies.

RESULTS

The results indicated that CHF supplementation improved the meat quality by reducing drip loss (P < 0.05), b* value (P = 0.058), and shear force (P = 0.099) and increasing cooked meat percentage (P = 0.054) and dry matter (P < 0.05) of breast muscle. The addition of CHF improved the nutritional value of breast muscle by increasing (P < 0.05) the content of C18:2n-6, n-6/n-3 polyunsaturated fatty acids (PUFA), total PUFA, PUFA-to-saturated fatty acids (SFA) ratio, and hypocholesterolemic-to-hypercholesterolemic ratio, and tending to increase serine content (P = 0.069). The targeted metabolomics analysis revealed that the biosynthesis of SFA, linoleic acid metabolism, fatty acid degradation, fatty acid elongation, and fatty acid biosynthesis pathways were enriched by CHF supplementation. Furthermore, the network pharmacology analysis indicated that CHF was closely associated with oxidative stress and lipid metabolism. The CHF supplementation increased the glutathione peroxidase level (P < 0.05) and upregulated gene expression related to the Nrf2 pathway (including HO-1, P < 0.05; Nrf2, P = 0.098; CAT, P = 0.060; GPX1, P = 0.063; and SOD2, P = 0.052) and lipid metabolism (including PPARγ, P < 0.05; SREBP1, P = 0.059; and CPT1A, P = 0.058). Additionally, CHF supplementation increased Firmicutes and decreased Bacteroidetes, Spirochaetes, and Synergistetes abundances (P < 0.05), which may contribute to better meat quality.

CONCLUSIONS

Our results suggest that CHF supplementation improved the quality and nutritional value of meat, which will provide a theoretical basis for the utilization of CHF as a feed additive in spent hens' diets.

Rapid separation of bile acid isomers via ion mobility mass spectrometry by complexing with spiramycin

Bile acid (BA) is one of the main active components of bile and has multiple isomers, the structure or content of its isomers often changes due to diseases and other health problems; thus, the accurate detection of BA isomers is very important. In this study, two groups of BA isomers of glycine-conjugated BAs and taurine-conjugated BAs were simultaneously separated and quantitatively analyzed by ion mobility mass spectrometry (IM-MS). Especially, baseline mobility separation between the isomers was achieved by the formation of binary complexes via simple interaction with spiramycin (SPM), for which a separation resolution (Rp-p) of 1.96 was reached. Moreover, BA isomers were quantitatively analyzed, and the limit of detection (LOD) of absolute quantification for TCDCA/TUDCA and GUDCA/GCDCA/GHDCA was 0.514 and 0.611 ng∙mL-1, respectively; the LODs for molar ratio ranges of relative quantification for TCDCA/TUDCA, GUDCA/GHDCA, and GCDCA/GHDCA were 1:18-30:1, 1:18-21:1, and 1:19-21:1, respectively. Additionally, BA isomers analyzed in pig bile powder and bear bile powder were measured, which were in good consistency with those labeled, revealing the differences in BA composition and content between the two powders. Finally, BA detection and recovery analyses were performed on serum samples, with a recovery rate of ≥73.69%, RSD of ≤6.8%, and SR (standard deviation of recoveries, the degree of difference between measured values and average recovery) of ≤1.27. Due to the simple, rapid, and lack of need for complex sample preparation and chromatographic separation, the proposed method can be an effective method for BA detection in practical samples.

Probiotic Lactobacillus rhamnosus GG improves insulin sensitivity and offspring survival via modulation of gut microbiota and serum metabolite in a sow model

BACKGROUND

Sows commonly experience insulin resistance in late gestation and lactation, causing lower feed intake and milk production, which can lead to higher mortality rates in newborn piglets. The probiotic Lactobacillus rhamnosus GG (LGG) is known to improve insulin resistance. However, whether supplementing LGG can improve insulin sensitivity in sows and enhance lactation performance, particularly the early survival of offspring remains unclear. Hence, we explored the effects and mechanisms of supplementing LGG during late gestation and lactation on sow insulin sensitivity, lactation performance, and offspring survival. In total, 20 sows were randomly allocated to an LGG (n = 10) and control group (n = 10).

RESULTS

In sows, LGG supplementation significantly improved insulin sensitivity during late gestation and lactation, increased feed intake, milk production and colostrum lactose levels in early lactation, and enhanced newborn piglet survival. Moreover, LGG treatment significantly reshaped the gut microbiota in sows, notably increasing microbiota diversity and enriching the relative abundance of insulin sensitivity-associated probiotics such as Lactobacillus, Bifidobacterium, and Bacteroides. Serum metabolite and amino acid profiling in late-gestation sows also revealed decreased branched-chain amino acid and kynurenine serum levels following LGG supplementation. Further analyses highlighted a correlation between mitigated insulin resistance in late pregnancy and lactation by LGG and gut microbiota reshaping and changes in serum amino acid metabolism. Furthermore, maternal LGG enhanced immunity in newborn piglets, reduced inflammation, and facilitated the establishment of a gut microbiota.

CONCLUSIONS

We provide the first evidence that LGG mitigates insulin resistance in sows and enhances offspring survival by modulating the gut microbiota and amino acid metabolism.

Metabolic and fecal microbial changes in adult fetal growth restricted mice

BACKGROUND

Fetal growth restriction (FGR) increases risk for development of obesity and type 2 diabetes. Using a mouse model of FGR, we tested whether metabolic outcomes were exacerbated by high-fat diet challenge or associated with fecal microbial taxa.

METHODS

FGR was induced by maternal calorie restriction from gestation day 9 to 19. Control and FGR offspring were weaned to control (CON) or 45% fat diet (HFD). At age 16 weeks, offspring underwent intraperitoneal glucose tolerance testing, quantitative MRI body composition assessment, and energy balance studies. Total microbial DNA was used for amplification of the V4 variable region of the 16 S rRNA gene. Multivariable associations between groups and genera abundance were assessed using MaAsLin2.

RESULTS

Adult male FGR mice fed HFD gained weight faster and had impaired glucose tolerance compared to control HFD males, without differences among females. Irrespective of weaning diet, adult FGR males had depletion of Akkermansia, a mucin-residing genus known to be associated with weight gain and glucose handling. FGR females had diminished Bifidobacterium. Metabolic changes in FGR offspring were associated with persistent gut microbial changes.

CONCLUSION

FGR results in persistent gut microbial dysbiosis that may be a therapeutic target to improve metabolic outcomes.

IMPACT

Fetal growth restriction increases risk for metabolic syndrome later in life, especially if followed by rapid postnatal weight gain. We report that a high fat diet impacts weight and glucose handling in a mouse model of fetal growth restriction in a sexually dimorphic manner. Adult growth-restricted offspring had persistent changes in fecal microbial taxa known to be associated with weight, glucose homeostasis, and bile acid metabolism, particularly Akkermansia, Bilophilia and Bifidobacteria. The gut microbiome may represent a therapeutic target to improve long-term metabolic outcomes related to fetal growth restriction.

Gut microbiota and metabolite variations in a migraine mouse model

Migraine is a prevalent clinical disorder characterized by recurrent unilateral throbbing headache episodes accompanied by symptoms such as nausea, vomiting, photophobia, and phonophobia. Despite its common occurrence, the diagnosis, pathophysiology, and treatment of migraine remain controversial. Extensive research has implicated the gut microbiota in various central nervous system disorders, including anxiety disorders, depression, and Parkinson's disease. Some studies have also suggested that migraine may stem from disruptions to neurohormones and metabolism. This study aimed to investigate the disparities in gut microbiota and metabolites between migraine mice model and normal mice to shed light on the underlying mechanisms and potential therapeutic approaches. Distinct differences in gut microbial composition were observed between the migraine mouse model and normal mouse, indicating a potential correlation between these variations and the pathogenesis of migraine. This study provides evidence of differences in gut microbiota composition and metabolites between a migraine mouse model and normal mice, which showed that Akkermansiaceae constituted the most abundant taxon in the sham injection mouse group, while Lachnospiraceae constituted the most prevalent group in the migraine mouse model group. The associations between the abundances of Akkermansia muciniphila and Lachnospiraceae bacteria and metabolites suggested their potential roles in the pathogenesis of migraine. The altered abundance of Lachnospiraceae observed in migraine-afflicted mice and its correlations with changes in metabolites suggest that it may affect the host's health. Thus, probiotic therapy emerges as a possible treatment for migraine. Moreover, significant disparities in gut metabolites were observed between the migraine mouse model and normal mice. These alterations encompass multiple metabolic pathways, suggesting that metabolic disturbances may also contribute to the development of migraines.

Bile Acid Metabolic Profiles and Their Correlation with Intestinal Epithelial Cell Proliferation and Barrier Integrity in Suckling Piglets

Bile acids (BAs) are crucial for maintaining intestinal epithelial homeostasis. However, the metabolic changes in BAs and the communication between intestinal epithelial cells (IECs) in infants after birth remain unclear. This study aims to elucidate the BA profiles of newborn piglets (NPs) and suckling piglets (SPs), and to investigate their regulatory effects on IEC proliferation and barrier integrity, as well as the potential underlying mechanisms. In this study, compared with NPs, there were significant increases in serum triglycerides, total cholesterol, glucose, and albumin levels for SPs. The total serum BA content in SPs exhibited an obvious increase. Moreover, the expression of BA synthase cytochrome P450 27A1 (CYP27A1) was increased, and the ileal BA receptor Takeda G-coupled protein receptor 5 (TGR5) and proliferation marker Ki-67 were upregulated and showed a strong positive correlation through a Spearman correlation analysis, whereas the expression of farnesoid X receptor (FXR) and occludin was markedly downregulated in SPs and also revealed a strong positive correlation. These findings indicate that the increased synthesis and metabolism of BAs may upregulate TGR5 and downregulate FXR to promote IEC proliferation and influence barrier function; this offers a fresh perspective and evidence for the role of BAs and BA receptors in regulating intestinal development in neonatal pigs.