Modified Montmorillonite Improved Growth Performance of Broilers by Modulating Intestinal Microbiota and Enhancing Intestinal Barriers, Anti-Inflammatory Response, and Antioxidative Capacity

Zinc lactate alleviates oxidative stress by modulating crosstalk between constitutive androstane receptor signaling pathway and gut microbiota profile in weaned piglets

This study aimed to determine the regulatory mechanism of dietary zinc lactate (ZL) supplementation on intestinal oxidative stress damage in a paraquat (PQ)-induced piglet model. Twenty-eight piglets (mean body weight 9.51 ± 0.23 kg) weaned at 28 d of age were randomly divided into control, ZL, PQ, and ZL + PQ groups (n = 7 in each group). The ZL-supplemented diet had little effect on growth performance under normal physiological conditions. However, under PQ challenge, ZL supplementation significantly improved average daily gain (P < 0.05) and reduced the frequency of diarrhea. ZL improved intestinal morphology and ultrastructure by significantly increasing the expression level of the jejunal tight junction protein, zonula occludens-1 (ZO-1) (P < 0.05), and intestinal zinc transport and absorption in PQ-induced piglets, which reduced intestinal permeability. ZL supplementation also enhanced the expression of antioxidant and anti-inflammatory factor-related genes and decreased inflammatory cytokine expression and secretion in PQ-induced piglets. Furthermore, ZL treatment significantly inhibited the activation of constitutive androstane receptor (CAR) signaling (P < 0.01) in PQ-induced piglets and altered the structure of the gut microbiota, especially by significantly increasing the abundance of beneficial gut microbes, including UCG_002, Ruminococcus, Rikenellaceae_RC9_gut_group, Christensenellaceae_R_7_group, Treponema, unclassified_Christensenellaceae, and unclassified_Erysipelotrichaceae (P < 0.05). These data reveal that pre-administration of ZL to piglets can suppress intestinal oxidative stress by improving antioxidant and anti-inflammatory capacity and regulating the crosstalk between CAR signaling and gut microbiota.

Characterizing core microbiota and regulatory functions of the pig gut microbiome

Domestic pigs (Sus scrofa) are the leading terrestrial animals used for meat production. The gut microbiota significantly affect host nutrition, metabolism, and immunity. Hence, characterization of the gut microbial structure and function will improve our understanding of gut microbial resources and the mechanisms underlying host-microbe interactions. Here, we investigated the gut microbiomes of seven pig breeds using metagenomics and 16S rRNA gene amplicon sequencing. We established an expanded gut microbial reference catalog comprising 17 020 160 genes and identified 4910 metagenome-assembled genomes. We also analyzed the gut resistome to provide an overview of the profiles of the antimicrobial resistance genes in pigs. By analyzing the relative abundances of microbes, we identified three core-predominant gut microbes (Phascolarctobacterium succinatutens, Prevotella copri, and Oscillibacter valericigenes) in pigs used in this study. Oral administration of the three core-predominant gut microbes significantly increased the organ indexes (including the heart, spleen, and thymus), but decreased the gastrointestinal lengths in germ-free mice. The three core microbes significantly enhanced intestinal epithelial barrier function and altered the intestinal mucosal morphology, as was evident from the increase in crypt depths in the duodenum and ileum. Furthermore, the three core microbes significantly affected several metabolic pathways (such as "steroid hormone biosynthesis," "primary bile acid biosynthesis," "phenylalanine, tyrosine and tryptophan biosynthesis," and "phenylalanine metabolism") in germ-free mice. These findings provide a panoramic view of the pig gut microbiome and insights into the functional contributions of the core-predominant gut microbes to the host.

Dietary novel alkaline protease from Bacillus licheniformis improves broiler meat nutritional value and modulates intestinal microbiota and metabolites

BACKGROUND

Different types of exogenous protease supplements have a positive impact on animal performance, but their effects on the nutritional value of meat and the gut microbial community of broilers have not been extensively studied. The objective of this investigation was to determine the impact of supplementation with a novel alkaline protease derived from Bacillus licheniformis (at doses of 0, 100, 200, 300, and 400 g/t) on the fatty acid and amino acid profiles, inosine monophosphate (IMP) levels, total volatile basic nitrogen (TVB-N) content found within the breast muscle, as well as the impact on the cecal microbiota and metabolites.

RESULTS

Supplementation with 200-400 g/t of the novel protease resulted in a significant elevation in the concentration of essential amino acids (P < 0.001), flavor amino acids (P < 0.001), and total protein (P = 0.013) within the breast muscle. Results derived from the 16S rRNA sequencing and untargeted metabolomics analysis of the cecal content revealed that the novel protease reshaped the cecal microbial and metabolite profiles. In particular, it led to increased relative abundances of Bacteroides, Lactobacillus, Alistipes, and Eubacterium, while simultaneously causing a reduction in the metabolites of D-lactic acid and malonic acid. Moreover, correlation analyses unveiled significant relationships between distinct microbes and metabolites with the contents of IMP, fatty acids, and amino acids in the broiler's breast muscle.

CONCLUSION

In summary, the novel protease regulated the intestinal microbial community and metabolism, thereby inducing changes in the compositions of fatty acids and amino acids profiles, as well as IMP levels in broiler meat. These alterations significantly contributed to the enhancement of the nutritional value and flavor of the meat.

Gut microbiota-derived 3-phenylpropionic acid promotes intestinal epithelial barrier function via AhR signaling

BACKGROUND

The intestinal epithelial barrier confers protection against the intestinal invasion by pathogens and exposure to food antigens and toxins. Growing studies have linked the gut microbiota to the intestinal epithelial barrier function. The mining of the gut microbes that facilitate the function of intestinal epithelial barrier is urgently needed.

RESULTS

Here, we studied a landscape of the gut microbiome of seven pig breeds using metagenomics and 16S rDNA gene amplicon sequencing. The results indicated an obvious difference in the gut microbiome between Congjiang miniature (CM) pigs (a native Chinese breed) and commercial Duroc × [Landrace × Yorkshire] (DLY) pigs. CM finishing pigs had stronger intestinal epithelial barrier function than the DLY finishing pigs. Fecal microbiota transplantation from CM and DLY finishing pigs to germ-free (GF) mice transferred the intestinal epithelial barrier characteristics. By comparing the gut microbiome of the recipient GF mice, we identified and validated Bacteroides fragilis as a microbial species that contributes to the intestinal epithelial barrier. B. fragilis-derived 3-phenylpropionic acid metabolite had an important function on the enhancement of intestinal epithelial barrier. Furthermore, 3-phenylpropionic acid facilitated the intestinal epithelial barrier by activating aryl hydrocarbon receptor (AhR) signaling.

CONCLUSIONS

These findings suggest that manipulation of B. fragilis and 3-phenylpropionic acid is a promising strategy for improving intestinal epithelial barrier. Video Abstract.

The molecular mechanisms of alpha-lipoic acid on ameliorating aflatoxin B1-induced liver toxicity and physiological dysfunction in northern snakehead (Channa argus)

This research aimed to evaluate the protective mechanism of alpha-lipoic acid (α-LA) on the food-borne aflatoxin B₁ (AFB₁) exposure-induced liver toxicity and physiological dysfunction in the northern snakehead (Channa argus). 480 fish (9.24±0.01 g) were randomly assigned to four treatment groups and fed with four experimental diets for 56 d including the control group (CON), AFB₁ group (200 ppb AFB₁), 600 α-LA group (600 ppm α-LA+200 ppb AFB₁), and 900 α-LA group (900 ppm α-LA+200 ppb AFB₁). The results revealed that 600 and 900 ppm α-LA attenuated AFB₁-induced growth inhibition and immunosuppression in northern snakehead. 600 ppm α-LA significantly decreased the serum aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and lactate dehydrogenase levels, and AFB₁ bioaccumulation, and attenuated the changes of hepatic histopathological and ultrastructure induced by AFB₁. Moreover, 600 and 900 ppm α-LA significantly up-regulated phase I metabolism genes (cytochrome P450-1a, 1b, and 3a) mRNA expression, inhibited the levels of malondialdehyde, 8‑hydroxy-2 deoxyguanosine and reactive oxygen species in the liver. Notably, 600 ppm α-LA significantly up-regulated the expression levels of nuclear factor E2 related factor 2 and its related downstream antioxidant molecules (heme oxygenase 1 and NAD(P)H: quinone oxidoreductase 1, etc.), increased the phase II detoxification enzyme-related molecules (glutathione-S-transferase and glutathione), antioxidant parameters (catalase and superoxide dismutase, etc.), and the expressions of Nrf2 and Ho-1 protein in the presence of AFB₁ exposure. Furthermore, 600 and 900 ppm α-LA significantly reduced the characteristic indices of AFB₁-induced endoplasmic reticulum stress (glucose-regulated protein 78 and inositol requiring enzyme 1, etc.), apoptosis (caspase-3 and cytochrome c, etc.) and inflammation (nuclear factor kappa B and tumor necrosis factor α, etc.), while increased the B-cell lymphoma-2 and inhibitor of κBα in the liver after being exposed to AFB₁. To summarize, the above results indicate that dietary α-LA could modulate the Nrf2 signaling pathway to ameliorate AFB₁-induced growth inhibition, liver toxicity, and physiological dysfunction in northern snakehead. Although the concentration of α-LA increased to 900 ppm from 600 ppm, the protective effects of the 900 ppm α-LA do not show an advantage over the 600 ppm α-LA, and even show inferiority in some respects. So that the recommended concentration of α-LA is 600 ppm. The present study provides the theoretical foundation for developing α-LA as the prevention and treatment of AFB₁-induced liver toxicity in aquatic animals.

Dietary supplementation with nano-composite of copper and carbon on growth performance, immunity, and antioxidant ability of yellow-feathered broilers

New feed additives as antibiotics substitutes are in urgent need in poultry production. Nano-composite of copper and carbon (NCCC), a novel copper donor with stronger antibacterial properties, is expected to promote broiler growth and diminish the negative effects of excess copper (Cu). Hence, the purpose of this study is to investigate the effects of NCCC on growth performance, immunity, and antioxidant ability of yellow-feathered broilers. A total of 240 1-d-old male yellow-feathered broilers were selected and randomly divided into four groups, with five replications per group and 12 birds per replication. The CON group was fed corn-soybean basal diets, while the N50, N100, and N200 groups were supplemented with 50, 100, and 200 mg/kg of NCCC in basal diets, respectively. The trial lasted for 63 d. The results demonstrated that only 200 mg/kg NCCC addition significantly increased the Cu content in serum and feces, and liver Cu content linearly increased with NCCC dosage increment (P < 0.05). Meanwhile, NCCC supplementation did not alter the growth performance, slaughter performance, immune organ indexes, and liver antioxidant ability of broilers (P > 0.05), but optimized the serum cytokine pattern by elevating the level of serum IL-10 (P < 0.05), and there were linear and quadratic increases in serum IL-4 with NCCC dosage increment (P < 0.05). On the whole, in spite of no impact on growth performance, 50 mg/kg NCCC was optimal to supplement in chicken diets due to the rise of serum IL-10 level and no extra environmental pollution and tissue residues.

Cannabidiol and Nano-Selenium Increase Microvascularization and Reduce Degenerative Changes in Superficial Breast Muscle in C. perfringens-Infected Chickens

Here, we demonstrated the potential of Cannabis-derived cannabidiol (CBD) and nanosized selenium (nano-Se) for the modulation of microvascularization and muscle fiber lesions in superficial breast muscle in C. perfringens-challenged chickens. The administration of CBD resulted in a decreased number of atrophic fibers (3.13 vs. 1.13/1.5 mm²) compared with the control, whereas nano-Se or both substances resulted in a decreased split fiber number (4.13 vs. 1.55/1.5 mm²) and in a lower number of necrotic myofibers (2.38 vs. 0.69/1.5 mm²) in breast muscle than the positive control. There was a significantly higher number of capillary vessels in chickens in the CBD+Nano-Se group than in the control and positive control groups (1.31 vs. 0.97 and 0.98, respectively). Feeding birds experimental diets lowered the activity of DNA damage repair enzymes, including 3,N4-ethenodeoxycytosine (by 39.6%), 1,N6-ethenodeoxyadenosine (by 37.5%), 8-oxo-guanine (by 36.2%), formamidopyrimidine (fapy)-DNA glycosylase (by 56.2%) and human alkyl adenine DNA glycosylase (by 40.2%) in the ileal mucosa, but it did not compromise the blood mitochondrial oxygen consumption rate (-2.67 OD/min on average). These findings indicate a potential link between gut mucosa condition and histopathological changes in superficial pectoral muscle under induced inflammation and show the ameliorative effect of CBD and nano-Se in this cross-talk due to their protection from mucosal DNA damage.