BackgroundNecrotic enteritis caused by Clostridium perfringens infection leads to serious economic losses in the global poultry production. In the present study, we investigated the protective effects of essential oils (EO, which contained 25 % thymol and 25 % carvacrol as active components) supplementation on growth performance, gut lesions, intestinal morphology, and immune responses of the broiler chickens infected with C. perfringens. A total of 448 1-day-old male broiler chicks were allocated into eight treatment groups following a 4 × 2 factorial arrangement with four dietary EO dosages (0, 60, 120, or 240 mg/kg) and two infection status (with or without C. perfringens challenge from d 14 to 20).ResultsThe challenge did not impair the growth performance of birds, but induced gut lesions and increased crypt depth in the ileum (P ≤ 0.05). It also down-regulated the claudin-1 and occludin mRNA expression (P ≤ 0.05), up-regulated the mRNA expression of interleukin-1β (P ≤ 0.05), tended to increase the toll-like receptor (TLR) 2 mRNA expression (P < 0.10) in the ileum, and enhanced the mucosal secretory IgA production (P ≤ 0.05). In the challenged birds, dietary EO supplementation linearly alleviated the gut lesions and improved the ratio of villus height to crypt depth (P ≤ 0.05), and the supplementation of 120 and 240 mg/kg EO increased the serum antibody titers against Newcastle disease virus (P ≤ 0.05). Regardless of challenge, the EO supplementation showed a tendency to linearly elevate the feed conversion efficiency between 14 and 28 d of age as well as the occludin mRNA expression (P < 0.10), and linearly inhibited the mRNA expression of TLR2 and tumor necrotic factor-α in the ileum (P ≤ 0.05).ConclusionsThe dietary supplementation of EO could alleviate the intestinal injury by improving intestinal integrity and modulating immune responses in the C. perfringens-challenged broiler chickens.

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To investigate the effects of Clostridium butyricum and Enterococcus faecium on the growth performance, lipid metabolism, and cecal microbiota of broilers, 264 one-day-old male Ross 308 broiler chicks were randomly allocated into four treatments with six replicates in a 2 × 2 factorial arrangement and fed four diets with two levels of C. butyricum (0 or 1 × 10⁹ cfu/kg) and two levels of E. faecium (0 or 2 × 10⁹ cfu/kg) for 42 days. There was no significant interaction between C. butyricum and E. faecium on the growth performance, lipid metabolism, and cecal microbiota of broilers. However, broilers supplemented with E. faecium had lower (P = 0.022) serum leptin level at day 21 and higher (P < 0.001) fatty acid synthase (FAS), malic enzyme (ME), and acetyl-CoA carboxylase (ACC) mRNA levels in the liver at day 42. Supplementation of C. butyricum improved (P < 0.05) the average daily feed intake and average daily gain, increased (P = 0.016) the serum insulin level at 21 days of age, enhanced (P < 0.05) the content of intramuscular fat, activities of FAS in the liver and lipoprotein lipase (LPL) in the breast muscle, mRNA expression of FAS, ME, and ACC in the liver and LPL in the breast muscle at 42 days of age, but reduced (P = 0.030) cecal Bacteroidetes relative abundance at 21 days of age. The results of this study indicate that the increased intramuscular fat content of broilers fed C. butyricum as observed may be the result of enhanced lipogenesis.

Chronic urticaria (CU) is defined as the continuous or intermittent presence of urticaria for a period exceeding 6 weeks and sometimes occurring with angioedema. Between 66 and 93% of patients with CU have chronic spontaneous urticaria (CSU), the precise pathogenesis of which is largely unknown. The aim of this study was to determine the relationship between gut microbiota and serum metabolites and the possible pathogenesis underlying CSU. We collected feces and blood samples from CSU patients and healthy controls and the relationship between gut microbiota and serum metabolites was assessed using 16S rRNA gene sequencing and untargeted metabolomic analyses. The CSU group exhibited decreased alpha diversity of the microbial population compared to the control group. The abundance of unidentified Enterobacteriaceae was increased, while the abundance of Bacteroides, Faecalibacterium, Bifidobacterium, and unidentified Ruminococcaceae was significantly reduced in CSU patients. The serum metabolome analysis revealed altered levels of docosahexaenoic acid, arachidonic acid, glutamate, and succinic acid, suggesting changes in unsaturated fatty acids and the butanoate metabolism pathway. The combined serum metabolomics and gut microbiome datasets were correlated; specifically, docosahexaenoic acid, and arachidonic acid were positively correlated with Bacteroides. We speculate that alterations in gut microbes and metabolites may contribute to exacerbated inflammatory responses and dysregulated immune function with or without regulatory T cell dependence in the pathogenesis of CSU.

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