Animal microbiome最新文献

Background: Amidst the current biodiversity crisis, amphibians are particularly endangered by the emergence of infectious diseases. The skin disease chytridiomycosis is caused by the fungi Batrachochytrium dendrobatidis (Bd) and B. salamandrivorans (Bsal), which may interact with bacterial symbionts present on the amphibian epidermis. Extensive research has explored the interactions between the amphibian microbiota and Bd; yet, little is known about its interactions with Bsal. In this paper, we used the ribbed newt (Pleurodeles waltl), a model species displaying pronounced among-individual variation in response to Bsal, to (1) determine whether susceptibility to Bsal and individual microbiota vary between source groups; (2) test whether susceptibility to Bsal can be predicted from skin microbiota before exposure and (3) quantify microbiota volatility over time to determine whether Bsal infection intensity and chytridiomycosis severity correlate with the magnitude of shifts in bacterial communities caused by Bsal exposure.

Results: Our results demonstrate that newts of different origin harbor distinct microbiota even under uniform rearing conditions. We show that Bsal infection intensity and disease severity cannot be predicted from the diversity, structure, or composition of the skin microbiota of P. waltl. Instead, a strong relation between newts' source group and their response to Bsal suggests that other factors might underpin among-individual variation in Bsal susceptibility in this species. Moreover, our results indicate that the intensity of early Bsal infection and longer-term severity of chytridiomycosis do not correlate with the magnitude of microbiota change following Bsal exposure.

Conclusion: These results demonstrate a limited involvement of the microbiota in Bsal dynamics in P. waltl, suggesting that other mechanisms contribute to individual Bsal susceptibility. Further research on the relation between chytrid pathogens and their amphibian hosts will be instrumental to improve the conservation of the most endangered vertebrate class on earth.

Background: Ticks and fleas are important vectors and hosts for various emergent human pathogens, such as severe fever with thrombocytopenia syndrome virus, Crimean-Congo hemorrhagic fever virus, and tick-borne encephalitis virus. In the Qinghai-Tibet plateau of China, Marmota himalayana (marmots) serves as the primary reservoir for Yersinia pestis, primarily transmitted by fleas. Due to their wide distribution and large population, marmots serve as important host animals for ticks and fleas to survive and reproduce on the Qinghai-Tibet Plateau. However, the spectrum of RNA viruses found in ticks and fleas that feed on marmots is still not fully understood.

Methods: Ticks and fleas infesting marmots in the Qinghai-Tibet plateau, China, were collected in 2018. The RNA virome of pooled ticks and fleas were analyzed using a metatranscriptomics approach.

Results: A total of 30 RNA viruses were identified, with 11 viruses from ticks (Ixodes spp.) and 19 viruses from fleas (Oropsylla silantiewi), which were classified into 16 families, mainly Phasmaviridae (n = 4), Phenuiviridae (n = 4), and Iflaviridae (n = 3), Peribunyaviridae (n = 2). These viruses formed distinct clusters and shared less than 84% amino acid identity with their closest relatives, indicating that they belonged to novel members of their respective taxa and circulated among ticks and fleas for an extended period. Furthermore, six nearly identical viruses were shared between ticks and fleas, with 96.0 - 99.8% RNA-dependent RNA polymerase amino acid identity, but only 38.5 - 73.8% identity with known viruses, indicating potential interspecies transmission of viruses between ticks and fleas.

Conclusion: Overall, these findings highlight the diverse and abundant viruses that arthropods in the Qinghai-Tibet plateau can harbor, shedding light on the potential for cross-species transmission of viruses.

Bacillus-based probiotics are recognized as safe and effective alternatives to antibiotic growth promoters in poultry production. This study evaluated the effects of Bacillus subtilis PS-216 on broiler performance, gut health, and meat quality. Broilers received PS-216 spores continuously via drinking water (2 × 10⁹ spores/L; SW) or feed at low (2 × 10⁶ spores/kg; SF1) or high (2 × 10⁹ spores/kg; SF2) concentrations. Parameters were assessed at days 23 and 44, including growth performance, lymphatic organ weights, cecal microbiota composition, short-chain fatty acid (SCFA) profiles, and meat quality. All treatment groups demonstrated significant performance improvements compared to controls: body weight increased by 7.4-8.1% and feed conversion ratio improved by 3-11%. Thymus weight increased by approx. 22% across all groups, indicating immunomodulatory effects. Microbiota analysis revealed beneficial shifts including increased butyrate-producing taxa (Selenomonadales, Clostridium sensu stricto) and reduced stress-associated Anaeroplasma. The SF2 group showed enhanced cecal butyrate and acetate concentrations at day 23, with sustained butyrate elevation at day 44. Additionally, meat quality improvements were observed, particularly reduced electrical conductivity and improved breast meat color distribution in the SF2 group. Feed supplementation at 2 × 10⁹ spores/kg (SF2) provided the most comprehensive benefits across all measured parameters. These findings demonstrate that B. subtilis PS-216 enhances broiler performance through beneficial microbiota modulation and immune function improvement, supporting its potential as a sustainable alternative to antibiotic growth promoters in commercial poultry production.

This study investigated the effects of dietary supplementation of indigenous dietary fiber (DF) sources with different solubilities on the growth performance, intestinal health, and gut microbiota in meat geese. A total of 400 meat geese at 17-d-old were randomly divided into 4 treatments with 10 replicates per treatment and 10 geese per replicate in a 28-d trial. The dietary treatments included a corn-soybean meal basal diet (BD), and BD supplemented with wheat bran as high soluble DF source (HS), alfalfa meal as medium soluble DF source (MS), or bamboo meal as low soluble DF source (LS). The results showed that dietary supplements of DF sources improved the growth performance of geese by improving final body weight (P = 0.010) and average daily weight gain (P = 0.003), and decreasing feed to gain ratio (P < 0.001). Among the DF source supplemented groups, HS treatment decreased the feed to gain ratio compared to LS treatment (P = 0.015). Next, HS and MS treatments decreased the levels of uric acid (P = 0.022) and triglyceride (P = 0.003) compared to BD and LS groups, and HS treatment decreased the high-density lipoprotein cholesterol level (P = 0.032) in serum compared to BD, LS, and MS groups. Additionally, dietary supplement of DF sources, especially the HS treatment improved the immune function of ileum and cecum by decreasing the levels of interlukin-10 level (P < 0.001) and interlukin-1β (P < 0.001), and increasing the level of secretory immunoglobulin A (P < 0.05) compared to BD, LS, and MS groups. Also DF sources supplements, especially the MS and HS treatments enhanced the antioxidant capacity of ileum and cecum by increasing activities of CAT (P < 0.001), SOD (P = 0.006 in ileum, P < 0.001 in cecum), and T-AOC (P < 0.001), but decreasing the MDA level (P < 0.001) compared to BD and LS groups. Furthermore, the length of ileum in BD group was shorter than DF source supplemented groups. And HS group had the longest ileum length (P = 0.010) and villus height (P = 0.001), and the most goblet cell number (P = 0.013) among all groups. Finally, by comparing the gut microbiota composition among BD, LS, and HS groups, HS treatment induced the enrichments of Butyricicoccus and Gemmiger, which were correlated with the improvements in the growth performance, lipid and fatty acid metabolisms, and intestinal condition. In conclusion, this study indicated that dietary supplementation of DF source, especially the high soluble DF source modulated the gut microbiota, enhanced the growth performance, nutrient metabolism, and intestinal health of meat geese. These findings suggested that highly soluble fiber sources might be preferable to use in geese production.

Background: This study aimed to investigate the preventive effects of dietary linarin supplementation on Enterotoxigenic coli (ETEC) induced small intestinal barrier dysfunction in weaned piglets via gut microbiota modulation.

Results: Twenty-four weaned piglets were randomly assigned to four experimental groups. The four treatments were as follows: BD + NB (basal diet and orally administered nutrient broth), LN + NB (basal diet supplemented with 150 mg/kg linarin, and orally administered nutrient broth), BD + ETEC (basal diet and orally administered ETEC), LN + ETEC (basal diet supplemented with 150 mg/kg linarin, and orally administered ETEC). The results showed that linarin lowers the serum levels of diamine oxidase (DAO), endotoxin, and D-lactate (P < 0.05). Linarin significantly increased villus height and villus/crypt ratio (P < 0.01), while decreasing crypt depth in the duodenum. jejunum, and ileum (P < 0.05). Additionally, Linarin increased the number of goblet cells within villus-crypt units in the duodenum. jejunum, and ileum (P < 0.05). Linarin significantly enhanced intestinal barrier function, upregulated detoxification pathways, reduced epithelial apoptosis, and improved nutrient transporter expression in the small intestine." Linarin decreased the relative abundances of Actinobacillus, Romboutsia, Enterococcus, and Terrisporobacter, consequently modulating key metabolic pathways, including arginine and proline metabolism, steroid biosynthesis, and cysteine and methionine metabolism.

Conclusions: Dietary linarin supplementation mitigates ETEC-induced intestinal mucosal barrier dysfunction and enhances nutrient assimilation via targeted modulation of microbial communities and associated metabolic networks, thereby providing a new strategy for the prevention and treatment of ETEC diarrhea.