Animal microbiome最新文献

Background: Dogs-whether pets, rural, or stray-exhibit distinct living styles that influence their fecal microbiota and resistomes, yet these dynamics remain underexplored. This study aimed to analyze and compare the fecal microbiota and resistomes of three groups of dogs (37 pets, 20 rural, and 25 stray dogs) in Shanghai, China.

Results: Metagenomic analysis revealed substantial differences in fecal microbial composition and metabolic activities among the dog groups. Pet dogs displayed the lowest microbial diversity. Using Shapley Additive Explanations (SHAP), an interpretable machine learning approach, Ligilactobacillus emerged as the most diverse genus, with significantly higher SHAP values in stray dogs, suggesting enhanced adaptability to more variable and less controlled environments. Across all samples, 587 antibiotic resistance genes (ARGs) were identified, conferring resistance to 14 antibiotic classes. A striking observation was the detection of mcr-1 in one pet dog, indicating a potential public health risk. The floR gene was identified as a key differentiator in resistance profiles, particularly in pet and rural dogs, likely due to antibiotic exposure in their environments.

Conclusion: This study provides the first comprehensive assessment of fecal microbiota and resistome variations among dogs with different lifestyles, revealing a less resilient microbiome and heightened antimicrobial resistance in pet dogs, which could have public health implications.

The composition and function of animal gut microbiota are shaped by various factors, among which diet is one of the major factors. Diet is affected by seasonal shifts and geographical differences, which in turn impact the host's nutritional levels. To adapt to these environmental changes, the gut microbiome often produces matching responses. Understanding the relationships among the environment, diet, host and the gut microbiome is helpful for exploring the environmental adaptation of wildlife. Here, we chose wild sika deer (Cervus nippon), which is composed natural allopatric populations, to explore how the environment shapes the gut microbiome and affects the relationship between microbiota composition and function and the mutual adaptation of the seasonal living environment to seasonal dietary changes. To this purpose we used DNA metabarcoding, 16S RNA gene amplification sequencing, metagenomic shotgun sequencing and nutritional analyses to comprehensively examine the relationships among the forage plant, nutrient status and host gut microbiome. Our analyses showed spatiotemporal differences in diet between the Tiebu and Hunchun regions, which ultimately led to varying intakes of protein, cellulose, and soluble sugar. The microbiome composition and function showed unique characteristics in each group, and significant differences were detected at the gene level for the protein absorption and metabolism pathway, the carbohydrate metabolic absorption pathway, and cellulase enzyme function, which are related to nutrition. We also found differences in the pathogenic bacteria and resistance mechanisms genes of the gut microbiota in different groups. Our results showed that the gut microbiome of allopatric populations adapts to changes in food composition and nutrition in different seasons and areas to help the host cope with spatiotemporal changes in the living environment. At the same time, varying levels of human activity can have potential health impacts on wild animals.

Background: In aquaculture, the secretions of cultured organisms contribute to the development of aquatic antibiotic resistance. However, the antibiotic-induced changes in fish feces remain poorly understood. This study aimed to assess the short-term dynamics of fecal microbiome and antibiotic resistance in juvenile rainbow trout (Oncorhynchus mykiss) upon antibiotic treatment and withdrawal period.

Methods: Fish were orally administered diets supplemented with oxytetracycline (OTC) or sulfadiazine/trimethoprim (SDZ/TMP) for 10 consecutive days, followed by a 25-day withdrawal period. Fecal samples were collected before antibiotic treatment (day 0), and at 1, 3, 7, and 10 days post antibiotic administration (dpa), as well as 1, 3, 7, 14, and 25 days post antibiotic cessation (dpc). The fecal microbiome community was profiled using both culture-dependent and -independent methods. The relative abundance of antibiotic resistance genes (ARGs) and the class 1 integron-integrase gene (intI1) in the feces were quantified using real-time PCR.

Results: Antibiotic treatment disrupted the fecal microbial communities, and this alteration persisted even after antibiotic cessation. Moreover, OTC treatment increased the relative abundance of tet genes, while sul and dfr genes increased in the SDZ/TMP-treated group. Notably, Flavobacterium, Pseudomonas, and Streptococcus exhibited a significant correlation with the abundance of ARGs, suggesting their potential role as carriers for ARGs.

Conclusion: This study demonstrates the antibiotic-induced changes in the fecal microbiome and the increase of ARGs in rainbow trout feces. These findings provide novel insights into the dynamics of microbiome recovery post-antibiotic cessation and suggest that fish feces provide a non-invasive approach to predict changes in the fish gut microbiome and resistome.

Heterogeneity of the rearing environment in farmed animals can improve welfare and stocking success by enhancing natural behaviours, reducing stress, and decreasing pathogen occurrence. Although microbial diversity is often associated with well-being, their direct and indirect effects on health of farmed animals remain underexplored. We examined the impact of structural heterogeneity of aquaculture tanks on microbial communities in tank biofilm and fish gut microbiome. Enrichment (stones and shelters) significantly promoted microbial diversity and community homogeneity in tank biofilm. However, diversity of gut microbiome did not depend on rearing treatment or microbial composition of the environment. Fish in enriched tanks exhibited greater compositional variation in gut microbiome than those in standard tanks. Tanks without enrichments had higher occurrence of potentially pathogenic bacterial families (Corynebacteriaceae and Staphylococcaceae), while enriched tanks had more beneficial gut microbes (Lactobacillus). Microbial diversity in tank biofilm was negatively associated with fish mortality during a natural epidemic of Flavobacterium columnare, suggesting a protective effect of diverse microbial communities. These findings support environmental enrichment in mitigating disease outbreaks through enhanced microbial diversity, providing important implications for disease control and sustainable health management in aquaculture.

Background: Antibiotic use has undesirable side-effects on the host, including perturbations of gut microbiota, immunity, and health. Mammalian studies have demonstrated that concomitant/post antibiotic use of pro-, pre-, and synbiotics could re-establish gut microbiota and prevent detrimental host effects. However, studies evaluating similar effects in fish are scanty. This study evaluated the effects of dietary supplementation with a synbiotic mixture on the post-smolt Atlantic salmon gut microbiota, growth performance, and health during antibiotic treatment and subsequent recovery. Fish in five tanks each were fed either a commercial control diet or a synbiotic diet containing Pediococcus acidilactici and fructo-oligosaccharides, for 6 weeks (S1). Then, fish in three tanks per treatment were fed with medicated diets, containing 3500 ppm florfenicol coated onto the control or synbiotic diets, for 2 weeks (S2) and refed with the respective nonmedicated diets for another 3 (S3) and 5 (S4) weeks of recovery period. The fish not subjected to medication were fed the control or synbiotic diets throughout the experimental period. Samples were collected at S1-S4 from both the nonmedicated and medicated fish.

Results: Florfenicol decreased the feed intake in control group. It reduced the growth rate in both control and synbiotic groups with lesser reduction in synbiotic group. Florfenicol did not significantly affect observed taxa and Shannon indexes. Bacterial composition before and after medication clustered distinctly in control and clustered together in synbiotic groups. Lactobacillus dominated in control while Lactobacillus and Pediococcus dominated in synbiotic group during medication and recovery. Florfenicol did not significantly influence the immune or stress response marker gene expressions, though the expression patterns differed between diet groups. Florfenicol did not cause inflammation in the distal intestine or change hepatosomatic index.

Conclusions: This study highlighted the negative impact of a two-week florfenicol treatment on feed intake and growth performance in Atlantic salmon, with moderate effects on gut microbiota and gene expression. Concomitant use of a synbiotic diet helped to maintain the gut microbial composition and influenced the performance positively and immune gene expressions differently during medication. This study indicates the importance of nutritional interventions through synbiotic supplementation as a possible strategy for managing Atlantic salmon during antibiotic treatment.

Background: Enterotoxigenic Escherichia coli (E. coli) is one of the most prevalent causes of diarrhea in young animals. Postbiotics derived from yeast have the potential to positively influence the mucosal microbiota in the jejunum, therefore it was hypothesized that Saccharomyces yeast postbiotics could enhance the microbiota and mucosal immune response in the jejunum, mitigating the effects of infection with enterotoxigenic E. coli. The purpose of this study was to investigate the effects of a Saccharomyces yeast postbiotic on the mucosal microbiota and mucosal immune response in the jejunum of newly weaned pigs challenged with F18⁺ E. coli.

Results: Thirty-six individually housed nursery pigs were allotted into three treatments utilizing a randomized complete block design; negative control (NC: basal diet, no challenge), positive control (PC: basal diet, challenge), and SYP (basal diet + Saccharomyces yeast postbiotics at 175 g/ton, challenge). On d 7, PC and SYP were orally inoculated with F18⁺ E. coli, whereas NC received saline. On d 28, pigs were euthanized for sampling of the jejunum to analyze the mucosal microbiota, oxidative stress, immune status, and intestinal morphology. The PC reduced (P < 0.05) growth performance compared to NC. The SYP improved (P < 0.05) fecal score from d 7-18 when compared with PC. SYP reduced (P < 0.05) protein carbonyl, reduced (P < 0.05) gene expression of Toll-like receptor 4, and increased (P < 0.05) gene expression of mammalian target of rapamycin, compared with PC.

Conclusions: Challenge with F18⁺ E. coli negatively impacted jejunal mucosa-associated microbiota and jejunal morphology, affecting growth performance. Saccharomyces yeast postbiotics could reduce the negative effects associated with F18⁺ E. coli infection.

Pork is currently a major part of Danish food export and is also a key dietary source of protein across the world. Industrial pork production, however, comes with high antibiotic usage in many countries, including Denmark. This has created consumer demand for meat Raised Without Antibiotics (RWA). Previous work has demonstrated that levels of antibiotic resistance genes (ARGs) are indeed increased in antibiotically treated animals, but also suggest that these ARGs are transferred to untreated pen-mates. In a Danish commercial farm, we studied four groups of physically separated pigs: one group of only antibiotic treated pigs (n = 20), one group of only untreated pigs (n = 30 total, n = 15 analysed), and one group combining treated (n = 15) and untreated pigs (n = 15). These groups were followed for 16 weeks during which all pigs were profiled for both their faecal microbiome (through 16 S rRNA gene sequencing) and resistome (by use of a high-throughput qPCR platform targeting 82 ARGs and their variants). We found that the resistome of treated pigs was substantially enriched in resistance genes compared to untreated pigs but, importantly, observed that untreated pigs co-reared with treated pigs had levels of resistance genes approaching their treated pen mates, suggesting that the treated enterotype is readily transferred to the untreated animal. From this, we conclude that mixing of treated and untreated pigs causes spill-over of antibiotic resistant bacteria and/or resistance genes from treated pigs when these are co-reared. To optimize RWA production, treated and untreated pigs should be physically separated to limit the proliferation of ARGs.

Background: The gut microbiota and derived metabolites play a key role in regulating host physiology. Diet is identified as a key regulatory factor of the microbiota composition and, potentially, of subsequent functionalities. Demonstrating the role of diet may be complex as most human studies are cross-sectional and dietary intervention is often accompanied by hygienic changes. The objective of the present study was to investigate the impact of an industrial diet on the modulation of the microbiota and targeted functionalities using a canine "natural" model.

Results: We carried out a controlled dietary trial in a cohort of Tunisian semi-stray dogs. We made a transition from a natural diet to an industrial kibble diet and monitored the composition of the fecal microbiota, the concentration of short-chain fatty acids (SCFA) and bile acids (BAs), and protease activities. We demonstrated that dietary change significantly decreased fecal primary bile acids levels and protease activities. Interestingly, correlation analyses demonstrated that variation of specific microbial genera were associated with modulated physiological parameters.

Conclusions: Our study reveals that an industrial diet induces beneficial changes in microbial composition and functions characterised by increased diversity, synthesis of SCFA and secondary bile acids production, stressing the key role of the diet-microbiota-dog crosstalk.

Background: Specific sources of dietary fibres in sow gestation and lactation diets, such as inulin or wheat bran, have been shown to affect both the sow and its litter health by modulating the piglet's intestinal microbial population and composition. However, only a few studies have reported the effects of some specific fractions of the cell wall of the plants in the sow's lactation diet. Therefore, this study investigates the effect of increasing the level of HCs in a sow's lactation diet on the nutrient apparent total tract digestibility (ATTD), the faecal volatile fatty acid (VFA) profile, the microbiota of the sow and the microbiota and the performances of slow-growing (SG) and fast-growing (FG) piglets.

Results: Increasing HCs level increased (P < 0.05) the proportions of butyrate and valerate on day 3, and the ATTD of acid detergent fibres (ADF), neutral detergent fibres (NDF), and gross energy and decreased (P < 0.05) the proportion of propionate on day 17, and the ATTD of crude protein. The beta diversity was affected (r² = 0.11; P = 0.02) by the maternal dietary treatments with 11 common genera differing (P < 0.05) in the sow's faecal microbiota, and five in the piglet's microbiota. Regardless of the maternal dietary treatment, SG piglets had a lower (P < 0.05) proportion of isobutyrate and isovalerate, a lower (P < 0.05) abundance of Lachnospiraceae_XPB1014_group, Enterococcus, and Succinovibrio genera, and a greater (P < 0.05) abundance of Olsenella than FG piglets.

Conclusions: Increased HCs level in a sow's lactation diet affects the ATTD of nutrients, the faecal VFA and microbiota profiles of the sows with limited effects on SG and FG piglets' faecal microbiota and no effects on the performance or VFA profile of these piglets.

Grey mullet (Mugil cephalus) aquaculture is economically vital due to the high value of its roe. However, it faces significant risks from disease outbreaks, particularly from Nocardia seriolae. Current reliance on antibiotics has drawbacks, highlighting the potential of probiotics as a promising alternative. Despite this, no studies have focused on the effects and mechanisms of probiotics in disease prevention and treatment in grey mullet. This study, therefore, investigates the efficacy of probiotics in enhancing disease resistance and promoting growth in grey mullet. Three strains of probiotics, Lacticaseibacillus rhamnosus FS3051, Limosilactobacillus reuteri FS3052, and Bacillus subtilis natto NTU-18, were selected to evaluate their anti-N. seriolae activity and hydrolytic enzyme secretion in vitro. Then, 144 grey mullet were randomly divided into four groups: control, L. rhamnosus FS3051, L. reuteri FS3052, and B. subtilis natto NTU-18. After being fed the corresponding diet for 28 days, fish were measured for immune gene expression and short-term growth followed by challenge of N. seriolae. Survival rates were recorded for 35 days post challenge. Additionally, the gut microbiota of the control and probiotic groups with effects on both growth and protection against N. seriolae were analyzed to investigate the potential role of gut microbiota. Results demonstrated that L. rhamnosus FS3051 and L. reuteri FS3052 inhibited N. seriolae, while B. subtilis natto NTU-18 did not inhibited N. seriolae. Probiotics also had the ability to secrete hydrolytic enzymes. Probiotic-fed grey mullet showed significant improvements in weight gain ratio, feed efficiency, and specific growth rate, particularly in the B. subtilis natto NTU-18 group. Immune gene expression was enhanced by probiotics, especially L. rhamnosus, FS3051, which induced IL-8, IL-1β, TNF-α, IFN-γ, and MHCI. Survival rates post-N. seriolae challenge improved significantly for L. rhamnosus FS3051-fed fish. L. rhamnosus FS3051 also altered the gut microbiota, enriching beneficial genera like Lactobacillus, which correlated positively with immune responses and growth, while reducing Mycoplasma and Rhodobacter, which were negatively correlated with immune responses. This study underscores the potential of probiotics in enhancing disease resistance and growth via regulating gut microbiota in grey mullet.