Differences between the intestinal microbial communities of healthy dogs from plateau and those of plateau dogs infected with Echinococcus.

OBJECTIVE: Cystic echinococcosis (CE) represents a profoundly perilous zoonotic disease. The advent of viral macrogenomics has facilitated the exploration of hitherto uncharted viral territories. In the scope of this investigation, our objective is to scrutinize disparities in the intestinal microbiotic ecosystems of canines dwelling in elevated terrains and those afflicted by Echinococcus infection, employing the tool of viral macrogenomics. METHODS: In this study, we collected a comprehensive total of 1,970 fecal samples from plateau dogs infected with Echinococcus, as well as healthy control plateau dogs from the Yushu and Guoluo regions in the highland terrain of China. These samples were subjected to viral macrogenomic analysis to investigate the viral community inhabiting the canine gastrointestinal tract. RESULTS: Our meticulous analysis led to the identification of 136 viral genomic sequences, encompassing eight distinct viral families. CONCLUSION: The outcomes of this study hold the potential to enhance our comprehension of the intricate interplay between hosts, parasites, and viral communities within the highland canine gut ecosystem. Through the examination of phage presence, it may aid in early detection or assessment of infection severity, providing valuable insights into Echinococcus infection and offering prospects for potential treatment strategies.

Gut microbiome-short-chain fatty acids interplay in the context of iron deficiency anaemia.

PURPOSE: Anaemia is a global health concern, with iron deficiency anaemia (IDA) causing approximately 50% of cases. Affecting mostly the elderly, pregnant and adult women and children, physiopathology of IDA in relation to the gut microbiome is poorly understood. Therefore, the objective of this study is to analyse, in an animal model, the effect of IDA on the gut microbiome along the gastrointestinal tract, as well as to relate intestinal dysbiosis to changes in microbial metabolites such as short chain fatty acids (SCFA). METHODS: IDA was experimentally induced through an iron deficient diet for a period of 40 days, with twenty weaned male Wistar rats being randomly divided into control or anaemic groups. Blood samples were collected to control haematological parameters, and so were faecal and intestinal content samples to study gut microbial communities and SCFA, using 16S rRNA sequencing and HPLC-UV respectively. RESULTS: An intestinal dysbiosis was observed as a consequence of IDA, especially towards the distal segments of the gastrointestinal tract and the colon. An increase in SCFA was also noticed during IDA, with the major difference appearing in the colon and correlating with changes in the composition of the gut microbiome. Clostridium_sensu_stricto_1 and Clostridium_sensu_stricto_4 showed the greatest correlation with variations in butyric and propionic concentrations in the colon of anaemic animals. CONCLUSIONS: Composition of intestinal microbial communities was affected by the generation of IDA. An enrichment in certain SCFA-producing genera and SCFA concentrations was found in the colon of anaemic animals, suggesting a trade-off mechanism against disease.

Estimating Postmortem Interval Using Intestinal Microbiota Diversity Based on 16S rRNA High-throughput Sequencing Technology. / 基于16S rRNAé«˜é€šé‡æµ‹åºæŠ€æœ¯çš„è‚ é“èŒç¾¤å¤šæ ·æ€§æŽ¨æ–­æ­»äº¡æ—¶é—´.

OBJECTIVES: To explore the correlation between intestinal microbiota and postmortem interval(PMI) in rats by using 16S rRNA high-throughput sequencing technology. METHODS: Rats were killed by anesthesia and placed at 16 ℃, and DNA was extracted in caecum at 14 time points of 0, 1, 2, 3, 5, 7, 9, 12, 15, 18, 21, 24, 27 and 30 d after death. The 16S rRNA high-throughput sequencing technology was used to detect intestinal microbiota in rat cecal contents, and the results were used to analyze the rat intestinal microbiota diversity and differences. RESULTS: The total number of intestinal microbial communities did not change significantly within 30 days after death, but the diversity showed an upward trend. A total of 119 bacterial communities were significantly changed at 13 time points after death. The models for PMI estimation were established by using partial least squares (PLS) regression at all time points, before 9 days and after 12 days, reaching an R2 of 0.795, 0.767 and 0.445, respectively; and the root mean square errors (RMSEs) were 6.57, 1.96 and 5.37 d, respectively. CONCLUSIONS: Using 16S rRNA high-throughput sequencing technology, the composition and structure of intestinal microbiota changed significantly within 30 d after death. In addition, the established PLS regression model suggested that the PMI was highly correlated with intestinal microbiota composition, showing a certain time series change.

L-Arginine and N-carbamoylglutamic acid supplementation enhance young rabbit growth and immunity by regulating intestinal microbial community.

OBJECTIVE: An experiment was conducted to determine the effects of L-arginine (L-Arg) and N-carbamoylglutamic acid (NCG) on the growth, metabolism, immunity and community of cecal bacterial flora of weanling and young rabbits. METHODS: Eighteen normal-grade male weanling Japanese White Rabbits (JWR) were selected and randomly divided into 6 groups with or without L-Arg and NCG supplementation. The whole feeding process was divided into weanling stage (Day 37 to 65) and young stage (Day 66 to 85). The effects of L-Arg and NCG on the growth, metabolism, immunity and development of the ileum and jejunum were compared via nutrient metabolism experiments and histological assessment. The different communities of cecal bacterial flora affected by L-Arg and NCG were assessed using high-throughput sequencing technology and bioinformatics analysis. RESULTS: The addition of L-Arg and NCG were able to enhance the growth of weanling and young rabbit by increasing the nitrogen metabolism, protein efficiency ratio, and biological value, as well as feed intake, daily weight gain. Both L-Arg and NCG were able to increase the concentration of IgA, IgM, and IgG. NCG was superior to L-Arg in promoting intestinal villus development by increasing villus height and V/C index, reducing the crypt depth. The effects of L-Arg and NCG on the cecal bacterial flora were mainly concentrated in different genera, including Parabacteroides, Roseburia, dgA-11_gut_group, Alistipes, Bacteroides, and Ruminococcaceae_UCG-005. These bacteria function mainly in amino acid transport and metabolism, energy production and conversion, lipid transport and metabolism, recombination and repair, cell cycle control, cell division, and cell motility. CONCLUSION: L-Arg and NCG have promotional ability on the growth and immunity of weanling and young Japanese White Rabbits, as well as their effects on the jejunum and ileum villi. L-Arg and NCG have different effects in the promotion of nutrient utilization, relieving inflammation and enhancing adaptability through regulating microbial community.

Screening of intestinal probiotics and the effects of feeding probiotics on the growth, immune, digestive enzyme activity and intestinal flora of Litopenaeus vannamei.

In this experiment, 426 strains were isolated from the intestinal tract of Litopenaeus vannamei, and 11 strains showed strong digestive enzyme production activity and antagonistic effect against common bacterial pathogens of shrimp. After hemolysis activity test and drug sensitivity test, 2 candidate probiotics with good bacteriostatic activity, strong enzyme production ability and relatively sensitive to antibiotics were screened out, and were identified by 16s rDNA molecular identification and Biolog-System as Enterobacter hominis (E3) and lactobacillus (L3). First, the biological characteristics of 2 candidate probiotics were studied. The optimum growth conditions of E3: temperature, 30 °C; pH, 8.0; NaCl, 2.5%; bovine bile salt, 0.15%; and the optimum growth conditions of L3: temperature, 40 °C; pH, 6.0; NaCl, 0.5%; bovine bile salt, 0.0015%. Secondly, a 28-day feeding experiment was conducted using probiotic concentration of 107 CFU g-1 to determine the changes of the activities of blood related immune enzymes (SOD, PPO, ACP, POD, CAT, LZM) and intestinal digestive enzymes (NP, AL, LPS) during the feeding process of shrimp, the results showed that during the course of feeding, the activities of immune enzyme and digestive enzyme of shrimp fed with probiotics showed an increasing trend, and the growth rate of body weight of shrimp was higher than that of control group. After feeding, the cumulative mortality of probiotics groups were significantly lower than that of the control group after WSSV infection. And the mid-gut of L. vannamei was observed by electron microscope, the results showed that the intestinal mucosa was tight and the epithelium cells showed an active secretory state in probiotics group. Finally, the intestinal microbial communities of shrimp were compared and analyzed by using Biolog-ECO method in the later period of feeding, the results showed: compared with the control group, the average color change rate of the experimental group fed with probiotics increased significantly, indicating that probiotics enhanced the intestinal microorganism activity; The ability of intestinal microorganism to utilize carbon source was significantly enhanced in the experimental group, which indicated that the digestive enzyme secreted by probiotics could improve the digestion and absorption rate of prawn feed, thus promoting the rapid growth of shrimp; The Shannon index, Simpson index and McIntosh index of probiotics groups showed significant difference in 1st and 5th days, but tended to be the same in the 10th day, the results showed that probiotics could maintain in L. vannamei intestines at least 5 days.

Doxycycline Attenuates Pig Intestinal Microbial Interactions and Changes Microbial Metabolic Pathways.

Doxycycline is a therapeutic veterinary antibiotic commonly used in pig breeding. In this study, 27 fattening pigs of 33.5 ± 0.72 kg were divided equally into 3 groups. Doxycycline at 0, 3, and 5 mg/kg body weight was added to the feed in groups CK, L and H. The medication and withdrawal periods were set at 5 and 28 days. The results showed that the doxycycline average concentrations in groups L and H during the medication period were 117.63 ± 13.54 and 202.03 ± 24.91 mg/kg dry matter, respectively. Doxycycline levels were lower than the detection limit after 20 days. Doxycycline did not affect the diversity of the intestinal microbial community structure. The relative abundances of Streptococcus were significantly higher in treatment groups than that in group CK, and Alishewanella, Vagococcus, Cloacibacterium, and Campylobacter abundances were significantly positively correlated with doxycycline concentration. Interestingly, the microbiota cooccurrence network suggested that high doxycycline concentration weakened the interactions among bacteria until day 33. Functional prediction showed that doxycycline significantly altered metabolic pathways related to the cell membrane. The results revealed that the use of doxycycline during pig breeding can affect bacterial abundance during the withdrawal period, and it may affect interactions among bacteria and change the intestinal metabolic pathways.

Identification of Intestinal Microbial Community in Gallstone Patients with Metagenomic Next-Generation Sequencing.

Gallstone disease (GD) is one of the most common gastrointestinal diseases worldwide. Nowadays, intestinal microbiota are thought to play important roles in the formation of gallstones. In our study, human fecal samples were extracted for metagenomic next-generation sequencing (mNGS) on the Illumina HiSeq platform, followed by bioinformatics analyses. Our results showed that there was a particular intestinal micro-ecosystem in GD patients. In contrast to healthy people, the sequences of Bacteroidetes, Bacteroides and Thetaiotaomicron were obviously more abundant in GD patients at phylum, genus and species levels, respectively. On the other hand, the glycan metabolism and drug resistance, especially for the ß-lactams, were the most profound functions of gut microbes in GD patients compared to those in normal subjects. Furthermore, a correlation analysis drew out that there existed a significant relationship between the serum levels of biochemical indicators and abundances of intestinal microbes in GD patients. Our results illuminate both the composition and functions of intestinal microbiota in GD patients. All in all, our study can broaden the insight into the potential mechanism of how gut microbes affect the progression of gallstones to some extent, which may provide potential targets for the prevention, diagnosis or treatment of GD.

Human Adult Microbiota in a Static Colon Model: AhR Transcriptional Activity at the Crossroads of Host-Microbe Interaction.

Functional symbiotic intestinal microbiota regulates immune defense and the metabolic processing of xenobiotics in the host. The aryl hydrocarbon receptor (AhR) is one of the transcription factors mediating host-microbe interaction. An in vitro static simulation of the human colon was used in this work to analyze the evolution of bacterial populations, the microbial metabolic output, and the potential induction of AhR transcriptional activity in healthy gut ecosystems. Fifteen target taxa were explored by qPCR, and the metabolic content was chromatographically profiled using SPME-GC-MS and UPLC-FLD to quantify short-chain fatty acids (SCFA) and biogenic amines, respectively. Over 72 h of fermentation, the microbiota and most produced metabolites remained stable. Fermentation supernatant induced AhR transcription in two of the three reporter gene cell lines (T47D, HepG2, HT29) evaluated. Mammary and intestinal cells were more sensitive to microbiota metabolic production, which showed greater AhR agonism than the 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) used as a positive control. Some of the SCFA and biogenic amines identified could crucially contribute to the potent AhR induction of the fermentation products. As a fundamental pathway mediating human intestinal homeostasis and as a sensor for several microbial metabolites, AhR activation might be a useful endpoint to include in studies of the gut microbiota.

Dietary Supplementation With Citrus Extract Altered the Intestinal Microbiota and Microbial Metabolite Profiles and Enhanced the Mucosal Immune Homeostasis in Yellow-Feathered Broilers.

The present study aimed to investigate the effects of citrus extract (CE) on intestinal microbiota, microbial metabolite profiles, and the mucosal immune status in broilers. A total of 540 one-day-old yellow-feathered broilers were randomly allotted into three groups and fed a basal diet (control group), or a basal diet containing 10 mg/kg of zinc bacitracin (antibiotic group), or 10 mg/kg of CE (CE group). Each treatment consisted of six replicates, with 30 broilers per replicate. After 63-day feeding, two broilers per replicate were randomly selected and slaughtered, and their ileal and cecal digesta and ileal tissue were collected for microbial composition, microbial metabolites, and gene expression analysis. The results showed that CE significantly increased the abundance of Barnesiella and Blautia than did the antibiotic group (adjusted P < 0.05), whereas it decreased the abundance of Alistipes and Bacteroides (adjusted P < 0.05). Meanwhile, the CE group also increased the numbers of Bifidobacterium and Lactobacillus than did the control and antibiotic groups (P < 0.05), whereas it decreased the number of Escherichia coli (P < 0.05). For microbial metabolites, dietary supplementation with CE increased the concentrations of lactate, total short-chain fatty acids, acetate, and butyrate in the cecum than did the control and antibiotic groups (P < 0.05), whereas it decreased the concentrations of amino acid fermentation products (ammonia, amines, p-cresol, and indole) (P < 0.05). Additionally, supplementation with CE up-regulated (P < 0.05) the mRNA expression of intestinal barrier genes (ZO-1 and Claudin) in the ileum than did both the control and antibiotic groups. However, antibiotic treatment induced gut microbiota dysbiosis, altered the microbial metabolism, and disturbed the innate immune homeostasis. In summary, these results provide evidence that dietary supplementation with CE can improve the intestinal barrier function by changing microbial composition and metabolites, likely toward a host-friendly gut environment. This suggests that CE may possibly act as an efficient antibiotic alternative for yellow-feathered broiler production.