Composition of the Microbial Community of the Small Intestine of Rats under Conditions of Restraint Stress of Varying Duration.

BackgroundThe intestinal microbiota is involved in pathogenesis of systemic inflammation in chronic heart failure (HF). The results of several previous studies suggest the need to evaluate the effects of prebiotics in HF. The current study aimed to evaluate the dietary addition of a prebiotic complex on dynamic changes of the mucosa‐associated intestinal microbiota and endotoxemia in rats with experimental HF.MethodsThe study was conducted on 30 adult female rats in accordance with the “Principles of Laboratory Animal Care”. The animals were divided in 3 groups: 1) control (n=10), 2) HF only (n=10) and 3) HF with addition of a prebiotic complex (HF‐P; n=10). Experimental HF was induced by daily subcutaneous injection of phenylephrine (5 mg/kg/day) followed by swimming exercise until exhaustion for 14 days. In HF‐P group, the animal diet was supplemented with a prebiotic complex, containing wheat bran fermented with Saccharomyces cerevisiae culture (“Eubikor”, St. Petersburg, Russia), starting 7 days before the induction of HF and throughout the study, in a concentration of 2.5 g/kg of body weight. At the end of experimental period, the blood samples were collected from the hearts. The plasma concentration of the endotoxin (lipopolysaccharides [LPS]; nmol/ml) and the microbial markers (higher fatty acids, aldehydes and sterols) with subsequent calculation of the microbial numbers within the intestinal mucous layer (cells/gram×105 ) were determined using the mass spectrometry method. Statistical data analysis was carried out with the PAST 3 software package.ResultsAll animals in experimental groups demonstrated clinical symptoms of HF that was later confirmed by histological examination. The rats in HF group demonstrated significant increase in the concentration of LPS (p = 0.025) and the number of gram‐negative Prevotella spp. (p = 0.015), Fusobacterium spp. (p = 0.008), Kingella spp. (p = 0.06); gram‐positive Enterococcus spp. (p = 0.025), Clostridium propionicum (p = 0.008), Lactobacillus spp. (p = 0.015) bacteria. Furthermore, the number of gut commensal bacteria, such as Bifidobacterium spp., Propionibacterium freudenreichii and Eubacterium spp., was tended to be decreased (p <0.1). The use of a prebiotic complex in HF rats led to a significant increase in the number of the commensal flora, particularly Bifidobacterium spp. (p = 0.025), Propionibacterium freudenreichii. (p = 0.01) and Eubacterium spp. (p = 0.01). Moreover, the animals in HF‐P group revealed a significant decrease in the plasma level of LPS (p = 0.016) and the number of Prevotella spp. (p = 0.01), Fusobacterium spp. (p = 0.005), Helicobacter pylori (p = 0.025), Enterococcus spp. (p = 0.01), Actinomyces viscosus (p = 0.025), Lactobacillus spp. (p = 0.037) bacteria and microscopic fungi producing campesterol and sitosterol (p = 0.016).ConclusionThe findings in our study demonstrate that the addition of a prebiotic complex to the diet of HF rats affects the dynamic changes of the intestinal microbiota and decreases the plasma endotoxin level. Taken together, our results provide strong support to the potential use of a prebiotic complex as a beneficial supplement to the treatment of HF patients.

BackgroundThe intestinal microbiome represents a complex network of microbes that are important for human health and preventing pathogen invasion. Studies that examine differences in intestinal microbial communities across individuals with and without enteric infections are useful for identifying microbes that support or impede intestinal health.Results16S rRNA gene sequencing was conducted on stool DNA from patients with enteric infections (n = 200) and 75 healthy family members to identify differences in intestinal community composition. Stools from 13 patients were also examined post-infection to better understand how intestinal communities recover. Patient communities had lower species richness, evenness, and diversity versus uninfected communities, while principle coordinate analysis demonstrated close clustering of uninfected communities, but not the patient communities, irrespective of age, gender, and race. Differences in community composition between patients and family members were mostly due to variation in the abundance of phyla Proteobacteria, Bacteroidetes, and Firmicutes. Patient communities had significantly more Proteobacteria representing genus Escherichia relative to uninfected communities, which were dominated by Bacteroides. Intestinal communities from patients with bloody diarrhea clustered together in the neighbor-joining phylogeny, while communities from 13 patients’ post-infection had a significant increase in Bacteroidetes and Firmicutes and clustered together with uninfected communities.ConclusionsThese data demonstrate that the intestinal communities in patients with enteric bacterial infections get altered in similar ways. Furthermore, preventing an increase in Escherichia abundance may be an important consideration for future prevention strategies.Electronic supplementary materialThe online version of this article (doi:10.1186/s40168-015-0109-2) contains supplementary material, which is available to authorized users.

Chronic intermittent stress exposure and access to grass silage interact differently in their effect on behaviour, gastric health and stress physiology of entire or castrated male growing-finishing pigs

To reveal the relationship of the bacterial communities in shrimp intestine and surrounding environments. We examined bacterial communities in the intestine of pacific white shrimp, Litopenaeus vannamei, the surrounding water and sediment by high-throughput sequencing analysis. Sequences were clustered into operational taxonomic units (OTUs) at 97% similarity levels, which ranged from 4956 to 5976 in each sample. All OTUs were affiliated with at least 64 phyla. The 10 most abundant phyla were Proteobacteria, Cyanobacteria, Bacteroidetes, Chloroflexi, Firmicutes, Acidobacteria, Actinobacteria, Planctomycetes, Gemmatimonadetes and Verrucomicrobia. The relationship of bacterial communities in the intestine and the surroundings was also investigated. A total of 1395 OTUs shared in the three habitats, accounting for 80, 65 and 77% in the intestine, the surrounding water and sediment respectively. There were 352, 891, 833 unique OTUs in intestine, surrounding water and sediment. Welch's t-test analysis showed that the abundances of some taxa were significantly different between the shrimp intestine and surroundings. Unweighted pair-group method with arithmetic mean analysis revealed that there was a generally similar bacterial community composition in three environments. These results showed that the bacterial compositions are mostly the same in shrimp intestine, water and sediment, but with different relative abundances of the bacterial communities. This study provided valuable findings on the relationship of the bacterial communities in shrimp intestine, the surrounding water and sediment, which can expand our knowledge of the broad trend on bacterial community in shrimp cultural ecosystems.

Background: Most of the population in the different areas of world is affected by bacterial infections responsible for dental caries. Due to the importance of traditional medicines derived from herbs used for dental problems, this study investigated in vitro antibacterial activity of Mentha longifolia essential oil from Ardabil, Iran, on Streptococcus mutans, Lactobacillus rhamnosus and Actinomyces viscosus, bacteria that cause tooth decay. Materials and Methods: The volatile oil of Mentha longifolia leaves was extracted by hydrodistilla tion method using a Clevenger-type apparatus and analyzed by GC and GC/MS system.The antibacterial activity was evaluated by the disk diffusion susceptibility in dilutions of 62.5, 125, 250, 500, 1000 and 2000�� g/�� l and broth macrodilution test methods. Results: The oil was particularly rich in Pulegone (31.78%), 1,8-cineole (15.99%), menthoforan (11.25%), cis-isopulegon (10.5%) and paramenth-3-n-8-l (6.85%). The medicinal plant essential oil could prevent the growth of the bacteria, and the rates of MIC and MBC of native pennyroyal essential oil on Streptococcus mutans, Lactobacillus rhamnosus and Actinomyces viscosus were 110, 165, 80, 120, 450 and 650�� g/�� l, respectively. The maximum inhibition zone diameter was about 12.2, 27.2 and 4.8 mm, for Streptococcus mutans, Lactobacillus rhamnosus and Actinomyces viscosus respectively, at the concentration of 500��J�� l -1 . Conclusion: In this work, the essential oil of medicinal plant containing effective ingredients could prevent the growth of bacteria and may be used as an affordable and available source for medicinal purposes.

Thirty-four caries-free teeth destined for orthodontic extraction were banded to provide a protected area for the accumulation of plaque. The teeth were extracted at one, two, four, eight, and 14 days after being banded, and samples of the flora below the band were analyzed for the presence of Streptococcus sanguis, Streptococcus 'mitior', 'mutans streptococci', Actinomyces viscosus, Actinomyces naeslundii, Actinomyces odontolyticus, Lactobacillus species, and Veillonella. After plaque sampling, the teeth were sent to the Royal Dental College (Copenhagen) for histological analysis. The results showed that S. mutans could colonize the area below the band after one day, but that colonization was only 100% at 14 days. Lactobacillus was only isolated from 2/8 samples at four days and from 4/8 samples at 14 days. S. sanguis and 'S. mitior' were regularly isolated at all banding times, and Veillonella was isolated from all samples. A. viscosus was the most commonly isolated Actinomyces. The numbers of Streptococcus and Veillonella were significantly higher at day 1 than at day 14 (p less than 0.05). S. mutans and A. viscosus were isolated more frequently at day 14 than at day 1 (p less than 0.01). Histological examination revealed that dissolution of the enamel below a band could occur after two days, but that even after 14 days dissolution could be questionable. Dissolution was detected in areas where S. mutans was not isolated (8/34), but S. mutans was also present in samples showing dissolution (12/34). There was no relationship between dissolution and the numbers of S. mutans; however, the isolation frequency of S. mutans was associated with dissolution (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Microglial-glucocorticoid receptor depletion alters the response of hippocampal microglia and neurons in a chronic unpredictable mild stress paradigm in female mice

To compare the soil and fish intestinal bacterial communities between traditional (TRF) and modern (MRF) rice-fish co-culture system, examining the impact of feed supplementation. High-throughput 16S rRNA gene sequencing was used to assess structure, diversity, composition, and functional predictions in soil and intestinal communities between TRF and MRF systems in Qingtian, Zhejiang Province, China. Key findings revealed that both soil and fish intestinal bacterial communities in the MRF system exhibited higher diversity and richness than those in the TRF. In soil, Pseudomonadota dominated both systems. MRF enriched Bacillota, whereas TRF enriched oligotrophy-linked Acidobacteriota and Chloroflexota. In intestine, TRF was Fusobacteriota-centered with Cetobacterium and Aeromonas dominance. While MRF was more even, with higher Bacillota, Actinomycetota, Clostridium and Mycobacterium. Which consistent with adaptation to formulated feeds. Rice yields remained unchanged, suggesting microbial buffering of nutrient input. Functional prediction (COG) indicated that MRF microbiota were enriched in carbohydrate metabolism and signal transduction, whereas TRF favored biosynthetic pathways. These findings offer insights for sustainable rice-fish co-culture system.

BackgroundThe gut microbiome has been linked to many diseases with sex bias including autoimmune, metabolic, neurological, and reproductive disorders. While numerous studies report sex differences in fecal microbial communities, the role of the reproductive axis in this differentiation is unclear and it is unknown how sex differentiation affects microbial diversity in specific regions of the small and large intestine.MethodsWe used a genetic hypogonadal mouse model that does not produce sex steroids or go through puberty to investigate how sex and the reproductive axis impact bacterial diversity within the intestine. Using 16S rRNA gene sequencing, we analyzed alpha and beta diversity and taxonomic composition of fecal and intestinal communities from the lumen and mucosa of the duodenum, ileum, and cecum from adult female (n = 20) and male (n = 20) wild-type mice and female (n = 17) and male (n = 20) hypogonadal mice.ResultsBoth sex and reproductive axis inactivation altered bacterial composition in an intestinal section and niche-specific manner. Hypogonadism was significantly associated with bacteria from the Bacteroidaceae,Eggerthellaceae,Muribaculaceae, and Rikenellaceae families, which have genes for bile acid metabolism and mucin degradation. Microbial balances between males and females and between hypogonadal and wild-type mice were also intestinal section-specific. In addition, we identified 3 bacterial genera (EscherichiaShigella, Lachnoclostridium, and Eggerthellaceaegenus) with higher abundance in wild-type female mice throughout the intestinal tract compared to both wild-type male and hypogonadal female mice, indicating that activation of the reproductive axis leads to female-specific differentiation of the gut microbiome. Our results also implicated factors independent of the reproductive axis (i.e., sex chromosomes) in shaping sex differences in intestinal communities. Additionally, our detailed profile of intestinal communities showed that fecal samples do not reflect bacterial diversity in the small intestine.ConclusionsOur results indicate that sex differences in the gut microbiome are intestinal niche-specific and that sampling feces or the large intestine may miss significant sex effects in the small intestine. These results strongly support the need to consider both sex and reproductive status when studying the gut microbiome and while developing microbial-based therapies.

Ammonia nitrogen stress induces dysbiosis of the intestinal bacterial community and facilitates the enrichment of pathogenic bacteria in intestines of shrimp

Stimulation of the innate immune system prior to stress exposure is a possible strategy to prevent depression under stressful conditions. Based on the innate immune system stimulating activities of zymosan A, we hypothesize that zymosan A may prevent the development of chronic stress-induced depression-like behavior. Our results showed that a single injection of zymosan A 1 day before stress exposure at a dose of 2 or 4 mg/kg, but not at a dose of 1 mg/kg, prevented the development of depression-like behaviors in mice treated with chronic social defeat stress (CSDS). The prophylactic effect of a single zymosan A injection (2 mg/kg) on CSDS-induced depression-like behaviors disappeared when the time interval between zymosan A and stress exposure was extended from 1 day or 5 days to 10 days, which was rescued by a second zymosan A injection 10 days after the first zymosan A injection and 4 days (4×, once daily) of zymosan A injections 10 days before stress exposure. Further analysis showed that a single zymosan A injection (2 mg/kg) 1 day before stress exposure could prevent the CSDS-induced increase in pro-inflammatory cytokines in the hippocampus and prefrontal cortex. Inhibition of the innate immune system by pretreatment with minocycline (40 mg/kg) abolished the preventive effect of zymosan A on CSDS-induced depression-like behaviors and CSDS-induced increase in pro-inflammatory cytokines in the brain. These results suggest that activation of the innate immune system triggered by zymosan A prevents the depression-like behaviors and neuroinflammatory responses in the brain induced by chronic stress.

High susceptibility to chronic social stress is associated with a depression-like phenotype

Stress exposure is known to be a risk factor for alcohol use and anxiety disorders. Comorbid chronic stress and alcohol dependence may lead to a complicated and potentially severe treatment profile. To gain an understanding of the interaction between chronic psychosocial stress and drug exposure, we studied the effects of concomitant chronic stress exposure on alcohol reward using two-bottle choice and ethanol-conditioned place preference (CPP). The study consisted of exposure of the chronic subordinate colony (CSC) mice “intruders” to an aggressive “resident” mouse for 19 consecutive days. Control mice were single housed (SHC). Ethanol consumption using two-bottle choice paradigm and ethanol CPP acquisition was assessed at the end of this time period. As expected, CSC exposure increased anxiety-like behavior and reduced weight gain as compared to SHC controls. Importantly, in the two-bottle choice procedure, CSC mice showed higher alcohol intake than SHC. When testing their response to ethanol-induced CPP, CSC mice achieved higher preference for the ethanol-paired chamber. In fact, CSC exposure increased ethanol-CPP acquisition. Taken together, these data demonstrate the long-term consequences of chronic psychosocial stress on alcohol intake in male mice, suggesting chronic stress as a risk factor for developing alcohol consumption and/or anxiety disorders.

Metabolic consequences of chronic intermittent mild stress exposure

Helicobacter pylori (HP) infection usually occurs in childhood. While there are various studies on the prevalence of HP in dental plaque, ours is the first to analyze its prevalence during orthodontic therapy and its interaction with competitive bacteria in adolescents. The prevalence of HP was examined before and during the first 12weeks of orthodontic therapy with fixed appliances in 11patients with a mean age of 12.7years. A total of 93plaque samples were analyzed using PCR. The data acquired at every consultation were the following: PCR analysis of dental plaque and (13)C urea breath tests for HP, quantitative analyses of saliva for Lactobacilli and Streptococcus mutans, the interproximal plaque index (API), and sulcus bleeding index (SBI). The prevalence of HP in plaque was 82% before orthodontic therapy, dropping to 54% during therapy (t test, p≤0.05). In contrast to HP's prevalence, the Lactobacilli count rose (p≤0.05). The number of Streptococcus mutans bacteria in saliva decreased during orthodontic therapy (p≤0.05). The prevalence of HP in dental plaque amounted to 82%. Orthodontic treatment did not reduce its prevalence. The prevalence of Lactobacilli was inversely proportional to that of HP.