Microbiota Of Animals Research Articles

The Host Microbiota Contributes to Early Protection Against Lung Colonization by Mycobacterium tuberculosis.

Tuberculosis (TB), caused by the airborne bacterial pathogen Mycobacterium tuberculosis, remains a major source of morbidity and mortality worldwide. So far, the study of host-pathogen interactions in TB has mostly focused on the physiology and virulence of the pathogen, as well as, on the various innate and adaptive immune compartments of the host. Microbial organisms endogenous to our body, the so-called microbiota, interact not only with invading pathogens, but also with our immune system. Yet, the impact of the microbiota on host defense against M. tuberculosis remains poorly understood. In order to address this question, we adapted a robust and reproducible mouse model of microbial dysbiosis based on a combination of wide-spectrum antibiotics. We found that microbiota dysbiosis resulted in an increased early colonization of the lungs by M. tuberculosis during the first week of infection, correlating with an altered diversity of the gut microbiota during this time period. At the cellular level, no significant difference in the recruitment of conventional myeloid cells, including macrophages, dendritic cells and neutrophils, to the lungs could be detected during the first week of infection between microbiota-competent and -deficient mice. At the molecular level, microbiota depletion did not impact the global production of pro-inflammatory cytokines, such as interferon (IFN)γ, tumor necrosis factor (TNF)α and interleukin (IL)-1β in the lungs. Strikingly, a reduced number of mucosal-associated invariant T (MAIT) cells, a population of innate-like lymphocytes whose development is known to depend on the host microbiota, was observed in the lungs of the antibiotics-treated animals after 1week of infection. These cells produced less IL-17A in antibiotics-treated mice. Notably, dysbiosis correction through the inoculation of a complex microbiota in antibiotics-treated animals reversed these phenotypes and improved the ability of MAIT cells to proliferate. Altogether, our results demonstrate that the host microbiota contributes to early protection of lung colonization by M. tuberculosis, possibly through sustaining the function(s) of MAIT cells. Our study calls for a better understanding of the impact of the microbiota on host-pathogen interactions in TB. Ultimately, this study may help to develop novel therapeutic approaches based on the use of beneficial microbes, or components thereof, to boost anti-mycobacterial immunity.

Effects of Lactococcus lactis subsp. lactis JCM5805 on colonization dynamics of gut microbiota and regulation of immunity in early ontogenetic stages of tilapia

The administration of probiotics during early ontogenetic stages can be an effective way to manipulate the gut microbiota of animals. Specifically, the administration of probiotics can enhance gut-colonization success and regulate the immune response. In this study, the effects of early contact with probiotic Lactococcus lactis subsp. lactis JCM5805 on the gut microbial assembly of larvae Nile tilapia were examined. The effects of JCM5805 on IFNα expression through the TLR7 and TLR9-dependent signal transduction pathway as well as larval disease resistance were studied. Three days postfertilization, embryos were randomly allocated into nine 30 L tanks with a concentration of 20 eggs L−1. Triplicate tanks were performed for each treatment. Treatments included a control group (C), a low probiotic concentration group (T1), where JCM5805 was added to the water at 1 × 104 cfu ml−1, and a high probiotic concentration group (T2), where JCM5805 was added to the water at 1 × 108 cfu ml−1. Probiotics were administered continuously for 15 days. qPCR was used to analyze transcript levels of the TLR7, TLR9, MyD88, IRF7 and IFNα genes using RNA extracted from whole embryos on day 5 and 10, and from the intestine of larvae on day 15. Transcription of these genes was also measured in the intestine, liver and spleen of larvae one month after the cessation of probiotic administration. The results showed that MyD88 and IRF7 were significantly elevated on days 5 and 10 in the T2 group. TLR9 and IFNα were also significantly elevated on days 5, 10 and 15 during probiotic application of T2 (P < 0.05). One month after the cessation of probiotics administration, no significant difference was observed in the expression of these genes (P > 0.05). The larvae were fed probiotics for 15 days and were infused with Streptococcus agalactiae strain WC1535 at a final concentration of 1 × 106 cfu ml−1. The survival rate of T2 was significantly higher than that of the C group (P < 0.05). Microbial characterization by Illumina HiSeq sequencing of 16S rRNA gene amplicons showed the significantly higher presence of JCM5805 in the guts of T2 after 15 days of probiotic continuous application. Although JCM5805 was below the detection level after the cessation of probiotic for 5 days, the gut microbiota of the exposed tilapia larvae in T2 remained clearly different from that of the control treatment after the cessation of probiotic administration. These data indicated that a high concentration of the probiotic strain JCM5805 upregulated the expression of IFNα via the TLR7/TLR9-Myd88 pathway and enhanced disease resistance of larvae. JCM5805 was only transiently detected and thus was not included in the stable larval microbiota. The early microbial exposure of tilapia larvae affects the gut microbiota at later life stages. However, whether the upregulation of related genes is related to the presence of JCM5805 strain in the intestine requires further verification.

Dynamic Distribution of Gut Microbiota in Goats at Different Ages and Health States.

The importance of the gut microbiota (GM) of animals is widely acknowledged because of its pivotal roles in metabolism, immunity, and health maintenance. The level of health can be reflected by the dynamic distribution of GM. In this study, high-throughput sequencing of the bacterial 16S rRNA gene was used to compare the microbial populations from feces in healthy and diarrheic kids, which reflected the dynamic shift of microbiota in kids and investigated differences from adult healthy goats. Healthy kids and goats not only displayed higher species richness but also exhibited higher bacterial diversity than diarrheic kids based on the results of the operational taxonomic unit analysis, alpha diversity, and beta diversity. Firmicutes and Bacteroidetes were the most dominant phyla in all samples. At the genus level, the differences in diversity and abundance between diarrheic kids and the other two groups were gradually observed. In the diarrheic kid intestine, Bacteroides remained the dominant species, and the proportion of Clostridium_sensu_stricto_1 and Paeniclostridium increased, whereas Rikenellaceae_RC9_gut_group, Ruminococcaceae_UCG-005, and Christensenellaceae_R-7_group were significantly reduced. The results showed the differences of GM in diarrheic kids and healthy kids were significant while in kids and goats were not obvious. Differences in the composition of intestinal microbiota may not be the cause of diarrhea, and some changes of bacterial richness may guide our interpretation of diarrhea. This study is the first to investigate the distribution of GM in Boer goats with different ages and health states. Furthermore, this study will provide a theoretical basis for the establishment of a prevention and treatment system for goat diarrhea.

Implications of the expression of Enterococcus faecalis citrate fermentation genes during infection.

Citrate is an ubiquitous compound in nature. However, citrate fermentation is present only in a few pathogenic or nonpathogenic microorganisms. The citrate fermentation pathway includes a citrate transporter, a citrate lyase complex, an oxaloacetate decarboxylase and a regulatory system. Enterococcus faecalis is commonly present in the gastro-intestinal microbiota of warm-blooded animals and insect guts. These bacteria can also cause infection and disease in immunocompromised individuals. In the present study, we performed whole genome analysis in Enterococcus strains finding that the complete citrate pathway is present in all of the E. faecalis strains isolated from such diverse habitats as animals, hospitals, water, milk, plants, insects, cheese, etc. These results indicate the importance of this metabolic preservation for persistence and growth of E. faecalis in different niches. We also analyzed the role of citrate metabolism in the E. faecalis pathogenicity. We found that an E. faecalis citrate fermentation-deficient strain was less pathogenic for Galleria mellonella larvae than the wild type. Furthermore, strains with deletions in the oxaloacetate decarboxylase subunits or in the α-acetolactate synthase resulted also less virulent than the wild type strain. We also observed that citrate promoters are induced in blood, urine and also in the hemolymph of G. mellonella. In addition, we showed that citrate fermentation allows E. faecalis to grow better in blood, urine and G. mellonella. The results presented here clearly indicate that citrate fermentation plays an important role in E. faecalis opportunistic pathogenic behavior.

Non-invasive continuous real-time in vivo analysis of microbial hydrogen production shows adaptation to fermentable carbohydrates in mice

Real time in vivo methods are needed to better understand the interplay between diet and the gastrointestinal microbiota. Therefore, a rodent indirect calorimetry system was equipped with hydrogen (H2) and methane (CH4) sensors. H2 production was readily detected in C57BL/6J mice and followed a circadian rhythm. H2 production was increased within 12 hours after first exposure to a lowly-digestible starch diet (LDD) compared to a highly-digestible starch diet (HDD). Marked differences were observed in the faecal microbiota of animals fed the LDD and HDD diets. H2 was identified as a key variable explaining the variation in microbial communities, with specific taxa (including Bacteroides and Parasutterella) correlating with H2 production upon LDD-feeding. CH4 production was undetectable which was in line with absence of CH4 producers in the gut. We conclude that real-time in vivo monitoring of gases provides a non-invasive time-resolved system to explore the interplay between nutrition and gut microbes in a mouse model, and demonstrates potential for translation to other animal models and human studies.

How Can We Define “Optimal Microbiota?”: A Comparative Review of Structure and Functions of Microbiota of Animals, Fish, and Plants in Agriculture

All multicellular organisms benefit from their own microbiota, which play important roles in maintaining the host nutritional health and immunity. Recently, the number of studies on the microbiota of animals, fish, and plants of economic importance is rapidly expanding and there are increasing expectations that productivity and sustainability in agricultural management can be improved by microbiota manipulation. However, optimizing microbiota is still a challenging task because of the lack of knowledge on the dominant microorganisms or significant variations between microbiota, reflecting sampling biases, different agricultural management as well as breeding backgrounds. To offer a more generalized view on microbiota in agriculture, which can be used for defining criteria of “optimal microbiota” as the goal of manipulation, we summarize here current knowledge on microbiota on animals, fish, and plants with emphasis on bacterial community structure and metabolic functions, and how microbiota can be affected by domestication, conventional agricultural practices, and use of antimicrobial agents. Finally, we discuss future tasks for defining “optimal microbiota,” which can improve host growth, nutrition, and immunity and reduce the use of antimicrobial agents in agriculture.

Sensitivity to antimicrobials of faecal Buttiauxella spp. from roe and red deer (Capreolus capreolus, Cervus elaphus)detected with MALDI-TOF mass spectrometry.

Wild ruminants are an interesting topic for research because only limited information exists regarding their microbiota. They could also be an environmental reservoir of undesirable bacteria for other animals or humans. In this study faeces of the 21 free-living animals was sampled (9 Cervus elaphus-red deer, adult females, 12 Capreolus capreolus-roe deer, young females). They were culled by selective-reductive shooting during the winter season of 2014/2015 in the Strzałowo Forest District-Piska Primeval Forest (53° 36 min 43.56 sec N, 21° 30 min 58.68 sec E) in Poland. Buttiauxella sp. is a psychrotolerant, facultatively anaerobic, Gram-negative rod anaerobic bacte- rial species belonging to the Phylum Proteobacteria, Class Gammaproteobacteria, Order Entero- bacteriales, Family Enterobacteriacae and to Genus Buttiauxella. Buttiauxella sp. has never previ- ously been reported in wild ruminants. In this study, identification, antimicrobial profile and sensitivity to enterocins of Buttiauxella strains were studied as a contribution to the microbiota of wild animals, but also to extend knowledge regarding the antimicrobial spectrum of enterocins. Five strains were identified using the MALDI-TOF identification system (evaluation score value was up to 2.224) and allotted to the genus Buttiauxella including the species Buttiauxella gaviniae, B. ferragutiae, B. agrestis. Strains were DNase negative, and they hydrolysed esculin; fermentation of L-arabinose, D-mannitol and D-mannose was positive. Dulcitol, inositol reaction, urea and indol were negative. Buttiauxella strains did not form biofilm. They were resistant to at least one of the 13 antibiotics tested. B. agrestis 2/109/1 was resistant to amdinocillin, clindamycin and pen- icillin. However, Buttiauxella strains were sensitive to the enterocins used (inhibition activity ranged from 100 to 25 600 AU/ml).

Using bioreactors to study the effects of drugs on the human microbiota.

The study of complex microbial communities has become a major research focus as mounting evidence suggests the pivotal role microbial communities play in host health and disease. Microbial communities of the gastrointestinal tract, known as the gut microbiota, have been implicated in aiding the host with vitamin biosynthesis, regulation of host energy metabolism, immune system development, and resistance to pathogen invasion. Conversely, disruptions of the gut microbiota have been linked to host morbidity, including the development of inflammatory diseases, metabolic disorders, increased cardiovascular risk, and increased risk of infectious diseases. However, studying the gut microbiota in humans and animals is challenging, as many microorganisms are fastidious with unique nutritional or environmental requirements that are often not met using conventional culture techniques. Bioreactors provide a unique solution to overcome some of the limitations of conventional culture techniques. Bioreactors have been used to propagate and establish complex microbial communities in vitro by recapitulating the physiological conditions found in the GI tract. These systems further our understanding of microbial physiology and facilitate our understanding of the impact of medications and xenobiotics on microbial communities. Here, we review the versatility and breadth of bioreactor systems that are currently available and how they are being used to study faecal and defined microbial communities. Bioreactors provide a unique opportunity to study complex microbial interactions and perturbations in vitro in a controlled environment without confounding biotic and abiotic variables.

Gut Microbiota of Great Spotted Cuckoo Nestlings is a Mixture of Those of Their Foster Magpie Siblings and of Cuckoo Adults.

Diet and host genetic or evolutionary history are considered the two main factors determining gut microbiota of animals, although studies are scarce in natural populations. The system of great spotted cuckoos (Clamator glandarius) parasitizing magpies (Pica pica) is ideal to study both effects since magpie adults feed cuckoo and magpie nestlings with the same diet and, consequently, differences in gut microbiota of nestlings of these two species will mainly reflect the importance of genetic components. Moreover, the diet of adults and of nestling cuckoos drastically differ from each other and, thus, differences and similarities in their microbiotas would respectively reflect the effect of environmental and genetic factors. We used next-generation sequencing technologies to analyze the gut microbiota of cuckoo adults and nestlings and of magpie nestlings. The highest α-diversity estimates appeared in nestling cuckoos and the lowest in nestling magpies. Moreover, despite the greatest differences in the microbiome composition of magpies and cuckoos of both ages, cuckoo nestlings harbored a mixture of the Operational Taxonomic Units (OTUs) present in adult cuckoos and nestling magpies. We identified the bacterial taxa responsible for such results. These results suggest important phylogenetic components determining gut microbiome of nestlings, and that diet might be responsible for similarities between gut microbiome of cuckoo and magpie nestlings that allow cuckoos to digest food provided by magpie adults.

A Comprehensive Research on Antibiotic Resistance Genes in Microbiota of Aquatic Animals.

The occurrence of antibiotic resistance genes (ARGs) as emerging contaminants is of continued concern for human health. Antibiotics used in aquaculture have promoted the evolution and spread of ARGs. This study aimed to investigate the occurrence of 37 ARGs conferring resistance to six classes of antibiotics in 94 aquatic animals from five cities in southeast coast of China. The results showed that floR, sulII, sulI, strB, strA, aadA, and tetS were identified as the prominent ARGs with the high detection frequencies ranging from 30.9 to 51.1% in total samples. Then relative expression amount of seven prominent ARGs quantified by qPCR, ranging from 0.003 to 0.065. The tetS was the most abundant ARG among the seven ARGs. Though aadA was the second highest detection frequency of ARGs, it was the lowest expression amount ARG. The occurrences and abundances of ARGs in freshwater aquatic animals were greater than those in marine, reflecting the discrepancy of cultivation pattern between the freshwater and marine aquaculture. Shanghai was considered as the most prevalent site with 16 ARGs, and Ningbo merely contained 9 ARGs without of β-lactam ARGs and quinolone ARGs, showing variations of ARGs with geographical location. Eight kinds of sulfonamides and one chloramphenicol residues were further measured in samples from Shanghai. Interestingly, no target antibiotics were found, but sulfonamides resistance genes (sulI, sulII) and chloramphenicol resistance genes (floR) persisted at aquatic animals in the absence of selection pressure. Our research firstly shows comprehensive information on the ARGs in skin microbiota of aquatic animals, which could provide useful information and a new insight for better understanding on the ARGs dissemination in aquatic animals.

High-Throughput Analysis Reveals Seasonal Variation of the Gut Microbiota Composition Within Forest Musk Deer (Moschus berezovskii).

The gut microbiota plays a key role in the nutritional ecology of ruminants, and host diet has a significant effect on these microbial communities. Longitudinal studies assessing variation of seasonal microbiota in animals can provide a comparative context for interpreting the adaptive significance of such changes. However, few studies have investigated the effects of seasonally-related dietary shifts on the gut microbial communities of endangered forest musk deer (FMD), and the national breeding programs need this information to promote the growth of captive populations. The present study applied bacterial 16S rRNA genes based on high-throughput sequencing to profile the fecal microbial communities of FMD across four seasons. Microbial diversity was higher in seasons with dry leaf diets (winter and spring) compared to seasons with fresh leaf diets (summer and autumn). The dominant microbial phyla were Firmicutes and Bacteroidetes, and the core bacterial taxa also comprised mostly (94.40% of shared OTUs) Firmicutes (37 taxa) and Bacteroidetes (6 taxa), which were relatively stable across different seasons. The Firmicutes–Bacteroidetes ratio declined in seasons with fresh leaf diets relative to seasons with dry leaf diets, and the dominant genera among the four seasons showed no significant variation in abundance. This work explores the seasonal variation in the microbial communities of FMD for the first time, and reveals how gut microbial community dynamics vary seasonally in accordance with differences in dietary plants (fresh and dry leaf). These results indicate that the annual cyclic reconfiguration of FMD gut microbiota could be associated with shifts in dietary nutrients, which is important information to inform captive FMD management.

Extracellular Electron Transfer by the Gram-Positive Bacterium Enterococcus faecalis.

Extracellular electron transfer (EET) in microbial cells is essential for certain biotechnological applications and contributes to the biogeochemical cycling of elements and syntrophic microbial metabolism in complex natural environments. The Gram-positive lactic acid bacterium Enterococcus faecalis, an opportunistic human pathogen, is shown to be able to transfer electrons generated in fermentation metabolism to electrodes directly and indirectly via mediators. By exploiting E. faecalis wild-type and mutant cells, we demonstrate that reduced demethylmenaquinone in the respiratory chain in the bacterial cytoplasmic membrane is crucial for the EET. Heme proteins are not involved, and cytochrome bd oxidase activity was found to attenuate EET. These results are significant for the mechanistic understanding of EET in bacteria and for the design of microbial electrochemical systems. The basic findings infer that in dense microbial communities, such as in biofilm and in the large intestine, metabolism in E. faecalis and similar Gram-positive lactic acid bacteria might be electrically connected to other microbes. Such atranscellular electron transfer might confer syntrophic metabolism that promotes growth and other activities of bacteria in the microbiota of humans and animals.

In vitro combination of antifungal agents against Malassezia pachydermatis.

The yeast Malassezia pachydermatis is a common commensal and occasional opportunistic pathogen of theskin microbiota of animals and humans. In this study, the susceptibility of M. pachydermatis isolates to fluconazole (FLC), itraconazole (ITZ), ketoconazole (KTZ), clotrimazole (CLZ), and miconazole (MCZ) alone and in combination with terbinafine (TRB), nystatin (NYS), and caspofungin (CSP) was evaluated in vitro based on the M27-A3 technique and the checkerboard microdilution method using Sabouraud dextrose broth with 1% tween 80 (SDB). Based on the mean FICI values, the main synergies observed were combinations of ITZ+CSP and CLZ+CSP (55.17%). The most significant combinations deserve in vivo evaluations because might provide effective alternative treatments against M. pachydermatis due to their synergistic interactions.

Metaproteomics method to determine carbon sources and assimilation pathways of species in microbial communities

Measurements of stable carbon isotope ratios (δ13C) are widely used in biology to address questions regarding food sources and metabolic pathways used by organisms. The analysis of these so-called stable isotope fingerprints (SIFs) for microbes involved in biogeochemical cycling and microbiota of plants and animals has led to major discoveries in environmental microbiology. Currently, obtaining SIFs for microbial communities is challenging as the available methods either only provide low taxonomic resolution, such as the use of lipid biomarkers, or are limited in throughput, such as nanoscale secondary ion MS imaging of single cells. Here we present "direct protein-SIF" and the Calis-p software package (https://sourceforge.net/projects/calis-p/), which enable high-throughput measurements of accurate δ13C values for individual species within a microbial community. We benchmark the method using 20 pure culture microorganisms and show that the method reproducibly provides SIF values consistent with gold-standard bulk measurements performed with an isotope ratio mass spectrometer. Using mock community samples, we demonstrate that SIF values can also be obtained for individual species within a microbial community. Finally, a case study of an obligate bacteria-animal symbiosis shows that direct protein-SIF confirms previous physiological hypotheses and can provide unexpected insights into the symbionts' metabolism. This confirms the usefulness of this approach to accurately determine δ13C values for different species in microbial community samples.

Staphylococcal pyoderma: challenges and therapeutic considerations

Superficial staphylococcal pyoderma is a common diagnosis in companion animal practice. The majority of cutaneous bacterial infections in dogs and cats are associated with Staphylococcus pseudintermedius , Staphylococcus aureus or...

MP70-17 DECIPHERING THE EFFECTS OF OMEGA-3 FATTY ACID SUPPLEMENTS ON PROSTATE CANCER

You have accessJournal of UrologyProstate Cancer: Basic Research & Pathophysiology III1 Apr 2018MP70-17 DECIPHERING THE EFFECTS OF OMEGA-3 FATTY ACID SUPPLEMENTS ON PROSTATE CANCER Gabriel Lachance, Nikunj Geveriya, Karine Robitaille, Alain Bergeron, Valérie Picard, Mickael Leclerc, Charles Joly, Yves Fradet, Arnaud Droit, André Marette, and Vincent Fradet Gabriel LachanceGabriel Lachance More articles by this author , Nikunj GeveriyaNikunj Geveriya More articles by this author , Karine RobitailleKarine Robitaille More articles by this author , Alain BergeronAlain Bergeron More articles by this author , Valérie PicardValérie Picard More articles by this author , Mickael LeclercMickael Leclerc More articles by this author , Charles JolyCharles Joly More articles by this author , Yves FradetYves Fradet More articles by this author , Arnaud DroitArnaud Droit More articles by this author , André MaretteAndré Marette More articles by this author , and Vincent FradetVincent Fradet More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2018.02.2261AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Inflammation is one contributing factors to prostate cancer (PCa). We have shown that an omega-3 (?3)-rich diet decrease PCa tumor growth by favourably modulating the inflammatory response. In this study, we tested the specific effects of purified ?3 fatty acids (FA) sub-types on tumor growth, inflammatory response, gut microbiota and tumor gene expression compared to ?6 and ?9 in a murine PCa model. METHODS C57BL/6 mice were daily supplemented with purified FA (?3-eicosapentaenoic acid (EPA), ?3-docosahexaenoic acid (DHA), ?6-arachidonic acid (AA) or ?9-rich high-oleic sunflower oil (HOSO)), and injected s.c. with TRAMP-C2 mouse PCa cells. Feces were collected weekly while blood and tumors were collected at end point. FA incorporation was analyzed in blood and tumors. Bacterial content from fresh fecal DNA was profiled using 16S rRNA metagenomic sequencing. Cytokine and gene expression profiles were analyzed in tumors using BioPlex technology and high-throughput RNA sequencing, respectively. RESULTS We measured a specific FA incorporation of each group into red blood and tumor cells. Interestingly, only tumors of EPA-fed mice had a reduced tumor growth than HOSO-fed control mice. Many pro-inflammatory cytokines were expressed at a significantly lower level in tumors of ?3-EPA and –DHA fed mice compared to ?6-AA-fed mice. We found gene expression changes only in the EPA-fed mice group: differentially expressed genes were related to angiogenesis and inflammatory pathways. We confirmed reduced expression of VEGFR and VEGF as well as smaller CD31-stained blood vessels in EPA-fed tumors. Finally, gut microbiota metagenomic analysis revealed that most bacterial shifts were found in DHA-fed animals. Interestingly, while we observed little changes for the gut microbiota of AA-fed animals, we were able to predict metagenome functional content and found an increase in functions associated to butirosin and neomycin biosynthesis, renal cell carcinoma and glycerophospholipid metabolism compared to control animals. CONCLUSIONS Both ?3 subtypes modulated intra-tumoral inflammation. Interestingly, DHA was the FA driving the biggest changes in fecal microbiota. However, we found only EPA to significantly reduce PCa tumor growth, potentially achieved by gene expression modulation leading to a reduced angiogenesis and inflammation. Together, these results suggest that both ?3 subtypes modulate inflammation but possibly via separate mechanisms. Our work supports the use of EPA for targeting PCa progression. © 2018FiguresReferencesRelatedDetails Volume 199Issue 4SApril 2018Page: e941 Advertisement Copyright & Permissions© 2018MetricsAuthor Information Gabriel Lachance More articles by this author Nikunj Geveriya More articles by this author Karine Robitaille More articles by this author Alain Bergeron More articles by this author Valérie Picard More articles by this author Mickael Leclerc More articles by this author Charles Joly More articles by this author Yves Fradet More articles by this author Arnaud Droit More articles by this author André Marette More articles by this author Vincent Fradet More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Can diets containing insects promote animal health?

Insects are promising feedstuffs for animal feeds as they contain not only valuable nutrients but also particular compounds that seem to be able to modulate animal microbiota and to optimise animal health. So far, there has been little work on the effects of those insect derived compounds in animal feeding trails but initial investigations show promising results. This editorial discuss the effect of chitin, lauric acid, and anti-microbial peptides provided by insects.

Rampant Host Switching Shaped the Termite Gut Microbiome

The gut microbiota of animals exert major effects onhost biology [1]. Although horizontal transfer is generally considered the prevalent route for the acquisition of gut bacteria in mammals [2], some bacterial lineages have co-speciated with their hosts on timescales of several million years [3]. Termites harbor a complex gut microbiota, and their advanced social behavior provides the potential for long-term vertical symbiont transmission, and co-evolution of gut symbionts and host [4-6]. Despite clear evolutionary patterns in the gut microbiota of termites [7], a consensus on how microbial communities were assembled during termite diversification has yet to be reached. Although some studies have concluded that vertical transmission has played a major role [8, 9], others indicate that diet and gut microenvironment have been the primary determinants shaping microbial communities in termite guts [7, 10]. To address this issue, we examined the gut microbiota of 94 termite species, through 16S rRNA metabarcoding. We analyzed the phylogeny of 211 bacterial lineages obtained from termite guts, including their closest relatives from other environments, which were identified using BLAST. The results provided strong evidence for rampant horizontal transfer of gut bacteria between termite host lineages. Although the majority of termite-derived phylotypes formed large monophyletic groups, indicating high levels of niche specialization, numerous other clades were interspersed with bacterial lineages from the guts of other animals. Our results indicate that "mixed-mode" transmission, which combines colony-to-offspring vertical transmission with horizontal colony-to-colony transfer, has been the primary driving force shaping the gut microbiota of termites.

The Dynamic Distribution of Small-Tail Han Sheep Microbiota across Different Intestinal Segments.

The sheep intestinal tract is characterized by a diverse microbial ecosystem that is vital for the host to digest diet material. The importance of gut microbiota (GM) of animals has also been widely acknowledged because of its pivotal roles in the health and well-being of animals. However, there are no relevant studies on GM of small-tail Han sheep, a superior mutton variety domestic in China. In this study, the structure and distribution of gut microflora were studied by high-throughput sequencing technology. Results showed a significant difference between jejunum and cecum, jejunum, and rectum. Meanwhile, the cecum and rectum not only display higher species richness but also exhibit higher similarity of the bacterial diversity than that of the jejunum based on the results of abundance-based coverage estimator (ACE), Chao1, and Shannon indexes. Firmicutes and Bacteroidetes were the predominant phyla in cecum and rectum, while higher relative abundances of Firmicutes and Cyanobacteria were observed in jejunum. At the genus level, Bacteroidetes, Ruminococcus, Lactobacillus, Flavonifractor, and Clostridium were the dominant genera in the cecum and rectum. An obvious dynamic distribution of Lactobacillus is continuously decreasing from the jejunum to the cecum, then to the rectum, whereas the result of Bacteroides is completely inverse. In addition, this study also found many kinds of bacteria associated with the production of volatile fatty acids (VFA) colonized in the large intestine. This study is the first to investigate the distribution of intestinal flora in small-tail Han sheep. The findings provide an important indication for diagnosis and treatment of intestinal diseases in small-tail Han sheep, as well as offer a direction for the development of intestinal microecological preparations.

Gut microbiome may contribute to insulin resistance and systemic inflammation in obese rodents: a meta-analysis.

A number of studies have associated obesity with altered gut microbiota, although results are discordant regarding compositional changes in the gut microbiota of obese animals. Herein we used a meta-analysis to obtain an unbiased evaluation of structural and functional changes of the gut microbiota in diet-induced obese rodents. The raw sequencing data of nine studies generated from high-fat diet (HFD)-induced obese rodent models were processed with QIIME to obtain gut microbiota compositions. Biological functions were predicted and annotated with KEGG pathways with PICRUSt. No significant difference was observed for alpha diversity and Bacteroidetes-to-Firmicutes ratio between obese and lean rodents. Bacteroidia, Clostridia, Bacilli, and Erysipelotrichi were dominant classes, but gut microbiota compositions varied among studies. Meta-analysis of the nine microbiome data sets identified 15 differential taxa and 57 differential pathways between obese and lean rodents. In obese rodents, increased abundance was observed for Dorea, Oscillospira, and Ruminococcus, known for fermenting polysaccharide into short chain fatty acids (SCFAs). Decreased Turicibacter and increased Lactococcus are consistent with elevated inflammation in the obese status. Differential functional pathways of the gut microbiome in obese rodents included enriched pyruvate metabolism, butanoate metabolism, propanoate metabolism, pentose phosphate pathway, fatty acid biosynthesis, and glycerolipid metabolism pathways. These pathways converge in the function of carbohydrate metabolism, SCFA metabolism, and biosynthesis of lipid. HFD-induced obesity results in structural and functional dysbiosis of gut microbiota. The altered gut microbiome may contribute to obesity development by promoting insulin resistance and systemic inflammation.