scholarly journals 2571. Norovirus Infection and Gut Microbiota in Transplant Recipients

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S893-S893
Author(s):  
Pearlie P Chong ◽  
Pearlie P Chong ◽  
Sarah K Hussain ◽  
Nicole Poulides ◽  
Laura Coughlin ◽  
...  

Abstract Background In vitro studies have shown that enteric viruses require the gut microbiota (specific members of the Enterobacteriaceae family) for efficient infection of the gastrointestinal tract. Human norovirus (NV) infection in transplant recipients may be chronic and severe. The role of gut microbiota has not been defined in this setting. We hypothesized that gut microbiota diversity and composition are different in norovirus-infected transplant patients. Methods We performed a single-center, pilot, prospective cohort study of adult solid-organ transplant and hematopoietic stem cell transplant recipients with diarrhea. Serial fecal samples were collected and processed for gDNA. Norovirus levels were quantified by PCR and gut microbiota profiling determined by 16S rRNA gene sequencing. Results Twenty-five transplant recipients were included: 9 with NV infection and 16 without. Age (61 ± SEM 2.3 years vs. 54 ± 3.5 years; P = 0.172), duration of diarrhea prior to diagnosis (105 ± 43 days vs. 20 ± 7 days; P = 0.146), prior cumulative antibiotic use (42 ± 12 days vs. 46 ± 17 days; P = 0.646), anti-anaerobic antibiotic use (7 ± 3 days vs. 11 ± 6 days; P = 0.643) and length of hospitalization (12 ± 6 days vs. 12 ± 3 days; P = 0.624) were not different between transplant recipients with and without NV infection. Interestingly, the relative abundance of Enterobactericeae was significantly higher in NV-infected transplant recipients compared with those without NV infection (26 ± 5.8% vs. 6.2 ± 2.8%; P = 0.017, Mann–Whitney) (Figure 1). In contrast, the abundance of the Phyla Bacteroidetes (11.2 ± 5.2% vs. 26.3 ± 6.5%; P = 0.191), and Firmicutes (26.8 ± 7.6% vs. 24.9 ± 4.7%; P = 0.803), were not significantly different between those who were NV and not NV-infected. Of note, the diversity metrics of Shannon (3.5 ± 0.4 vs. 3.8 ± 0.3; P = 0.637) and inverse Simpson indices (1.3 ± 0.1 vs. 1.1±0.1; P = 0.419) were not significantly different between the two groups. Conclusion Norovirus-infected transplant recipients had a significantly higher relative abundance of Enterobactericeae in their gut microbiota compared with transplant recipients without norovirus infection. Future studies are needed to explore if this association is mechanistically important for norovirus infection. Disclosures All authors: No reported disclosures.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Vanessa Palmas ◽  
Silvia Pisanu ◽  
Veronica Madau ◽  
Emanuela Casula ◽  
Andrea Deledda ◽  
...  

AbstractIn the present study, we characterized the distinctive signatures of the gut microbiota (GM) from overweight/obese patients (OB), and normal-weight controls (NW), both of Sardinian origin. Fecal bacterial composition of 46 OB patients (BMI = 36.6 ± 6.0; F/M = 40/6) was analyzed and compared to that of 46 NW subjects (BMI = 21.6 ± 2.1; F/M = 41/5), matched for sex, age and smoking status, by using 16S rRNA gene sequencing on MiSeq Illumina platform. The gut microbial community of OB patients exhibited a significant decrease in the relative abundance of several Bacteroidetes taxa (i.e. Flavobacteriaceae, Porphyromonadaceae, Sphingobacteriaceae, Flavobacterium, Rikenella spp., Pedobacter spp., Parabacteroides spp., Bacteroides spp.) when compared to NW; instead, several Firmicutes taxa were significantly increased in the same subjects (Lachnospiraceae, Gemellaceae, Paenibacillaceae, Streptococcaceae, Thermicanaceae, Gemella, Mitsuokella, Streptococcus, Acidaminococcus spp., Eubacterium spp., Ruminococcus spp., Megamonas spp., Streptococcus, Thermicanus, Megasphaera spp. and Veillonella spp.). Correlation analysis indicated that body fatness and waist circumference negatively correlated with Bacteroidetes taxa, while Firmicutes taxa positively correlated with body fat and negatively with muscle mass and/or physical activity level. Furthermore, the relative abundance of several bacterial taxa belonging to Enterobacteriaceae family, known to exhibit endotoxic activity, was increased in the OB group compared to NW. The results extend our knowledge on the GM profiles in Italian OB, identifying novel taxa linking obesity and intestine.


2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1560-1560
Author(s):  
Inah Gu ◽  
Wing Shun Lam ◽  
Daya Marasini ◽  
Cindi Brownmiller ◽  
Brett Savary ◽  
...  

Abstract Objectives Arabinoxylan is a non-starch polysaccharide and rich in wheat, rice and many other cereal grains. Diets high in fiber help promoting gut health in obesity. The objective of this study was to investigate the impact of arabinoxylan from rice bran on the gut microbiota and short chain fatty acids (SCFA) in normal weight (NW) and overweight/obese (OO) subjects through in vitro fecal fermentation. Methods Arabinoxylan was extracted from rice bran fiber. For in vitro fecal fermentation, each fecal sample from NW (n = 6, 3 males and 3 females) and OO (n = 7, 3 males and 4 females) was diluted into anaerobic medium with three treatments: control (no substrates), fructooligosaccharides (FOS, a well-known prebiotic), and arabinoxylan. Samples were incubated at 37˚C and aliquots were taken at 0, 4, 8, 12 and 24 h. SCFA content from samples at all timepoints was analyzed using HPLC. Samples at 0 and 24 h were used for gut microbiota analysis through 16S rRNA gene sequencing. Statistical analyses were performed for the randomized complete block design, where the weight classes are confounded with blocks (subjects). Friedman test was used to determine the difference at 5% level of significance. Results As a result, arabinoxylan treatment significantly increased total SCFA concentration in both NW and OO subjects than control (P < 0.05), comparable to FOS treatment. Between weight classes under arabinoxylan treatment, OO group showed a significantly higher total SCFA content than NW group (P < 0.05). Arabinoxylan changed gut microbial population at the genus level, stimulating Bifidobacterium, Collinsella and Blautia and decreasing Clostridium XIVa and b, Dorea and Oscillibacter (P < 0.05). In addition, different microbiome population was shown in weight classes with three treatments, showing higher Bacteroides in NW and higher Prevotella in OO. Conclusions These results showed that arabinoxylan from rice bran modified gut microbiota in both weight classes, increasing total SCFA content. This study suggests that arabinoxylan from rice bran may have a potential impact on microbial gut health in obesity with prebiotic activities. Funding Sources University of Arkansas.


2020 ◽  
Vol 33 (4) ◽  
Author(s):  
Marie-Céline Zanella ◽  
Samuel Cordey ◽  
Laurent Kaiser

SUMMARY Viral primary infections and reactivations are common complications in patients after solid organ transplantation (SOT) and hematopoietic stem cell transplantation (HSCT) and are associated with high morbidity and mortality. Among these patients, viral infections are frequently associated with viremia. Beyond the usual well-known viruses that are part of the routine clinical management of transplant recipients, numerous other viral signatures or genomes can be identified in the blood of these patients. The identification of novel viral species and variants by metagenomic next-generation sequencing has opened up a new field of investigation and new paradigms. Thus, there is a need to thoroughly describe the state of knowledge in this field with a review of all viral infections that should be scrutinized in high-risk populations. Here, we review the eukaryotic DNA and RNA viruses identified in blood, plasma, or serum samples of pediatric and adult SOT/HSCT recipients and the prevalence of their detection, with a particular focus on recently identified viruses and those for which their potential association with disease remains to be investigated, such as members of the Polyomaviridae, Anelloviridae, Flaviviridae, and Astroviridae families. Current knowledge of the clinical significance of these viral infections with associated viremia among transplant recipients is also discussed. To ensure a comprehensive description in these two populations, individuals described as healthy (mostly blood donors) are considered for comparative purposes. The list of viruses that should be on the clinicians’ radar is certainly incomplete and will expand, but the challenge is to identify those of possible clinical significance.


2020 ◽  
Vol 52 (12) ◽  
pp. 1959-1975
Author(s):  
Yu Wang ◽  
Weifan Yao ◽  
Bo Li ◽  
Shiyun Qian ◽  
Binbin Wei ◽  
...  

AbstractGut microbiota dysbiosis has a significant role in the pathogenesis of metabolic diseases, including obesity. Nuciferine (NUC) is a main bioactive component in the lotus leaf that has been used as food in China since ancient times. Here, we examined whether the anti-obesity effects of NUC are related to modulations in the gut microbiota. Using an obese rat model fed a HFD for 8 weeks, we show that NUC supplementation of HFD rats prevents weight gain, reduces fat accumulation, and ameliorates lipid metabolic disorders. Furthermore, 16S rRNA gene sequencing of the fecal microbiota suggested that NUC changed the diversity and composition of the gut microbiota in HFD-fed rats. In particular, NUC decreased the ratio of the phyla Firmicutes/Bacteroidetes, the relative abundance of the LPS-producing genus Desulfovibrio and bacteria involved in lipid metabolism, whereas it increased the relative abundance of SCFA-producing bacteria in HFD-fed rats. Predicted functional analysis of microbial communities showed that NUC modified genes involved in LPS biosynthesis and lipid metabolism. In addition, serum metabolomics analysis revealed that NUC effectively improved HFD-induced disorders of endogenous metabolism, especially lipid metabolism. Notably, NUC promoted SCFA production and enhanced intestinal integrity, leading to lower blood endotoxemia to reduce inflammation in HFD-fed rats. Together, the anti-obesity effects of NUC may be related to modulations in the composition and potential function of gut microbiota, improvement in intestinal barrier integrity and prevention of chronic low-grade inflammation. This research may provide support for the application of NUC in the prevention and treatment of obesity.


2019 ◽  
Vol 7 (1) ◽  
pp. e000717 ◽  
Author(s):  
Minchun Zhang ◽  
Rilu Feng ◽  
Mei Yang ◽  
Cheng Qian ◽  
Zheng Wang ◽  
...  

ObjectiveRecent studies have demonstrated that gut microbiota was closely related to metabolic disorders such as type 2 diabetes. Oral antidiabetic medications including metformin, acarbose and sitagliptin lowered blood glucose levels via acting on the gastrointestinal tract. The aim of the study was to observe the comparisons among those medications on gut microbiota composition.Research design and methodsZucker diabetic fatty rats (n=32) were randomly divided into four groups, and had respectively gastric administration of normal saline (control), metformin (215.15 mg/kg/day), acarbose (32.27 mg/kg/day), or sitagliptin (10.76 mg/kg/day) for 4 weeks. Blood glucose levels were measured during an intragastric starch tolerance test after the treatments. 16S rRNA gene sequencing was used to access the microbiota in the fecal samples.ResultsMetformin, acarbose, and sitagliptin monotherapy effectively decreased fasting and postprandial blood glucose levels (p<0.001). Acarbose group displayed specific cluster and enterotype mainly composed byRuminococcus 2whileLactobacilluswas the dominant bacterium in the enterotype of the other three groups. The relative abundance of generaRuminococcus 2andBifidobacteriumwas dramatically higher in acarbose group. Metformin and sitagliptin increased the relative abundance of genus Lactobacillus. Metagenomic prediction showed that the functional profiles of carbohydrate metabolism were enriched in acarbose group.ConclusionsMetformin, acarbose and sitagliptin exerted different effects on the composition of gut microbiota and selectively increased the beneficial bacteria. Supplementation with specific probiotics may further improve the hypoglycemic effects of the antidiabetic drugs.


Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 744 ◽  
Author(s):  
Jose Jaimes ◽  
Veronika Jarosova ◽  
Ondrej Vesely ◽  
Chahrazed Mekadim ◽  
Jakub Mrazek ◽  
...  

Dietary phenolics or polyphenols are mostly metabolized by the human gut microbiota. These metabolites appear to confer the beneficial health effects attributed to phenolics. Microbial composition affects the type of metabolites produced. Reciprocally, phenolics modulate microbial composition. Understanding this relationship could be used to positively impact health by phenolic supplementation and thus create favorable colonic conditions. This study explored the effect of six stilbenoids (batatasin III, oxyresveratrol, piceatannol, pinostilbene, resveratrol, thunalbene) on the gut microbiota composition. Stilbenoids were anaerobically fermented with fecal bacteria from four donors, samples were collected at 0 and 24 h, and effects on the microbiota were assessed by 16S rRNA gene sequencing. Statistical tests identified affected microbes at three taxonomic levels. Observed microbial composition modulation by stilbenoids included a decrease in the Firmicutes to Bacteroidetes ratio, a decrease in the relative abundance of strains from the genus Clostridium, and effects on the family Lachnospiraceae. A frequently observed effect was a further decrease of the relative abundance when compared to the control. An opposite effect to the control was observed for Faecalibacterium prausnitzii, whose relative abundance increased. Observed effects were more frequently attributed to resveratrol and piceatannol, followed by thunalbene and batatasin III.


2017 ◽  
Vol 63 (11) ◽  
pp. 1685-1694 ◽  
Author(s):  
Andrew Y Koh

Abstract BACKGROUND Gut microbiota, the collective community of microorganisms inhabiting the intestine, have been shown to provide many beneficial functions for the host. Recent advances in next-generation sequencing and advanced molecular biology approaches have allowed researchers to identify gut microbiota signatures associated with disease processes and, in some cases, establish causality and elucidate underlying mechanisms. CONTENT This report reviews 3 commonly used methods for studying the gut microbiota and microbiome (the collective genomes of the gut microorganisms): 16S rRNA gene sequencing, bacterial group or species-specific quantitative polymerase chain reaction (qPCR), and metagenomic shotgun sequencing (MSS). The technical approaches and resources needed for each approach are outlined, and advantages and disadvantages for each approach are summarized. The findings regarding the role of the gut microbiota in the health of patients with cancer and stem cell transplant (SCT) patients (specifically in modulating the development of gut-derived bacterial infections and a posttransplant immune-mediated complication known as graft-vs-host-disease) are reviewed. Finally, there is discussion of the potential viability of these approaches in the actual clinical treatment of cancer and SCT patients. SUMMARY Advances in next-generation sequencing have revolutionized our understanding of the importance of the gut microbiome to human health. Both 16S rRNA gene sequencing and MSS are currently too labor-intensive or computationally burdensome to incorporate into real-time clinical monitoring of gut microbiomes. Yet, the lessons learned from these technologies could be adapted to currently used methods (e.g., qPCR) that could then be rigorously tested in the clinical care of these patients.


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