scholarly journals Lytic Bacteroides uniformis bacteriophages exhibiting host tropism congruent with diversity generating retroelement

2020 ◽  
Author(s):  
Stina Hedzet ◽  
Tomaž Accetto ◽  
Maja Rupnik
Keyword(s):  
Gut Microbiota ◽  
Outer Membrane Proteins ◽  
Marker Gene ◽  
Human Microbiome ◽  
Host Tropism ◽  
Sequence Variations ◽  
Common Marker ◽  
Evolutionary Advantage ◽  
Bacterial Groups

AbstractIntestinal phages are abundant and important component of gut microbiota, but our knowledge remains limited to only a few isolated and characterized representatives targeting numerically dominant gut bacteria. Here we describe isolation of human intestinal phages infecting Bacteroides uniformis. Bacteroides is one of the most common bacterial groups in the global human gut microbiota, however, to date not many Bacteroides specific phages are known. Phages isolated in this study belong to a novel viral genus, Bacuni, within Siphoviridae family and represent the first lytic phages, genomes of which encode diversity generating retroelements (DGR). This region is assumed to promote phage adaptation to the rapidly changing environmental conditions and to broaden its host range. Three isolated phages showed 99,83% genome identity but infected distinct B. uniformis strains. The tropism of Bacuni phages appeared to be dependent on the interplay of DGR mediated sequence variations of phage fimbrial tip proteins and mutations in host genes coding for outer-membrane proteins. We found prophages with up to 85% aa similarity to Bacuni phages in the genomes of B. acidifaciens and Prevotella sp.. Despite the abundance of Bacteroides within human microbiome, we found Bacuni phages only in a limited subset of published gut metagenomes.ImportanceThe lack of common marker gene in viruses require a precise characterization of diverse isolated phages to enhance metagenomic analyses and to understand their role in gut microbiota. Here we report the isolation of phages representing a new genus with characteristics so far not known or rarely described in intestinal phages. They are the first lytic phages specific for Bacteroides uniformis, a bacterial representative of the prevalent genus in the gut of humans and animals. Additionally, they are the first lytic phages containing specific regions (diversity generating retroelement) that putatively influence host tropism. The ability to switch constantly the targeted populations of the host species could provide an evolutionary advantage to these bacteriophages and may affect intra species diversity.

scholarly journals Novel Siphoviridae Bacteriophages Infecting Bacteroides uniformis Contain Diversity Generating Retroelement

2021 ◽  
Vol 9 (5) ◽  
pp. 892
Author(s):  
Stina Hedžet ◽  
Maja Rupnik ◽  
Tomaž Accetto
Keyword(s):  
Gut Microbiota ◽  
Outer Membrane Proteins ◽  
Human Microbiome ◽  
Human Gut ◽  
Amino Acid Similarity ◽  
Gene Encoding ◽  
Sequence Variations ◽  
Bacterial Groups ◽  
Putative Phage ◽  
Host Genes

Intestinal phages are abundant and important components of gut microbiota, yet the isolated and characterized representatives that infect abundant gut bacteria are sparse. Here we describe the isolation of human intestinal phages infecting Bacteroidesuniformis. Bacteroides is one of the most common bacterial groups in the global human gut microbiota; however, to date not many Bacteroides specific phages are known. Phages isolated in this study belong to a novel viral genus, Bacuni, within the Siphoviridae family. Their genomes encode diversity-generating retroelements (DGR), which were shown in other bacteriophages to promote phage adaptation to rapidly changing environmental conditions and to broaden their host range. Three isolated phages showed 99.83% genome identity but one of them infected a distinct B. uniformis strain. The tropism of Bacuni phages appeared to be dependent on the interplay of DGR mediated sequence variations of gene encoding putative phage fimbrial tip proteins and mutations in host genes coding for outer-membrane proteins. We found prophages with up to 85% amino acid similarity over two-thirds of the Bacuni phage genome in the B. acidifaciens and Prevotella sp. genomes. Despite the abundance of Bacteroides within the human microbiome, we found Bacuni phages only in a limited subset of published gut metagenomes.

scholarly journals Characterization of Early Life Stress-Affected Gut Microbiota

2021 ◽  
Vol 11 (7) ◽  
pp. 913
Author(s):  
Noriyoshi Usui ◽  
Hideo Matsuzaki ◽  
Shoichi Shimada
Keyword(s):  
Social Behavior ◽  
Gut Microbiota ◽  
Life Stress ◽  
Early Life ◽  
Early Life Stress ◽  
The Body ◽  
Strong Impact ◽  
And Behavior ◽  
Bacterial Groups

Early life stress (ELS), such as neglect and maltreatment, exhibits a strong impact on the mental and brain development of children. However, it is not fully understood how ELS affects the body and behavior of children. Therefore, in this study, we performed social isolation on weaned pre-adolescent mice and investigated how ELS could affect gut microbiota and mouse behavior. Using the metagenomics approach, we detected an overall ELS-related change in the gut microbiota and identified Bacteroidales and Clostridiales as significantly altered bacterial groups. These metagenomic alterations impaired social behavior in ELS mice, which also correlated with the abundance of Bacteroidales and Clostridiales. Our results demonstrate that ELS alters the gut microbiota and reduces social behavior in adolescent mice.

scholarly journals Modulation of Gut Microbiota and Oxidative Status by β-Carotene in Late Pregnant Sows

2020 ◽  
Vol 7 ◽  
Author(s):  
Xupeng Yuan ◽  
Jiahao Yan ◽  
Ruizhi Hu ◽  
Yanli Li ◽  
Ying Wang ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Dietary Supplementation ◽  
Basal Diet ◽  
Fecal Microbiota ◽  
Control Group ◽  
Metabolic Activities ◽  
The Impact ◽  
Positive Effect ◽  
Β Carotene

Recent evidences suggest that gut microbiota plays an important role in regulating physiological and metabolic activities of pregnant sows, and β-carotene has a potentially positive effect on reproduction, but the impact of β-carotene on gut microbiota in pregnant sows remains unknown. This study aimed to explore the effect and mechanisms of β-carotene on the reproductive performance of sows from the aspect of gut microbiota. A total of 48 hybrid pregnant sows (Landrace × Yorkshire) with similar parity were randomly allocated into three groups (n = 16) and fed with a basal diet or a diet containing 30 or 90 mg/kg of β-carotene from day 90 of gestation until parturition. Dietary supplementation of 30 or 90 mg/kg β-carotene increased the number of live birth to 11.82 ± 1.54 and 12.29 ± 2.09, respectively, while the control group was 11.00 ± 1.41 (P = 0.201). Moreover, β-carotene increased significantly the serum nitric oxide (NO) level and glutathione peroxidase (GSH-Px) activity (P < 0.05). Characterization of fecal microbiota revealed that 90 mg/kg β-carotene increased the diversity of the gut flora (P < 0.05). In particular, β-carotene decreased the relative abundance of Firmicutes including Lachnospiraceae AC2044 group, Lachnospiraceae NK4B4 group and Ruminococcaceae UCG-008, but enriched Proteobacteria including Bilophila and Sutterella, and Actinobacteria including Corynebacterium and Corynebacterium 1 which are related to NO synthesis. These data demonstrated that dietary supplementation of β-carotene may increase antioxidant enzyme activity and NO, an important vasodilator to promote the neonatal blood circulation, through regulating gut microbiota in sows.

scholarly journals Structural Characterization of a Polysaccharide from Gastrodia elata and Its Bioactivity on Gut Microbiota

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4443
Author(s):  
Jiangyan Huo ◽  
Min Lei ◽  
Feifei Li ◽  
Jinjun Hou ◽  
Zijia Zhang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Citric Acid ◽  
Gut Microbiota ◽  
Structural Characterization ◽  
Hot Water ◽  
Nmr Analysis ◽  
Gastrodia Elata ◽  
Hot Water Extraction ◽  
Hydroxybenzyl Alcohol

A novel homogeneous polysaccharide named GEP-1 was isolated and purified from Gastrodia elata (G. elata) by hot-water extraction, ethanol precipitation, and membrane separator. GEP-1, which has a molecular weight of 20.1 kDa, contains a polysaccharide framework comprised of only glucose. Methylation and NMR analysis showed that GEP-1 contained 1,3,6-linked-α-Glcp, 1,4-linked-α-Glcp, 1,4-linked-β-Glcp and 1,4,6-linked-α-Glcp. Interestingly, GEP-1 contained citric acid and repeating p-hydroxybenzyl alcohol as one branch. Furthermore, a bioactivity test showed that GEP-1 could significantly promote the growth of Akkermansia muciniphila (A. muciniphila) and Lacticaseibacillus paracasei (L.paracasei) strains. These results implied that GEP-1 might be useful for human by modulating gut microbiota.

scholarly journals Gut microbiota profiles and characterization of cultivable fungal isolates in IBS patients

2021 ◽  
Author(s):  
Piero Sciavilla ◽  
Francesco Strati ◽  
Monica Di Paola ◽  
Monica Modesto ◽  
Francesco Vitali ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Gut Microbiota ◽  
Healthy Subjects ◽  
Fungal Isolates ◽  
Key Points ◽  
Health Promoting ◽  
Irritable Bowel

Abstract Studies so far conducted on irritable bowel syndrome (IBS) have been focused mainly on the role of gut bacterial dysbiosis in modulating the intestinal permeability, inflammation, and motility, with consequences on the quality of life. Limited evidences showed a potential involvement of gut fungal communities. Here, the gut bacterial and fungal microbiota of a cohort of IBS patients have been characterized and compared with that of healthy subjects (HS). The IBS microbial community structure differed significantly compared to HS. In particular, we observed an enrichment of bacterial taxa involved in gut inflammation, such as Enterobacteriaceae, Streptococcus, Fusobacteria, Gemella, and Rothia, as well as depletion of health-promoting bacterial genera, such as Roseburia and Faecalibacterium. Gut microbial profiles in IBS patients differed also in accordance with constipation. Sequence analysis of the gut mycobiota showed enrichment of Saccharomycetes in IBS. Culturomics analysis of fungal isolates from feces showed enrichment of Candida spp. displaying from IBS a clonal expansion and a distinct genotypic profiles and different phenotypical features when compared to HS of Candida albicans isolates. Alongside the well-characterized gut bacterial dysbiosis in IBS, this study shed light on a yet poorly explored fungal component of the intestinal ecosystem, the gut mycobiota. Our results showed a differential fungal community in IBS compared to HS, suggesting potential for new insights on the involvement of the gut mycobiota in IBS. Key points • Comparison of gut microbiota and mycobiota between IBS and healthy subjects • Investigation of cultivable fungi in IBS and healthy subjects • Candida albicans isolates result more virulent in IBS subjects compared to healthy subjects

scholarly journals Nanopore-Sequencing Characterization of the Gut Microbiota of Melolontha melolontha Larvae: Contribution to Protection against Entomopathogenic Nematodes?

Pathogens ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 396
Author(s):  
Ewa Sajnaga ◽  
Marcin Skowronek ◽  
Agnieszka Kalwasińska ◽  
Waldemar Kazimierczak ◽  
Karolina Ferenc ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Entomopathogenic Nematodes ◽  
Bacterial Species ◽  
Antagonistic Activity ◽  
Rrna Gene ◽  
Nanopore Sequencing ◽  
Bacterial Phyla ◽  
Melolontha Melolontha

This study focused on the potential relationships between midgut microbiota of the common cockchafer Melolontha melolontha larvae and their resistance to entomopathogenic nematodes (EPN) infection. We investigated the bacterial community associated with control and unsusceptible EPN-exposed insects through nanopore sequencing of the 16S rRNA gene. Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes were the most abundant bacterial phyla within the complex and variable midgut microbiota of the wild M. melolontha larvae. The core microbiota was found to include 82 genera, which accounted for 3.4% of the total number of identified genera. The EPN-resistant larvae differed significantly from the control ones in the abundance of many genera belonging to the Actinomycetales, Rhizobiales, and Clostridiales orders. Additionally, the analysis of the microbiome networks revealed different sets of keystone midgut bacterial genera between these two groups of insects, indicating differences in the mutual interactions between bacteria. Finally, we detected Xenorhabdus and Photorhabdus as gut residents and various bacterial species exhibiting antagonistic activity against these entomopathogens. This study paves the way to further research aimed at unravelling the role of the host gut microbiota on the output of EPN infection, which may contribute to enhancement of the efficiency of nematodes used in eco-friendly pest management.

scholarly journals A novel combined approach based on HTF-Microbi.Array and qPCR for a reliable characterization of theBifidobacterium-dominated gut microbiota of breast-fed infants

2013 ◽  
Vol 343 (2) ◽  
pp. 121-126 ◽  
Author(s):  
Manuela Centanni ◽  
Silvia Turroni ◽  
Elena Biagi ◽  
Marco Severgnini ◽  
Clarissa Consolandi ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Combined Approach ◽  
Breast Fed

Gut Feeling

2016 ◽  
Vol 33 (S1) ◽  
pp. S504-S505
Author(s):  
C. Cotta ◽  
G. Jesus ◽  
V. Vila Nova ◽  
C. Moreira
Keyword(s):  
Mental Disorders ◽  
Gut Microbiota ◽  
Gut Microbiome ◽  
Bacterial Infections ◽  
Human Microbiome ◽  
Dietary Interventions ◽  
Scientific Databases ◽  
Antibiotic Drugs ◽  
Microbiome Research ◽  
Competing Interest

IntroductionThere is growing evidence of the importance of nutrition in mental disorders. Gut microbiota, influenced by environmental factors such as diet and stress, has been proposed as one of the players on a dynamic called gut-brain axis, which is thought to have an influence on behaviour and mental health.Objectives and aimsTo summarize recent evidence on the topic, and its potential role in psychiatric interventions.MethodsThe authors review updated literature collected from online scientific databases.ResultsThe development of the brain itself has been shown to be influenced by the gut microbiome. Research demonstrates that the composition of the microbiota has influence on behaviour through neuroendocrine and other neuroactive messengers production by the bacteria within the gut lumen. Studies in germ-free animals, animals exposed to bacterial infections, probiotic suplements or antibiotic drugs suggest a role for the gut microbiota in the regulation of anxiety, mood, cognition and pain. The gut microbiome has been implicated in brain disorders including anxiety and depression, multiple sclerosis, Alzheimer's disease, Parkinson's disease, and autism.ConclusionsThe treatment of mental disorders is usually based on pharmacological and psychotherapeutic interventions, and little attention is given to dietary interventions. The emerging field of research focused on the human microbiome suggests an important role for the gut microbiota in influencing brain development, behaviour and mood in humans, and points new strategies for developing novel therapeutics for mental disorders.Disclosure of interestThe authors have not supplied their declaration of competing interest.

Sign in / Sign up

Export Citation Format

Share Document