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Chemosphere May 2021This paper review is aiming to comprehensively identify and appraise the current available knowledge on microbial composition and microbial dynamics in anaerobic... (Review)
Review
This paper review is aiming to comprehensively identify and appraise the current available knowledge on microbial composition and microbial dynamics in anaerobic digestion with focus on the interconnections between operational parameters and microbial community. We systematically searched Scopus, Web of Science, pubmed and Embase (up to August 2019) with relative keywords to identify English-language studies published in peer-reviewed journals. The data and information on anaerobic reactor configurations, operational parameters such as pretreatment methods, temperature, trace elements, ammonia, organic loading rate, and feedstock composition and their association with the microbial community and microbial dynamics were extracted from eligible articles. Of 306 potential articles, 112 studies met the present review objectives and inclusion criteria. The results indicated that both aceticlastic and hydrogenotrophic methanogenesis are dominant in anaerobic digesters and their relative composition is depending on environmental conditions. However, hydrogenotrophic methanogens are more often observed in extreme conditions due to their higher robustness compared to aceticlastic methangoens. Firmicutes and Bacteroidetes phyla are most common fermentative bacteria of the acidogenic phase. These bacteria secrete lytic enzymes to degrade organic matters and are able to survive in extreme conditions and environments due to their spores. In addition, among archaea Methanosaeta, Methanobacterium, and Methanosarcinaceae are found at high relative abundance in anaerobic digesters operated with different operational parameters. Overall, understanding the shifts in microbial composition and diversity as results of operational parameters variation in anaerobic digestion process would improve the stability and process performance.
Topics: Anaerobiosis; Archaea; Bioreactors; Methane; Microbiota
PubMed: 33121817
DOI: 10.1016/j.chemosphere.2020.128618 -
Journal of Prosthodontics : Official... Mar 2021To evaluate and synthesize the existing evidence on the microbiological and human immune response associated with peri-implantitis in comparison to healthy implants. (Review)
Review
PURPOSE
To evaluate and synthesize the existing evidence on the microbiological and human immune response associated with peri-implantitis in comparison to healthy implants.
MATERIALS AND METHODS
Three electronic databases (MEDLINE, Embase, and Cochrane Library) were searched in October 2019 to identify clinical studies evaluating the microbiota and the immune response associated with peri-implantitis. Two reviewers independently screened the studies and used the full text to extract the data. A qualitative synthesis was performed on the extracted data and summary tables were prepared. Due to clinical and methodological heterogeneity among included studies, no meta-analysis was performed.
RESULTS
Forty studies were included in this review. Of these, 20 studies compared the microbiological profile of peri-implantitis with healthy implants. Nineteen studies focused on the immune response associated with peri-implantitis in comparison to healthy implants. Three studies focus on gene polymorphism associated with peri-implantitis. The most commonly reported bacteria associated with peri-implantitis were obligate anaerobe Gram-negative bacteria (OAGNB), asaccharolytic anaerobic Gram-positive rods (AAGPRs), and other Gram-positive species. In regard to immune response, the most frequently reported pro-inflammatory mediators associated with peri-implantitis were IL-1β, IL-6, IL-17, TNF-α. Osteolytic mediator, e.g., RANK, RANKL, Wnt5a and proteinase enzymes, MMP-2, MMP-9, and Cathepsin-K were also expressed at higher level in peri-implantitis sites compared to control.
CONCLUSIONS
Peri-implantitis is associated with complex and different microbiota than healthy implants including bacteria, archaea, fungi, and virus. This difference in the microbiota could provoke higher inflammatory response and osteolytic activity. All of this could contribute to the physiopathology of peri-implantitis.
Topics: Dental Implants; Humans; Immunity; Microbiota; Peri-Implantitis
PubMed: 33016381
DOI: 10.1111/jopr.13270 -
Vaccines Aug 2020Ruminants produce considerable amounts of methane during their digestive process, which makes the livestock industry as one of the largest sources of anthropogenic... (Review)
Review
Ruminants produce considerable amounts of methane during their digestive process, which makes the livestock industry as one of the largest sources of anthropogenic greenhouse gases. To tackle this situation, several solutions have been proposed, including vaccination of ruminants against microorganisms responsible for methane synthesis in the rumen. In this review, we summarize the research done on this topic and describe the state of the art of this strategy. The different steps implied in this approach are described: experimental design, animal model (species, age), antigen (whole cells, cell parts, recombinant proteins, peptides), adjuvant (Freund's, Montanide, saponin, among others), vaccination schedule (booster intervals and numbers) and measurements of treatment success (immunoglobulin titers and/or effects on methanogens and methane production). Highlighting both the advances made and knowledge gaps in the use of vaccines to inhibit ruminant methanogen activity, this research review opens the door to future studies. This will enable improvements in the methodology and systemic approaches so as to ensure the success of this proposal for the sustainable mitigation of methane emission.
PubMed: 32825375
DOI: 10.3390/vaccines8030460 -
International Journal of Sports Medicine Oct 2020Growing evidence shows the contribution of physical activity interventions to the gut microbiome. However, specific physical activity characteristics that can modify the...
Growing evidence shows the contribution of physical activity interventions to the gut microbiome. However, specific physical activity characteristics that can modify the gut microbiome are unknown. This review's aim was to explore the contribution of physical activity intervention characteristics on human gut microbiome composition, in terms of diversity, specific bacterial groups, and associated gut microbiome metabolites. A literature search in PubMed; Cochrane Library; CINAHL-EBSCO; SCOPUS; Web of Science; ClinicalTrials.gov; PROSPERO; and ProQuest. Five studies met the inclusion criteria of a physical activity intervention duration of at least five weeks, with any description of the type or dose used. All included studies reported an endurance training; two studies used endurance and an additional muscle-strengthening training regimen. All studies reported using a dietary intervention control. Reported gut microbiome α-diversity changes were non-significant, β-diversity changes were mixed (three studies reported an increase, two reported non-significant changes). All studies reported significant changes in the abundances of specific bacterial/archaea groups and bacteria-related metabolites following interventions. In conclusion, physical activity (regardless of specific characteristics) has significant contribution to gut microbiome composition and associated metabolites. There are no current recommendations for physical activity to promote gut microbiome composition. Future studies should focus on the contribution of current recommended physical activity dose to gut microbiome composition.
Topics: Adult; Age Factors; Body Mass Index; Diet; Exercise; Gastrointestinal Microbiome; Humans; Inflammation; Physical Conditioning, Human; Physical Endurance; Physical Fitness; Resistance Training; Sedentary Behavior
PubMed: 32455454
DOI: 10.1055/a-1157-9257 -
Future Microbiology May 2019Breastfeeding is a major determinant of human health. Breast milk is not sterile and ecological large-scale sequencing methods have revealed an unsuspected microbial...
Breastfeeding is a major determinant of human health. Breast milk is not sterile and ecological large-scale sequencing methods have revealed an unsuspected microbial diversity that plays an important role. However, microbiological analysis at the species level has been neglected while it is a prerequisite before understanding which microbe is associated with symbiosis or dysbiosis, and health or disease. We review the currently known bacterial repertoire from the human breast and milk microbiota using a semiautomated strategy. Total 242 articles from 38 countries, 11,124 women and 15,489 samples were included. Total 820 species were identified mainly composed of Proteobacteria and Firmicutes. We report variations according to the analytical method (culture or molecular method), the anatomical site (breast, colostrum or milk) and the infectious status (healthy control, mastitis, breast abscess, neonatal infection). In addition, we compared it with the other human repertoires. Finally, we discuss its putative origin and role in health and disease.
Topics: Abscess; Archaea; Bacteria; Breast; Breast Feeding; Colostrum; Databases, Factual; Dysbiosis; Female; Humans; Mastitis; Microbiota; Milk, Human; Symbiosis
PubMed: 31025880
DOI: 10.2217/fmb-2018-0317 -
Journal of Dental Research Sep 2014There is substantial evidence supporting the role of certain oral bacteria species in the onset and progression of periodontitis. Nevertheless, results of... (Review)
Review
There is substantial evidence supporting the role of certain oral bacteria species in the onset and progression of periodontitis. Nevertheless, results of independent-culture diagnostic methods introduced about a decade ago have pointed to the existence of new periodontal pathogens. However, the data of these studies have not been evaluated together, which may generate some misunderstanding on the actual role of these microorganisms in the etiology of periodontitis. The aim of this systematic review was to determine the current weight of evidence for newly identified periodontal pathogens based on the results of "association" studies. This review was conducted and reported in accordance with the PRISMA statement. The MEDLINE, EMBASE, and Cochrane databases were searched up to September 2013 for studies (1) comparing microbial data of subgingival plaque samples collected from subjects with periodontitis and periodontal health and (2) evaluating at least 1 microorganism other than the already-known periodontal pathogens. From 1,450 papers identified, 41 studies were eligible. The data were extracted and registered in predefined piloted forms. The results suggested that there is moderate evidence in the literature to support the association of 17 species or phylotypes from the phyla Bacteroidetes, Candidatus Saccharibacteria, Firmicutes, Proteobacteria, Spirochaetes, and Synergistetes. The phylum Candidatus Saccharibacteria and the Archaea domain also seem to have an association with disease. These data point out the importance of previously unidentified species in the etiology of periodontitis and might guide future investigations on the actual role of these suspected new pathogens in the onset and progression of this infection.
Topics: Archaea; Bacteria; Bacteroidetes; Dental Plaque; Gram-Negative Anaerobic Bacteria; Gram-Negative Bacteria; Humans; Periodontitis; Periodontium; Phylogeny; Proteobacteria; Spirochaetales
PubMed: 25074492
DOI: 10.1177/0022034514542468