Probiotics and Psychobiotics: the Role of Microbial Neurochemicals

Probiotics and Antimicrobial Proteins - In light of recent data, microorganisms should be construed as organisms that are capable of communication and collective behaviors. Microbial communication...     

ipso-Hydroxylation and Subsequent Fragmentation: a Novel Microbial Strategy To Eliminate Sulfonamide Antibiotics

Sulfonamide antibiotics have a wide application range in human and veterinary medicine. Because they tend to persist in the environment, they pose potential problems with regard to the propagation of antibiotic resistance. Here, we identified metabolites formed during the degradation of sulfamethoxazole and other sulfonamides in Microbacterium sp. strain BR1. Our experiments showed that the degradation proceeded along an unusual pathway initiated by ipso-hydroxylation with subsequent fragmentation of the parent compound. The NADH-dependent hydroxylation of the carbon atom attached to the sulfonyl group resulted in the release of sulfite, 3-amino-5-methylisoxazole, and benzoquinone-imine. The latter was concomitantly transformed to 4-aminophenol. Sulfadiazine, sulfamethizole, sulfamethazine, sulfadimethoxine, 4-amino-N-phenylbenzenesulfonamide, and N-(4-aminophenyl)sulfonylcarbamic acid methyl ester (asulam) were transformed accordingly. Therefore, ipso-hydroxylation with subsequent fragmentation must be considered the underlying mechanism; this could also occur in the same or in a similar way in other studies, where biotransformation of sulfonamides bearing an amino group in the para-position to the sulfonyl substituent was observed to yield products corresponding to the stable metabolites observed by us.     

宏蛋白质组学:研究微生物群落的一种新策略

宏蛋白质组学是一种运用蛋白质组技术对特定微生物群落所产生的全部蛋白质进行大规模研究与分析的新技术。简要概述宏蛋白组学的产生、研究策略及其应用情况,并对其应用前景进行展望。     

Role of Probiotics in Pediatric Patients with Helicobacter pylori Infection: A Comprehensive Review of the Literature

Background: The current guidelines suggest the use of triple therapy as first choice treatment of Helicobacter pylori infection, although the eradication failure rate is more than 30%. Current interest in probiotics as therapeutic agents against H. pylori is stimulated not only by the clinical data showing efficacy of some probiotics in different gastrointestinal diseases but also by the increasing resistance of pathogenic bacteria to antibiotics, thus the interest for alternative therapies is a real actual topic. Aim: To review in vitro and in vivo studies on the role of probiotics in H. pylori infection focusing on the paediatric literature. Materials and methods: Pre‐clinical and clinical paediatric studies in English assessing the role of probiotics in H. pylori infection identified by MEDLINE search (1950–2009) were reviewed. Results: In vitro studies demonstrated an inhibitory activity of probiotics on H. pylori growth and that this effect is extremely strain specific. Available data in children indicate that probiotics seems to be efficacious for the prevention of antibiotic associated side‐effects, and might be of help for the prevention of H. pylori complications by decreasing H. pylori density and gastritis, and for the prevention of H. pylori colonization or re‐infection by inhibiting adhesion to gastric epithelial cells. There is no clear evidence that probiotics may increase the H. pylori eradication rate. Conclusion: Both in vitro and in vivo studies provide evidence that probiotics may represent a novel approach to the management of H. pylori infection.     

Updating the Role of Probiotics,Prebiotics, and Synbiotics for Tilapia Aquaculture as Leading Candidates for Food Sustainability: a Review

Probiotics and Antimicrobial Proteins - Tilapia production has significantly increased over the past few years due to the adoption of semi-intensive and intensive aquaculture technologies. However,...     

Using a Mathematical Model to Analyze the Role of Probiotics and Inflammation in Necrotizing Enterocolitis

Background

Necrotizing enterocolitis (NEC) is a severe disease of the gastrointestinal tract of pre-term babies and is thought to be related to the physiological immaturity of the intestine and altered levels of normal flora in the gut. Understanding the factors that contribute to the pathology of NEC may lead to the development of treatment strategies aimed at re-establishing the integrity of the epithelial wall and preventing the propagation of inflammation in NEC. Several studies have shown a reduced incidence and severity of NEC in neonates treated with probiotics (beneficial bacteria species).

Methodology/Principal Findings

The objective of this study is to use a mathematical model to predict the conditions under which probiotics may be successful in promoting the health of infants suffering from NEC. An ordinary differential equation model is developed that tracks the populations of pathogenic and probiotic bacteria in the intestinal lumen and in the blood/tissue region. The permeability of the intestinal epithelial layer is treated as a variable, and the role of the inflammatory response is included. The model predicts that in the presence of probiotics health is restored in many cases that would have been otherwise pathogenic. The timing of probiotic administration is also shown to determine whether or not health is restored. Finally, the model predicts that probiotics may be harmful to the NEC patient under very specific conditions, perhaps explaining the detrimental effects of probiotics observed in some clinical studies.

Conclusions/Significance

The reduced, experimentally motivated mathematical model that we have developed suggests how a certain general set of characteristics of probiotics can lead to beneficial or detrimental outcomes for infants suffering from NEC, depending on the influences of probiotics on defined features of the inflammatory response.     

The Effect of Probiotics on Halitosis: a Systematic Review and Meta-analysis

Probiotics and Antimicrobial Proteins - Although several studies have evaluated the inhibitory effect of probiotics on halitosis, findings are inconsistent. This systematic review and meta-analysis...     

Probiotics tailored to the infant: a window of opportunity

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The Role of Probiotics in the Treatment of Dysentery: a Randomized Double-Blind Clinical Trial

Diarrhea is considered as an important cause of morbidity and mortality, even though one of the main reasons of death following diarrhea is initiated by dysentery. In recent years, the consumption of probiotics has been proposed for the treatment of infectious diarrhea. Despite most of the studies on probiotics have focused on acute watery diarrhea, few studies in the field of dysentery have found beneficial effects of probiotics. This study is a randomized double-blind clinical trial. The patients were randomly placed into control and case groups. In the intervention group, the patients received probiotics in the form of Kidilact® sachet, which contained high amounts of 7-strain friendly bacteria strains of Lactobacillus casei, Lactobacillus acidophilus, Lactobacillus rhamnosus, Lactobacillus bulgaricus, Bifidobacterium infantis, Bifidobacterium breve, and Streptococcus thermophiles. On the other hand, the patients in the control group received placebo sachets on a daily basis for 5 days. It is notable that the treatment protocol of acute dysentery was done on both groups. The results of this study showed significant differences in the duration of blood in diarrhea between probiotic consumers (2.62 days) and the control group (3.16 days) (P value = 0.05). Additionally, significant differences in the average length of hospitalization in probiotic consumers (3.16 days) and control (3.66 days), (P value = 0.02) could be claimed that the consumption of probiotics is effective in reducing the duration of dysentery and diarrhea. The results of this study suggest that the use of probiotics can be effective in reducing the duration of blood in diarrhea. This study was also recorded in the Iran center of clinical trials registration database (IRCT2014060617985N1).     

Liposome‐Bilirubin Interaction: A Novel Strategy to Eliminate Bilirubin from Systemic Circulation

In the present study, we established the role of liposomes in removal of bilirubin from systemic circulation of the hyperbilirubinemic rats. Bilirubin has been demonstrated to possess inherent tendency to interact with liposomes through ionic as well as hydrophobic interactions. The size as well as lamellarity of the liposomes does not seem to affect their binding with bilirubin. However, the charge on the surface of liposomes plays an important role in bilirubin‐liposome interaction, e.g., bilirubin binds more extensively with positively charged liposomes as compared to the neutral or negatively charged liposomes. The present study further demonstrates that liposomes were effective in reducing the increased plasma bilirubin level in hyperbilirubinemic model animals as well. The results of the study suggest that positively charged liposome‐mediated selective homing of excess plasma bilirubin to the hepatocytes seems to offer an important strategy in management of hyperbilirubinemic conditions.     

Role of Probiotics in Oral Health Maintenance Among Patients Undergoing Fixed Orthodontic Therapy: a Systematic Review of Randomized Controlled Clinical Trials

The aim was to assess the role of probiotics in oral health maintenance among patients undergoing fixed orthodontic therapy (OT). An unrestricted search of indexed databases was performed until April 2020 using the following Mesh-terms: (1) probiotic and (2) orthodontic. Randomized controlled clinical trials (RCTs) evaluating the influence of probiotic therapy (PT) towards oral health maintenance/improvement in patients undergoing fixed OT were included. Data screening, selection, and extraction were performed; and the risk of bias was assessed using the Cochrane Collaboration’s tool. All evaluations were performed by 2 independent researchers; and disagreements were resolved via discussion. Nine RCTs were included. Eight studies reported that PT improves oral health in patients undergoing fixed OT. Seven studies showed that PT reduces the counts of oral pathogenic bacteria in the oral biofilm and/or saliva. One study reported that PT reduces halitosis in patients undergoing fixed OT. One study found that PT reduces the scores of plaque index (PI) and gingival index (GI); and one study reported that PT has no significant influence on PI and GI in patients undergoing fixed OT. One study reported that PT does not prevent the formation of white spot lesions during fixed OT. Three and 6 studies had a moderate and low risk of bias, respectively. A power analysis was performed in 4 studies. In conclusion, probiotics exhibit antimicrobial activity against oral pathogenic bacteria; however, due to the limitations of the studies assessed, further well-designed RCTs are needed.

     

益生菌抗衰老作用机制研究进展

衰老会引起机体诸多不良的生理变化并增加对疾病的易感性,明确引发衰老的机制对于寻找其干预措施至关重要。研究发现,自由基氧化应激、炎症性衰老、免疫衰老、肠道菌群失调是引发衰老的相关机制。益生菌被报道具有潜在的延缓衰老作用,比较分析了常用益生菌抗衰老评价模型,并从衰老引发机制出发,重点综述了益生菌对肠道菌群的调节机制和抗衰老相关信号通路的影响,旨为进一步研究益生菌抗衰老作用提供新思路。     

Characterizing the Aedes aegypti Population in a Vietnamese Village in Preparation for a Wolbachia-Based Mosquito Control Strategy to Eliminate Dengue

Background

A life-shortening strain of the obligate intracellular bacteria Wolbachia, called wMelPop, is seen as a promising new tool for the control of Aedes aegypti. However, developing a vector control strategy based on the release of mosquitoes transinfected with wMelPop requires detailed knowledge of the demographics of the target population.

Methodology/Principal Findings

In Tri Nguyen village (611 households) on Hon Mieu Island in central Vietnam, we conducted nine quantitative entomologic surveys over 14 months to determine if Ae. aegypti populations were spatially and temporally homogenous, and to estimate population size. There was no obvious relationship between mosquito (larval, pupal or adult) abundance and temperature and rainfall, and no area of the village supported consistently high numbers of mosquitoes. In almost all surveys, key premises produced high numbers of Ae. aegypti. However, these premises were not consistent between surveys. For an intervention based on a single release of wMelPop-infected Ae. aegypti, release ratios of infected to uninfected adult mosquitoes of all age classes are estimated to be 1.8–6.7∶1 for gravid females (and similarly aged males) or teneral adults, respectively. We calculated that adult female mosquito abundance in Tri Nguyen village could range from 1.1 to 43.3 individuals of all age classes per house. Thus, an intervention could require the release of 2–78 wMelPop-infected gravid females and similarly aged males per house, or 7–290 infected teneral female and male mosquitoes per house.

Conclusions/Significance

Given the variability we encountered, this study highlights the importance of multiple entomologic surveys when evaluating the spatial structure of a vector population or estimating population size. If a single release of wMelPop-infected Ae. aegypti were to occur when wild Ae. aegypti abundance was at its maximum, a preintervention control program would be necessary to ensure that there was no net increase in mosquito numbers. However, because of the short-term temporal heterogeneity, the inconsistent spatial structure and the impact of transient key premises that we observed, the feasibility of multiple releases of smaller numbers of mosquitoes also needs to be considered. In either case, fewer wMelPop-infected mosquitoes would then need to be released, which will likely be more acceptable to householders.     

Review: Microbial synthesis of agrochemical metabolites

The synthesis of agrochemical metabolite reference standards by microbial cultures can serve as a useful alternative to conventional chemical synthesis, particularly when the chemical synthesis is difficult. Microbially generated metabolites of agrochemicals can also be useful for predicting degradative pathways in animals, plants and soils prior to conducting animal, plant and soil metabolism studies which are required by regulatory agencies to support agrochemical registrations. Examples from the literature are used to illustrate the utility of synthesizing metabolites of agrochemicals by common microbes. Received 17 January 1997/ Accepted in revised form 20 March 1997     

Review: Microbial colonization of prosthetic devices

Conclusion The threat of bacterial colonization and biofilm formation poses the most important limitation on the use and development of prosthetic devices in human medicine. Data from the literature suggest that microbial adherence effected by the glycocalyx is a fundamental factor in sepsis involving biomaterials and that it may explain the resistance of such infections to host defense mechanisms and to antibiotherapy. A full appreciation of the existence and the consequences of the biofilm mode of bacterial growth is required so that we can both prevent and eliminate these protected microbial reservoirs.     

外泌体：探究微生物感染机制的新视角

外泌体是细胞外囊泡的一种,由多囊泡体和细胞膜融合后释放到细胞外。外泌体能递送有功能的分子,包括蛋白质、脂质和核酸给受体细胞,参与细胞间通讯,影响细胞的各种生理与病理功能。近年来,越来越多研究发现,外泌体在病原微生物感染性疾病发病机制中也发挥重要作用。在慢性感染中,外泌体能传播感染性蛋白质和病毒RNA,并改变未感染细胞的功能。同时,这些具有极强免疫原性的蛋白质可向免疫系统递送病原信息,激活免疫系统。本文就外泌体在慢性病原体感染中的相关研究进展进行综述。研究这些机制,可为慢性感染的诊断和治疗提供新的思路。