scholarly journals Human Skin Bacterial Community Response to Probiotic (Lactobacillus reuteri DSM 17938) Introduction

2020 ◽  
Vol 8 (8) ◽  
pp. 1223
Author(s):  
Marie Frerejacques ◽  
Camille Rousselle ◽  
Loüen Gauthier ◽  
Salomé Cottet-Emard ◽  
Léa Derobert ◽  
...  

The introduction of a strain or consortium has often been considered as a potential solution to restore microbial ecosystems. Extensive research on the skin microbiota has led to the development of probiotic products (with live bacterial strains) that are likely to treat dysbiosis. However, the effects of such introductions on the indigenous microbiota have not yet been investigated. Here, through a daily application of Lactobacillus reuteri DSM 17938 on volunteers’ forearm skin, we studied in vivo the impact of a probiotic on the indigenous skin bacterial community diversity using Terminal-Restriction Fragment Length Polymorphism (T-RFLP) for 3 weeks. The results demonstrate that Lactobacillus reuteri DSM 17938 inoculum had a transient effect on the indigenous community, as the resilience phenomenon was observed within the skin microbiota. Moreover, Lactobacillus reuteri DSM 17938 monitoring showed that, despite a high level of detection after 2 weeks of application, thereafter the colonization rate drops drastically. The probiotic colonization rate was correlated significantly to the effect on the indigenous microbial community structure. These preliminary results suggest that the success of probiotic use and the potential health benefits resides in the interactions with the human microbiota.

2002 ◽  
Vol 68 (9) ◽  
pp. 4390-4398 ◽  
Author(s):  
S. A. F. T. van Hijum ◽  
G. H. van Geel-Schutten ◽  
H. Rahaoui ◽  
M. J. E. C. van der Maarel ◽  
L. Dijkhuizen

ABSTRACT Fructosyltransferase (FTF) enzymes produce fructose polymers (fructans) from sucrose. Here, we report the isolation and characterization of an FTF-encoding gene from Lactobacillus reuteri strain 121. A C-terminally truncated version of the ftf gene was successfully expressed in Escherichia coli. When incubated with sucrose, the purified recombinant FTF enzyme produced large amounts of fructo-oligosaccharides (FOS) with β-(2→1)-linked fructosyl units, plus a high-molecular-weight fructan polymer (>107) with β-(2→1) linkages (an inulin). FOS, but not inulin, was found in supernatants of L. reuteri strain 121 cultures grown on medium containing sucrose. Bacterial inulin production has been reported for only Streptococcus mutans strains. FOS production has been reported for a few bacterial strains. This paper reports the first-time isolation and molecular characterization of (i) a Lactobacillus ftf gene, (ii) an inulosucrase associated with a generally regarded as safe bacterium, (iii) an FTF enzyme synthesizing both a high molecular weight inulin and FOS, and (iv) an FTF protein containing a cell wall-anchoring LPXTG motif. The biological relevance and potential health benefits of an inulosucrase associated with an L. reuteri strain remain to be established.


2012 ◽  
Vol 3 (2) ◽  
pp. 137-144 ◽  
Author(s):  
F. Vieira de Souza ◽  
R. Roque ◽  
J.L. Silva Moreira ◽  
M. Resende de Souza ◽  
J.R. Nicoli ◽  
...  

The aim of this study was to assess the potential horizontal transfer of genetic traits for antibiotic resistance between lactobacilli isolated from the chicken gut, both in vitro and in vivo. Thirty-seven Lactobacillus spp. strains isolated from the gizzard, small and large intestines and caeca of free-range broiler chickens showed multi-drug resistance as assessed by disc diffusion assays. The minimum inhibitory concentration (MIC) for vancomycin, tetracycline, erythromycin and chloramphenicol was determined in De Man, Rogosa and Sharpe broth in a microplate assay. Almost all the lactobacilli isolates were resistant to vancomycin (except strains belonging to the Lactobacillus acidophilus group) and to tetracycline (MIC≥128 μg/ml). Only five strains were resistant to erythromycin, and six to chloramphenicol. The transfer rate in filter mating experiments performed using L. acidophilus strain 4M14E (EmR), Lactobacillus vaginalis strain 5M14E (CmR), Lactobacillus salivarius strain 5C14C (EmR), and the 4G14L and 3C14C strains of Lactobacillus reuteri (CmR) showed a frequency of approximately 1×104 cfu/ml of double-resistant transconjugants for the different combinations. The exception was the L. salivarius 5C14C (EmR) and L. vaginalis 5M14E (CmR) mating combination, which produced no transconjugants. In vivo experiments performed in gnotobiotic mice by mating L. acidophilus 4M14E (EmR) with L. reuteri 3C14C (CmR), L. reuteri 4G14L (CmR) or L. vaginalis 5M14E (CmR) resulted in transconjugants at 3.95±0.29, 3.16±0.33, and 4.55±1.52 log10 cfu/g of faeces, respectively. Taken together, these data suggest that genetic exchange may occur between native bacterial strains within the gastrointestinal tract of chickens, which might maintain a dynamic gene pool conferring antibiotic resistance upon indigenous microbiota components, even in the absence of the pathogens. This possibility must be taken into account as a complementary criterion when lactobacilli are screened for probiotic use.


2000 ◽  
Vol 66 (3) ◽  
pp. 956-965 ◽  
Author(s):  
Jang-Cheon Cho ◽  
Sang-Jong Kim

ABSTRACT Despite intensive studies of microbial-community diversity, the questions of which kinds of microbial populations are associated with changes in community diversity have not yet been fully solved by molecular approaches. In this study, to investigate the impact of livestock wastewater on changes in the bacterial communities in groundwater, bacterial communities in subsurface aquifers were analyzed by characterizing their 16S rDNA sequences. The similarity coefficients of restriction fragment length polymorphism (RFLP) patterns of the cloned 16S ribosomal DNAs showed that the bacterial communities in livestock wastewater samples were more closely related to those in contaminated aquifer samples. In addition, calculations of community diversity clearly showed that bacterial communities in the livestock wastewater and the contaminated aquifer were much more diverse than those in the uncontaminated aquifer. Thus, the increase in bacterial-community diversity in the contaminated aquifer was assumed to be due to the infiltration of livestock wastewater, containing high concentrations of diverse microbial flora, into the aquifer. Phylogenetic analysis of the sequences from a subset of the RFLP patterns showed that the Cytophaga-Flexibacter-Bacteroidesand low-G+C gram-positive groups originating from livestock wastewater were responsible for the change in the bacterial community in groundwater. This was evidenced by the occurrence of rumen-related sequences not only in the livestock wastewater samples but also in the contaminated-groundwater samples. Rumen-related sequences, therefore, can be used as indicator sequences for fecal contamination of groundwater, particularly from livestock.


2021 ◽  
Author(s):  
Lisa Miclotte ◽  
Ellen De Paepe ◽  
Qiqiong Li ◽  
Andreja Rajkovic ◽  
John Van Camp ◽  
...  

In the context of the potential health hazards related to food processing, dietary emulsifiers have been shown to alter the structure and function of the gut microbial community, both in vivo and in vitro. In mouse models, these emulsifier exposed gut microbiota were shown to contribute to gut inflammation. Several knowledge gaps remain to be addressed though. As such, the impact from a longer timeframe of exposure on the gut microbiota is not known and interindividual variability in microbiome response needs to be measured. To answer these research questions, in this study the faecal microbiota from two individuals, previously selected for high and low emulsifier sensitivity, were exposed to two concentrations of soy lecithin during a 7 day treatment phase in the dynamic mucosal simulator of the human intestinal microbial ecosystem (M-SHIME). The results showed mild effects from soy lecithin on the composition and functionality of these microbial communities, which depended on the original microbial composition. The effects also mostly levelled off after 3 days of exposure. The emulsifier sensitivity for which the microbiota were selected, was preserved. Some potentially concerning effects were also registered: butyrate levels, positively correlating with Faecalibacterium abundance, were lowered by soy lecithin. Also the abundance of the beneficial Bifidobacterium genus was lowered, while the abundance of the notorious unclassified Enterobacteriaceae was increased. Within the family of the unclassified Lachnospiraceae, several genera were either suppressed or stimulated. The effects that these microbial alterations would have on a living host is not yet certain, especially given the fact that large fractions of soy lecithins constituents can be absorbed. Nevertheless, choline and phosphatidylcholine, both primary and absorbable constituents of soy lecithin, have recently been linked to cardiovascular disease via the generation of TMA by the gut microbiota. Further studies that validate our findings and link them to potential health outcomes are thus justified.


2020 ◽  
Vol 15 (1) ◽  
pp. 304-317 ◽  
Author(s):  
Camille S. Delavaux ◽  
Josh L. Schemanski ◽  
Geoffrey L. House ◽  
Alice G. Tipton ◽  
Benjamin Sikes ◽  
...  

AbstractSoil-borne pathogens structure plant communities, shaping their diversity, and through these effects may mediate plant responses to climate change and disturbance. Little is known, however, about the environmental determinants of plant pathogen communities. Therefore, we explored the impact of climate gradients and anthropogenic disturbance on root-associated pathogens in grasslands. We examined the community structure of two pathogenic groups—fungal pathogens and oomycetes—in undisturbed and anthropogenically disturbed grasslands across a natural precipitation and temperature gradient in the Midwestern USA. In undisturbed grasslands, precipitation and temperature gradients were important predictors of pathogen community richness and composition. Oomycete richness increased with precipitation, while fungal pathogen richness depended on an interaction of precipitation and temperature, with precipitation increasing richness most with higher temperatures. Disturbance altered plant pathogen composition and precipitation and temperature had a reduced effect on pathogen richness and composition in disturbed grasslands. Because pathogens can mediate plant community diversity and structure, the sensitivity of pathogens to disturbance and climate suggests that degradation of the pathogen community may mediate loss, or limit restoration of, native plant diversity in disturbed grasslands, and may modify plant community response to climate change.


2020 ◽  
Author(s):  
Ying Zhang ◽  
Anna Hu ◽  
Jianuan Zhou ◽  
Wenfei Zhang ◽  
Peng Li

Abstract Background: Ralstonia solanacearum is one of the most notorious soil-borne phytopathogens. It causes a severe wilt disease with deadly effects on many economically important crops. The microbita of disease-suppressive soils are thought that they can contribute to the disease resistance of crop plants, thus, to conduct the microbial community and their interaction characteristics between suppressive soil (SS) and conducive soil (CS) will help to understand resistance mechanism. Here, the bacterial community structure, correlation analysis with soil chemical properties, interaction network of SS (nearly no disease in three years), and CS (suffered heavy bacterial wilt disease) were analyzed. Results: Compared with CS, a higher bacterial community diversity index was found in SS , and the relative abundance of main genera Bacillus , Gaiellales , Roseiflexus , Gemmatimonadaceae , Nocardioides , and Anaerolineacear reached significant levels. Redundancy analysis at the genus level indicated that the available phosphate played a key role in the bacterial community distribution, and its role was negatively correlated with soil pH, organic matter content, alkali-hydrolyzable nitrogen, and available potassium contents. Interaction network analysis further demonstrated that greater diversity at the genus level existed in the SS network and formed a stable network. Additionally, the species of Mycobacterium , Cyanobacteria , and Rhodobiaceae are the key components that sustain the network stability. Seven clusters of orthologous groups exhibited significant differences between SS and CS. Moreover, 55 bacterial strains with distinct antagonistic activities to R. solancearum were isolated and identified. Conclusions: Our findings indicate that the bacterial diversity and interaction network differed between the CS and SS samples, providing a good foundation in the study of bacterial wilt.


2020 ◽  
Author(s):  
Ying Zhang ◽  
Anna Hu ◽  
Jianuan Zhou ◽  
Wenfei Zhang ◽  
Peng Li

Abstract BackgroundRalstonia solanacearum is one of the most notorious soil-born phytopathogen that causes a severe wilt disease with deadly effects on many economically important crops. The microbial community structure and interactions are commonly changed between bacterial wilt susceptible soil and healthy soil. Here, the bacterial community structure, correlation analysis with soil chemical properties, interaction network of healthy soil (HS, nearly no disease happened at recent three years) and diseased soil (DS, suffered heavy bacterial wilt disease) were analyzed.ResultsCompared to DS, a higher bacterial community diversity index was found in HS, and the relative abundance of main genera Bacillus, Gaiellales, Roseiflexus, Gemmatimonadaceae, Nocardioides and Anaerolineacear reached significant level. Redundancy analysis on genus level indicated that rapid available phosphate played key role on bacterial community distribution difference, and showed negative correlation with the other four chemical properties. Interaction network analysis further demonstrated that the higher genus community diversity and more extensive interactions were existed in HS network and formed stable network, and the genera Mycobacterium, Cyanobacteria and Rhodobiaceae should be the key components that sustain the network stably. Seven clusters of orthologous groups reached significant level difference between HS and DS. Moreover, 55 bacterial strains with distinct antagonistic activities to R. solancearum were isolated and identified. ConclusionsIn summary, our findings indicate that the bacterial diversity and interaction network changed between the HS and DS samples, which are also provide a good research basis for future biological control to the bacterial wilt.


PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0247309
Author(s):  
Juan Song ◽  
LiJing Min ◽  
JunRong Wu ◽  
Qingfang He ◽  
FengMao Chen ◽  
...  

Phosphate-solubilizing bacteria (PSB) have beneficial effects on plant health and soil composition. To date, studies of PSB in soil have largely been performed under field or greenhouse conditions. However, less is known about the impact of introducing indigenous PSB in the field, including their effects on the local microbial community. In this study, we conducted greenhouse and field experiments to explore the effects of the addition of indigenous PSB on the growth of Chenmou elm (Ulmus chenmoui) and on the diversity and composition of the bacterial community in the soil. We obtained four bacterial isolates with the highest phosphate-solubilizing activity: UC_1 (Pseudomonas sp.), UC_M (Klebsiella sp.), UC_J (Burkholderia sp.), and UC_3 (Chryseobacterium sp.). Sequencing on the Illumina MiSeq platform showed that the inoculated PSB did not become the dominant strains in the U. chenmoui rhizosphere. However, the soil bacterial community structure was altered by the addition of these PSB. The relative abundance of Chloroflexi decreased significantly in response to PSB application in all treatment groups, whereas the populations of several bacteria, including Proteobacteria and Bacteroidetes, increased. Network analysis indicated that Chloroflexi was the most strongly negatively correlated with Proteobacteria, whereas Proteobacteria was strongly positively correlated with Bacteroidetes. Our findings indicate that inoculation with PSB (UC_1, UC_M, UC_J, and UC_3) can improve the growth of U. chenmoui and regulate its rhizosphere microbial community. Therefore, inoculation with these bacterial strains could promote the efficient cultivation and production of high-quality plant materials.


2009 ◽  
Vol 12 (9A) ◽  
pp. 1656-1662 ◽  
Author(s):  
Sara Tulipani ◽  
Bruno Mezzetti ◽  
Maurizio Battino

AbstractObjectiveTo review and update the current knowledge on the potential impact of strawberry on human health, with particular attention on compounds and indirect mechanisms of action not exhaustively considered.DesignPersonal perspectives and recent data.SettingInternational.ResultsOur research group was among the few groups that have recently investigated the folate content in fresh, stored and processed strawberries, and the data look very promising. As well, some in vivo evidence of the impact of strawberry intake on the folate status in humans have already been reported, but a new increasing interest on this field is strongly hoped. Furthermore, the hypouricaemic effects previously ascribed to cherry consumption need to be evaluated in respect to strawberry intake. At the moment, inconsistent results come from the few investigations designed at this proposal. In our studies, a great interindividual variability was observed on plasma urate levels in response to strawberry intake, suggesting a putative effect.ConclusionsThe mechanisms responsible for the potential health-promoting effects of strawberry may not be necessarily searched in the activity of phytochemicals. Particularly, a greater interest should be addressed to show whether a prolonged strawberry consumption may effectively improve the folate status and reduce the incidence of folate-related pathological conditions. Furthermore, the hypouricaemic effects of cherries need to be evaluated also in respect to strawberry intake, and the mechanisms of actions and anti-gout potentialities need to be studied in detail.Future investigations involving human trials should be aimed at following these underestimated scientific tracks.


2016 ◽  
Author(s):  
Nicole M. Vega ◽  
Jeff Gore

Author SummaryHost-associated bacterial communities vary extensively between individuals, but it can be very difficult to determine the sources of this variation. In this manuscript, we demonstrate experimentally how randomness in colonization can result in large differences in the composition of host-associated bacterial communities, using the nematode worm C. elegans as a tractable host model. Here, the amount of variation between individual communities is a function of two rates relevant to how bacteria colonize the host intestine, the colonization rate and the birth rate. We can therefore control the degree of variation between communities by controlling the colonization rate, using the amount of bacteria presented to the worms to control the rate at which migrants enter the intestine. When worms are fed with two neutrally-competing fluorescently labeled bacterial strains at low colonization rates, we are able to produce noise-induced bistability in this system, where each community is dominated by bacteria of only one color. These results demonstrate the potential importance of noise as a driver of variation between communities and highlight the utility of the simple model organism C. elegans for studying questions relevant to host-associated microbial communities.AbstractHost-associated bacterial communities vary extensively between individuals, but it can be very difficult to determine the sources of this heterogeneity. Here we demonstrate that stochastic bacterial community assembly in the C. elegans intestine is sufficient to produce strong inter-worm heterogeneity in community composition. When worms are fed with two neutrally-competing fluorescently labeled bacterial strains, we observe stochastically-driven bimodality in community composition, where approximately half of the worms are dominated by each bacterial strain. A simple model incorporating stochastic colonization suggests that heterogeneity between worms is driven by the low rate at which bacteria successfully establish new intestinal colonies. We can increase this rate experimentally by feeding worms at high bacterial density; in these conditions the bimodality disappears. These results demonstrate that demographic noise is a potentially important driver of diversity in bacterial community formation and suggest a role for C. elegans as a model system for ecology of host-associated communities.


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