scholarly journals Explaining the microbial diversity conundrum: can microbiome composition be crucial for host fitness, while highly divergent among healthy individuals?

2022 ◽  
Author(s):  
Itay Daybog ◽  
Oren Kolodny
Keyword(s):  
Empirical Studies ◽  
Host Population ◽  
Healthy Individuals ◽  
Apparent Paradox ◽  
Computational Framework ◽  
Rescue Effect ◽  
Host Fitness ◽  
Microbiome Composition ◽  
Β Diversity ◽  
Selection Dynamics

Recent empirical studies offer conflicting findings regarding the relation between host fitness and the composition of its microbiome, a conflict which we term the microbial β-diversity conundrum: it has been shown that the microbiome is crucial for host wellbeing and survival. At the same time, different healthy individuals' microbiome compositions, even in the same population, often differ dramatically, contrary to the notion that a vital trait should be highly conserved. Moreover, gnotobiotic individuals exhibit highly deleterious phenotypes, supporting the notion that the microbiome is paramount to host fitness. However, the introduction of almost arbitrarily selected microbiota into the system often achieves a significant rescue effect of the deleterious phenotypes, even microbiota from soil or phylogenetically distant host species, highlighting an apparent paradox. Here we suggest several solutions to the paradox using a computational framework, simulating the population dynamics of hosts and their microbiomes over multiple generations. The answers, relating to factors such as host population size, the specific mode of contribution of the microbes to host fitness, and the typical microbiome richness, offer solutions to the conundrum by creating scenarios where even when a host's fitness is determined in full by its microbiome composition, this composition has little or no effect on the natural selection dynamics of the population.

scholarly journals Gut microbiome signatures of risk and prodromal markers of Parkinson’s disease

2019 ◽  
Author(s):  
Sebastian Heinzel ◽  
Velma T. E. Aho ◽  
Ulrike Suenkel ◽  
Anna-Katharina von Thaler ◽  
Claudia Schulte ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Gut Microbiome ◽  
Physical Inactivity ◽  
Disease Onset ◽  
Rem Sleep Behavior Disorder ◽  
Sleep Behavior ◽  
Microbiome Composition ◽  
Β Diversity ◽  
The Impact

AbstractObjectivesAlterations of the gut microbiome in Parkinson’s disease (PD) have been repeatedly demonstrated. However, little is known about whether such alterations precede disease onset and how they may be related to risk and prodromal markers of PD. We investigated associations of these features with gut microbiome composition.MethodsEstablished risk and prodromal markers of PD as well as factors related to diet/lifestyle, bowel function and medication were studied in relation to bacterial α-/β-diversity, enterotypes, and taxonomic composition in stool samples of 666 elderly TREND study participants.ResultsAmong risk and prodromal markers, physical inactivity, constipation and age showed associations with α- and β-diversity, and for both measures subthreshold parkinsonism and physical inactivity showed interaction effects. Moreover, male sex, possible REM-sleep behavior disorder (RBD), smoking as well as body-mass-index, antidiabetic and urate-lowering medication were associated with β-diversity. Physical inactivity and constipation severity were increased in individuals with the Firmicutes-enriched enterotype. Subthreshold parkinsonism was least frequently observed in individuals with the Prevotella-enriched enterotype. Differentially abundant taxa were linked to constipation, physical inactivity, possible RBD, and subthreshold parkinsonism. Substantia nigra hyperechogenicity, olfactory loss, depression, orthostatic hypotension, urinary/erectile dysfunction, PD family history and the overall prodromal PD probability showed no significant microbiome associations.InterpretationSeveral risk and prodromal markers of PD are associated with changes in gut microbiome composition. However, the impact of the gut microbiome on PD risk and potential microbiome-dependent subtypes in the prodrome of PD need further investigation based on prospective clinical and (multi)omics data in incident PD cases.

scholarly journals Sputum Microbiome Composition in Patients With Squamous Cell Lung Carcinoma

2021 ◽  
Author(s):  
E. D. Baranova ◽  
V. G. Druzhinin ◽  
L. V. Matskova ◽  
P. S. Demenkov ◽  
V. P . Volobaev ◽  
...  
Keyword(s):  
Squamous Cell ◽  
Inflammatory Responses ◽  
Alpha Diversity ◽  
Taxonomic Composition ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Cell Lung Carcinoma ◽  
Microbiome Composition ◽  
Β Diversity ◽  
Genome Damage

Abstract Recent findings indicate that the microbiome can have a significant impact on the development of lung cancer by inducing inflammatory responses, causing dysbiosis and generating genome damage. The aim of this study was to search for bacterial markers of squamous cell carcinoma (LUSC). In the study, the taxonomic composition of the sputum microbiome of 40 men with untreated LUSC was compared with 40 healthy controls. Next Generation sequencing of bacterial 16S rRNA genes was used to determine the taxonomic composition of the respiratory microbiome. There was no differences in alpha diversity between the LUSC and control groups. Meanwhile, differences in the structure of bacterial communities (β diversity) among patients and controls differed significantly in sputum samples (pseudo-F = 1.65; p = 0.026). Only Streptococcus, Bacillus, Gemella and Haemophilus were found to be significantly increased in patients with LUSC compared to the control subjects, while 19 bacterial genera were significantly reduced, indicating a decrease in beta diversity in the microbiome of patients with LUSC. From our study, Streptococcus (Streptococcus agalactiae) emerges as the most likely LUSC biomarker, but more research is needed to confirm this assumption.

scholarly journals Multiple generations of antibiotic exposure and isolation influence host fitness and the microbiome in a model zooplankton species

2021 ◽  
Author(s):  
Reilly O. Cooper ◽  
Sarah Tjards ◽  
Jessica Rischling ◽  
David T. Nguyen ◽  
Clayton E. Cressler
Keyword(s):  
Daphnia Magna ◽  
Disease Risk ◽  
Control Treatment ◽  
Antibiotic Exposure ◽  
Community Members ◽  
Host Fitness ◽  
Microbiome Composition ◽  
Single Host ◽  
Multigenerational Effects ◽  
And Function

AbstractBackgroundChronic antibiotic exposure impacts host health through changes to the microbiome, increasing disease risk and reducing the functional repertoire of community members. The detrimental effects of antibiotic perturbation on microbiome structure and function after one host generation of exposure have been well-studied. However, much less is understood about the multigenerational effects of antibiotic exposure and how the microbiome may recover across host generations.ResultsIn this study, we examined microbiome composition and host fitness across five generations of exposure to a suite of three antibiotics in the model zooplankton host Daphnia magna. By utilizing a split-brood design where half of the offspring from antibiotic-exposed parents were allowed to recover and half were maintained in antibiotics, we aimed to examine recovery and resilience of the microbiome. Unexpectedly, we discovered that experimental isolation of single host individuals across generations also exerted a strong effect on microbiome composition, with composition becoming less diverse over generations regardless of treatment. Simultaneously, Daphnia magna body size and cumulative reproduction increased across generations while survival decreased. Though antibiotics did cause substantial changes to microbiome composition, the microbiome generally became similar to the no antibiotic control treatment within one generation of recovery no matter how many prior generations were spent in antibiotics.ConclusionsContrary to results found in vertebrate systems, Daphnia magna microbiome composition recovers quickly after antibiotic exposure. However, our results suggest that the isolation of individual hosts leads to the stochastic extinction of rare taxa in the microbiome, indicating that these taxa are likely maintained via transmission in host populations rather than intrinsic mechanisms. This may explain the intriguing result that microbiome diversity loss increased host fitness.

Where the rubber meets the road: The importance of implementation

2003 ◽  
Vol 26 (1) ◽  
pp. 83-84
Author(s):  
Deanna M. Barch ◽  
Todd S. Braver
Keyword(s):  
Nmda Receptor ◽  
Healthy Individuals ◽  
Computational Framework ◽  
The Road ◽  
Quantitative Estimates ◽  
Cognitive Disturbances

AbstractPhillips & Silverstein argue that a range of cognitive disturbances in schizophrenia result from a deficit in cognitive coordination attributable to NMDA receptor dysfunction. We suggest that the viability of this hypothesis would be further supported by explicit implementation in a computational framework that can produce quantitative estimates of the behavior of both healthy individuals and individuals with schizophrenia.

scholarly journals Mirror- and Eye-Gazing: An Integrative Review of Induced Altered and Anomalous Experiences

2020 ◽  
pp. 027623662096963
Author(s):  
Giovanni B. Caputo ◽  
Steven Jay Lynn ◽  
James Houran
Keyword(s):  
Body Dysmorphic Disorder ◽  
Empirical Studies ◽  
The Body ◽  
Clinical Samples ◽  
Altered States ◽  
Healthy Individuals ◽  
External Reality ◽  
Self Identity ◽  
Perceptual Distortions ◽  
Mirror Gazing

We critically reviewed the protocols, results, and potential implications from empirical studies ( n = 44) on mirror-gazing (including the “psychomanteum”) and eye-to-eye gazing, both in healthy individuals and clinical patients, including studies of hypnotic mirrored self-misidentification, mirror-gazing in body dysmorphic disorder and schizophrenia. We found these methods to be effective for eliciting altered states or anomalous experiences under controlled conditions and in non-clinical samples. Mirror-gazing and eye-to-eye-gazing produced anomalous experiences almost exclusively in the visual, bodily, and self-identity modalities, whereas psychomanteum experiences tended also to involve voices, smells, and bodily touches. The complexity, diversity, and specificity in contents across these anomalous experiences suggest mechanisms beyond perceptual distortions or illusions. We argue that mirror- and eye-gazing anomalous perceptions implicate different mechanisms that induce (i) Derealization (anomalous perceptions of external reality); (ii) Depersonalization (anomalous perceptions of the body), and (iii) Dissociated identity (anomalous perceptions of another identity in place of the self in mirror-gazing or in place of the other in eye-to-eye gazing). These interpretations suggest directions for future researches.

scholarly journals Epidemic and endemic pathogen dynamics correspond to distinct host population microbiomes at a landscape scale

2017 ◽  
Vol 284 (1857) ◽  
pp. 20170944 ◽  
Author(s):  
Andrea J. Jani ◽  
Roland A. Knapp ◽  
Cheryl J. Briggs
Keyword(s):  
Infectious Disease ◽  
Fungal Pathogen ◽  
Batrachochytrium Dendrobatidis ◽  
Infection Intensity ◽  
Host Population ◽  
Symbiotic Bacteria ◽  
Skin Microbiome ◽  
Pathogen Infection ◽  
Microbiome Composition ◽  
Pathogen Invasion

Infectious diseases have serious impacts on human and wildlife populations, but the effects of a disease can vary, even among individuals or populations of the same host species. Identifying the reasons for this variation is key to understanding disease dynamics and mitigating infectious disease impacts, but disentangling cause and correlation during natural outbreaks is extremely challenging. This study aims to understand associations between symbiotic bacterial communities and an infectious disease, and examines multiple host populations before or after pathogen invasion to infer likely causal links. The results show that symbiotic bacteria are linked to fundamentally different outcomes of pathogen infection: host–pathogen coexistence (endemic infection) or host population extirpation (epidemic infection). Diversity and composition of skin-associated bacteria differed between populations of the frog, Rana sierrae , that coexist with or were extirpated by the fungal pathogen, Batrachochytrium dendrobatidis (Bd). Data from multiple populations sampled before or after pathogen invasion were used to infer cause and effect in the relationship between the fungal pathogen and symbiotic bacteria. Among host populations, variation in the composition of the skin microbiome was most strongly predicted by pathogen infection severity, even in analyses where the outcome of infection did not vary. This result suggests that pathogen infection shapes variation in the skin microbiome across host populations that coexist with or are driven to extirpation by the pathogen. By contrast, microbiome richness was largely unaffected by pathogen infection intensity, but was strongly predicted by geographical region of the host population, indicating the importance of environmental or host genetic factors in shaping microbiome richness. Thus, while both richness and composition of the microbiome differed between endemic and epidemic host populations, the underlying causes are most likely different: pathogen infection appears to shape microbiome composition, while microbiome richness was less sensitive to pathogen-induced disturbance. Because higher richness was correlated with host persistence in the presence of Bd, and richness appeared relatively stable to Bd infection, microbiome richness may contribute to disease resistance, although the latter remains to be directly tested.

Selfish DNA as a method of pest control

1994 ◽  
Vol 344 (1309) ◽  
pp. 313-324 ◽  
Keyword(s):  
Genetic Load ◽  
Single Copy ◽  
Mendelian Inheritance ◽  
Host Population ◽  
Molecular Techniques ◽  
Uniparental Inheritance ◽  
Pest Species ◽  
Agricultural Pests ◽  
Selfish Dna ◽  
Host Fitness

The inheritance of most genes is tightly controlled, governed by the rules of mendelian inheritance if nuclear or uniparental inheritance if cytoplasmic. A few notable genes and cytoplasmic genomes have escaped this regulation. Such genes may spread by increasing their own rate of transmission despite reducing host fitness and may be regarded as ‘selfish’. Their population genetics are described and it appears they may impose a significant genetic load on the host population. Modern molecular techniques may enable similar loads to be imposed on pest species either by transferring selfish genes between species, or by linking deleterious genes to a selfish locus. Alternatively, ‘modifier’ genes that eliminate the virulent, or disease vectorial capacity, of the pest population may be introduced by linkage to a selfish locus. Selfish elements present in multiple copies may be preferable to single-copy elements as the former are capable of a larger reduction in host fitness. The practical application of these agents depends on five factors: (i) the rate of ‘reversion’ to a non-selfish form; (ii) the evolution of host repressor systems; (iii) their effect on host fitness, which determines their rate of invasion; (iv) the mechanism regulating host population size in the field; and (v) their ease of manipulation in the laboratory. The first two factors are the most uncertain in most systems, but should be amenable to experimental analysis. It is proposed that the development of such techniques may result in powerful new methods of population control which may be applied to both agricultural pests and disease vectors.

scholarly journals Dysbiosis of gut microbiota and its correlation with dysregulation of cytokines in psoriasis patients

2021 ◽  
Author(s):  
Xinyue Zhang ◽  
Kun Guo ◽  
Linjing Shi ◽  
Ting Sun ◽  
Songmei Geng
Keyword(s):  
Gut Microbiota ◽  
Relative Abundance ◽  
Gut Microbiome ◽  
High Throughput Sequencing ◽  
Interleukin 2 ◽  
Negative Relationship ◽  
Healthy Individuals ◽  
Microbial Composition ◽  
Microbiome Composition ◽  
The Relationship

Abstract Background: Psoriasis is an inflammatory skin disease associated with multiple comorbidities and substantially diminishes patients’ quality of life. The gut microbiome has become a hot topic in psoriasis as it has been shown to affect both allergy and autoimmunity diseases in recent studies. Our objective was to identify differences in the fecal microbial composition of patients with psoriasis compared with healthy individuals to unravel the microbiota profiling in this autoimmune disease.Results: We collected fecal samples from 30 psoriasis patients and 30 healthy controls, sequenced them by 16S rRNA high-throughput sequencing, and identified the gut microbial composition using bioinformatic analyses including Quantitative Insights into Microbial Ecology (QIIME) and Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt). Our results showed that different relative abundance of certain bacterial taxa between psoriasis patients and healthy individuals, including Faecalibacterium and Megamonas, were increased in patients with psoriasis. It’s also implicated that many cytokines act as main effect molecules in the pathology of psoriasis. We selected the inflammation-related indicators that were abnormal in psoriasis patients and found the microbiome variations were associated with the level of them, especially interleukin-2 receptor showed a positive relationship with Phascolarctobacterium and a negative relationship with the dialister. The relative abundance of Phascolarctobacterium and dialister can be regard as predictors of psoriasis activity. The correlation analysis based on microbiota and Inflammation-related indicators showed that microbiota dysbiosis might induce an abnormal immune response in psoriasis. Conclusions: We concluded that the gut microbiome composition in psoriasis patients has been altered markedly and provides evidence to understand the relationship between gut microbiota and psoriasis. More mechanistic experiments are needed to determine whether the differences observed in gut microbiota are the cause or consequences of psoriasis and whether the relationship between gut microbiota and cytokines was involved.

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