scholarly journals Markers of Gut Barrier Function and Microbial Translocation Associate with Lower Gut Microbial Diversity in People with HIV

Viruses ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1891
Author(s):  
Ronald J. Ellis ◽  
Jennifer E. Iudicello ◽  
Robert K. Heaton ◽  
Stéphane Isnard ◽  
John Lin ◽  
...  

People with human immunodeficiency virus (HIV) (PWH) have reduced gut barrier integrity (“leaky gut”) that permits diffusion of microbial antigens (microbial translocation) such as lipopolysaccharide (LPS) into the circulation, stimulating inflammation. A potential source of this disturbance, in addition to gut lymphoid tissue CD4+ T-cell depletion, is the interaction between the gut barrier and gut microbes themselves. We evaluated the relationship of gut barrier integrity, as indexed by plasma occludin levels (higher levels corresponding to greater loss of occludin from the gut barrier), to gut microbial diversity. PWH and people without HIV (PWoH) participants were recruited from community sources and provided stool, and 16S rRNA amplicon sequencing was used to characterize the gut microbiome. Microbial diversity was indexed by Faith’s phylogenetic diversity (PD). Participants were 50 PWH and 52 PWoH individuals, mean ± SD age 45.6 ± 14.5 years, 28 (27.5%) women, 50 (49.0%) non-white race/ethnicity. PWH had higher gut microbial diversity (Faith’s PD 14.2 ± 4.06 versus 11.7 ± 3.27; p = 0.0007), but occludin levels were not different (1.84 ± 0.311 versus 1.85 ± 0.274; p = 0.843). Lower gut microbial diversity was associated with higher plasma occludin levels in PWH (r = −0.251; p = 0.0111), but not in PWoH. A multivariable model demonstrated an interaction (p = 0.0459) such that the correlation between Faith’s PD and plasma occludin held only for PWH (r = −0.434; p = 0.0017), but not for PWoH individuals (r = −0.0227; p = 0.873). The pattern was similar for Shannon alpha diversity. Antiretroviral treatment and viral suppression status were not associated with gut microbial diversity (ps > 0.10). Plasma occludin levels were not significantly related to age, sex or ethnicity, nor to current or nadir CD4 or plasma viral load. Higher occludin levels were associated with higher plasma sCD14 and LPS, both markers of microbial translocation. Together, the findings suggest that damage to the gut epithelial barrier is an important mediator of microbial translocation and inflammation in PWH, and that reduced gut microbiome diversity may have an important role.

Rheumatology ◽  
2020 ◽  
Author(s):  
Maxim B Freidin ◽  
Maria A Stalteri ◽  
Philippa M Wells ◽  
Genevieve Lachance ◽  
Andrei-Florin Baleanu ◽  
...  

Abstract Objectives Chronic widespread musculoskeletal pain (CWP) is a characteristic symptom of fibromyalgia, which has been shown to be associated with an altered gut microbiome. Microbiome studies to date have not examined the milder CWP phenotype specifically nor have they explored the role of raised BMI. The aim of this study was to investigate whether the microbiome is abnormal in CWP. Methods CWP was assessed using a standardized screening questionnaire in female volunteers from the TwinsUK cohort including 113 CWP cases and 1623 controls. The stool microbiome was characterised using 16S rRNA amplicon sequencing and amplicon sequence variants (ASVs), and associations with CWP examined using linear mixed-effects models adjusting for BMI, age, diet, family relatedness and technical factors. Results Alpha diversity was significantly lower in CWP cases than controls (Mann–Whitney test, p-values 2.3e-04 and 1.2e-02, respectively). The species Coprococcus comes was significantly depleted in CWP cases (p.adj = 3.04e-03). A genome-wide association study (GWAS) performed for C. comes in TwinsUK followed by meta-analysis with three Dutch cohorts (total n = 3521) resulted in nine suggestive regions, with the most convincing on chromosome 4 near the TRAM1L1 gene (rs76957229, p= 7.4e-8). A Mendelian randomisation study based on the results of the GWAS did not support a causal role for C. comes on the development of CWP. Conclusions We have demonstrated reduced diversity in the microbiome in CWP, indicating an involvement of the gut microbiota in CWP; prospectively the microbiome may offer therapeutic opportunities for this condition.


2019 ◽  
Vol 10 (3) ◽  
pp. 265-278 ◽  
Author(s):  
V. Stadlbauer ◽  
A. Horvath ◽  
I. Komarova ◽  
B. Schmerboeck ◽  
N. Feldbacher ◽  
...  

The gut is hypothesised to play an important role in the development and progression of sepsis. It is however unknown whether the gut microbiome and the gut barrier function is already altered early in sepsis development and whether it is possible to modulate the microbiome in early sepsis. Therefore, a randomised, double blind, placebo-controlled pilot study to examine the alterations of the microbiome and the gut barrier in early sepsis and the influence of a concomitant probiotic intervention on dysbiosis at this early stage of the disease was conducted. Patients with early sepsis, defined as fulfilling the sepsis definition from the 2012 Surviving Sepsis Campaign guidelines but without signs of organ failure, received multispecies probiotic (Winclove 607 based on Omnibiotic® 10 AAD) for 28 days. Gut microbiome composition, function, gut barrier and bacterial translocation were studied. Patients with early sepsis had a significantly lower structural and functional alpha diversity, clustered differently and showed structural alterations on all taxonomic levels. Gut permeability was unaltered but endotoxin, endotoxin binding proteins and peptidoglycans were elevated in early sepsis patients compared to controls. Probiotic intervention successfully increased probiotic strains in stool and led to an improvement of functional diversity. Microbiome composition and function are altered in early sepsis. Probiotic intervention successfully modulates the microbiome and is therefore a promising tool for early intervention in sepsis.


2019 ◽  
Vol 7 (9) ◽  
pp. 338 ◽  
Author(s):  
Prochazkova ◽  
Roubalova ◽  
Dvorak ◽  
Tlaskalova-Hogenova ◽  
Cermakova ◽  
...  

The change in the gut microbiome and microbial metabolites in a patient suffering from severe and enduring anorexia nervosa (AN) and diagnosed with small intestinal bacterial overgrowth syndrome (SIBO) was investigated. Microbial gut dysbiosis is associated with both AN and SIBO, and therefore gut microbiome changes by serial fecal microbiota transplantation (FMT) is a possible therapeutic modality. This study assessed the effects of FMT on gut barrier function, microbiota composition, and the levels of bacterial metabolic products. The patient treatment with FMT led to the improvement of gut barrier function, which was altered prior to FMT. Very low bacterial alpha diversity, a lack of beneficial bacteria, together with a great abundance of fungal species were observed in the patient stool sample before FMT. After FMT, both bacterial species richness and gut microbiome evenness increased in the patient, while the fungal alpha diversity decreased. The total short-chain fatty acids (SCFAs) levels (molecules presenting an important source of energy for epithelial gut cells) gradually increased after FMT. Contrarily, one of the most abundant intestinal neurotransmitters, serotonin, tended to decrease throughout the observation period. Overall, gut microbial dysbiosis improvement after FMT was considered. However, there were no signs of patient clinical improvement. The need for an in-depth analysis of the donor´s stool and correct selection pre-FMT is evident.


2021 ◽  
Author(s):  
Ravichandra Vemuri ◽  
Alistaire Ruggiero ◽  
Jordyn B. Whitfield ◽  
Greg O Dugan ◽  
Mark J Cline ◽  
...  

Accumulating evidence indicates a link between gut barrier dysfunction and hypertension. However, it is unclear whether hypertension dictates gut barrier dysfunction or vice versa and whether the gut microbiome plays a role. To better understand this relationship, first, we cross-sectionally examined hypertension and other cardio-metabolic risk factors and gut barrier function in a population of 150 nonhuman primates. Interestingly, the animals with hypertension showed evidence of gut barrier dysfunction (i.e., translocation of microbes through the gut wall), as indicated by higher plasma levels of lipopolysaccharide-binding protein (LBP)-1, compared to normotensive animals. Further, plasma LBP-1 levels were strongly correlated with diastolic blood pressure, independent of age and other health markers, suggesting specificity of the effect of hypertension on microbial translocation. In a subsequent longitudinal study (analysis at baseline, 12 and 27 months), hypertensive animals had higher plasma levels of LBP-1 at all the time points and greater bacterial gene expression in mesenteric lymph nodes compared to normotensive animals, confirming microbe translocation. Concomitantly, we identified distinct dysbiosis in the gut microbial signature of hypertensive versus normotensive animals at 12 and 27 months. These results suggest that hypertension drives microbial translocation in the gut and eventually unhealthy shifts in the gut microbiome, possibly contributing to poor health outcomes, providing further impetus for the management of hypertension.


2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Robert C. Kaplan ◽  
Zheng Wang ◽  
Mykhaylo Usyk ◽  
Daniela Sotres-Alvarez ◽  
Martha L. Daviglus ◽  
...  

Abstract Background Hispanics living in the USA may have unrecognized potential birthplace and lifestyle influences on the gut microbiome. We report a cross-sectional analysis of 1674 participants from four centers of the Hispanic Community Health Study/Study of Latinos (HCHS/SOL), aged 18 to 74 years old at recruitment. Results Amplicon sequencing of 16S rRNA gene V4 and fungal ITS1 fragments from self-collected stool samples indicate that the host microbiome is determined by sociodemographic and migration-related variables. Those who relocate from Latin America to the USA at an early age have reductions in Prevotella to Bacteroides ratios that persist across the life course. Shannon index of alpha diversity in fungi and bacteria is low in those who relocate to the USA in early life. In contrast, those who relocate to the USA during adulthood, over 45 years old, have high bacterial and fungal diversity and high Prevotella to Bacteroides ratios, compared to USA-born and childhood arrivals. Low bacterial diversity is associated in turn with obesity. Contrasting with prior studies, our study of the Latino population shows increasing Prevotella to Bacteroides ratio with greater obesity. Taxa within Acidaminococcus, Megasphaera, Ruminococcaceae, Coriobacteriaceae, Clostridiales, Christensenellaceae, YS2 (Cyanobacteria), and Victivallaceae are significantly associated with both obesity and earlier exposure to the USA, while Oscillospira and Anaerotruncus show paradoxical associations with both obesity and late-life introduction to the USA. Conclusions Our analysis of the gut microbiome of Latinos demonstrates unique features that might be responsible for health disparities affecting Hispanics living in the USA.


Nutrients ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 2414
Author(s):  
Laura Sanjulián ◽  
Alexandre Lamas ◽  
Rocío Barreiro ◽  
Alberto Cepeda ◽  
Cristina A. Fente ◽  
...  

The objective of this work was to characterize the microbiota of breast milk in healthy Spanish mothers and to investigate the effects of lactation time on its diversity. A total of ninety-nine human milk samples were collected from healthy Spanish women and were assessed by means of next-generation sequencing of 16S rRNA amplicons and by qPCR. Firmicutes was the most abundant phylum, followed by Bacteroidetes, Actinobacteria, and Proteobacteria. Accordingly, Streptococcus was the most abundant genus. Lactation time showed a strong influence in milk microbiota, positively correlating with Actinobacteria and Bacteroidetes, while Firmicutes was relatively constant over lactation. 16S rRNA amplicon sequencing showed that the highest alpha-diversity was found in samples of prolonged lactation, along with wider differences between individuals. As for milk nutrients, calcium, magnesium, and selenium levels were potentially associated with Streptococcus and Staphylococcus abundance. Additionally, Proteobacteria was positively correlated with docosahexaenoic acid (DHA) levels in breast milk, and Staphylococcus with conjugated linoleic acid. Conversely, Streptococcus and trans-palmitoleic acid showed a negative association. Other factors such as maternal body mass index or diet also showed an influence on the structure of these microbial communities. Overall, human milk in Spanish mothers appeared to be a complex niche shaped by host factors and by its own nutrients, increasing in diversity over time.


Author(s):  
Amedeo Minichino ◽  
Matthew A. Jackson ◽  
Marta Francesconi ◽  
Claire J. Steves ◽  
Cristina Menni ◽  
...  

AbstractAnhedonia and amotivation are debilitating symptoms and represent unmet therapeutic needs in a range of clinical conditions. The gut-microbiome-endocannabinoid axis might represent a potential modifiable target for interventions. Based on results obtained from animal models, we tested the hypothesis that the endocannabinoid system mediates the association between gut-microbiome diversity and anhedonia/amotivation in a general population cohort. We used longitudinal data collected from 786 volunteer twins recruited as part the TwinsUK register. Our hypothesis was tested with a multilevel mediation model using family structure as random intercept. The model was set using alpha diversity (within-individual gut-microbial diversity) as predictor, serum and faecal levels of the endocannabinoid palmitoylethanolamide (PEA) as mediator, and anhedonia/amotivation as outcome. PEA is considered the endogenous equivalent of cannabidiol, with increased serum levels believed to have anti-depressive effects, while increased stool PEA levels, reflecting increased excretion, are believed to have opposite, detrimental, effects on mental health. We therefore expected that either reduced serum PEA or increased stool PEA would mediate the association between microbial diversity and anhedonia amotivation. Analyses were adjusted for obesity, diet, antidepressant use, sociodemographic and technical covariates. Data were imputed using multiple imputation by chained equations. Mean age was 65.2 ± 7.6; 93% of the sample were females. We found a direct, significant, association between alpha diversity and anhedonia/amotivation (β = −0.37; 95%CI: −0.71 to −0.03; P = 0.03). Faecal, but not serum, levels of the endocannabinoid palmitoylethanolamide (PEA) mediated this association: the indirect effect was significant (β = −0.13; 95%CI: −0.24 to −0.01; P = 0.03), as was the total effect (β = −0.38; 95%CI: −0.72 to −0.04; P = 0.03), whereas the direct effect of alpha diversity on anhedonia/amotivation was attenuated fully (β = −0.25; 95%CI: −0.60 to 0.09; P = 0.16). Our results suggest that gut-microbial diversity might contribute to anhedonia/amotivation via the endocannabinoid system. These findings shed light on the biological underpinnings of anhedonia/amotivation and suggest the gut microbiota-endocannabinoid axis as a promising therapeutic target in an area of unmet clinical need.


2017 ◽  
Author(s):  
Jon G Sanders ◽  
Piotr Lukasik ◽  
Megan E Frederickson ◽  
Jacob A Russell ◽  
Ryuichi Koga ◽  
...  

AbstractAbundance is a key parameter in microbial ecology, and important to estimates of potential metabolite flux, impacts of dispersal, and sensitivity of samples to technical biases such as laboratory contamination. However, modern amplicon-based sequencing techniques by themselves typically provide no information about the absolute abundance of microbes. Here, we use fluorescence microscopy and quantitative PCR as independent estimates of microbial abundance to test the hypothesis that microbial symbionts have enabled ants to dominate tropical rainforest canopies by facilitating herbivorous diets, and compare these methods to microbial diversity profiles from 16S rRNA amplicon sequencing. Through a systematic survey of ants from a lowland tropical forest, we show that the density of gut microbiota varies across several orders of magnitude among ant lineages, with median individuals from many genera only marginally above detection limits. Supporting the hypothesis that microbial symbiosis is important to dominance in the canopy, we find that the abundance of gut bacteria is positively correlated with stable isotope proxies of herbivory among canopy-dwelling ants, but not among ground-dwelling ants. Notably, these broad findings are much more evident in the quantitative data than in the 16S rRNA sequencing data. Our results help to resolve a longstanding question in tropical rainforest ecology, and have broad implications for the interpretation of sequence-based surveys of microbial diversity.


2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Fang Liu ◽  
Seul A. Lee ◽  
Stephen M. Riordan ◽  
Li Zhang ◽  
Lixin Zhu

Anti-cytokine antibodies are used in treating chronic inflammatory diseases and autoimmune diseases such as inflammatory bowel disease and rheumatic diseases. Patients with these diseases often have a compromised gut barrier function, suggesting that anti-cytokine antibodies may contribute to the re-establishment of gut barrier integrity, in addition to their immunomodulatory effects. This paper reviews the effects of anti-cytokine antibodies on gut barrier function and their mechanisms.


2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 425-425
Author(s):  
Sunhye Lee ◽  
Michael Goodson ◽  
Wendie Vang ◽  
Karen Kalanetra ◽  
Daniela Barile ◽  
...  

Abstract Objectives 2’-fucosyllactose (2’-FL), the most predominant oligosaccharide found in human milk, acts as a prebiotic with beneficial effects on the host. The aim of this study was to determine the beneficial effect of 2’-FL on intestinal barrier integrity and metabolic functions in low-fat (LF)- and high-fat (HF)-fed mice. Methods Male C57/BL6 mice (n = 32, 8/group; 6 weeks old, JAX, CA) were counter-balanced into four weight-matched groups and fed either a low-fat (LF; 10% kcal fat with 7% kcal sucrose) or HF (45% kcal fat with 17% kcal sucrose) with or without supplementation of 2’-FL in the diet [10% (w/w), 8 weeks; LF/2’-FL or HF/2’-FL; BASF, Germany]. General phenotypes (body weight, energy intake, fat and lean mass), intestinal permeability (ex vivo in Ussing chambers), lipid profiles, and microbial metabolites were assessed. Results 2’-FL significantly attenuated the HF-induced increase in body fat mass with a trend to decrease body weight gain. 2’-FL significantly decreased intestinal permeability in LF-fed mice with a trend for a decrease in HF-fed mice. This was associated with a significant increase in interleukin-22, a cytokine known to have a protective role in intestinal barrier function. Visceral adipocyte size was significantly decreased by 2’-FL in both LF- and HF-fed mice. 2’-FL suppressed HF-induced upregulation of adipogenic transcription factors peroxisome proliferator-activated receptor gamma and sterol regulatory element binding protein-1c in the liver. Lastly, 2’-FL supplementation led to a significant elevation of lactic acid concentration in the cecum of HF-fed mice, which is known to be a product from beneficial microbes. Conclusions 2’-FL supplementation improved gut barrier integrity and lipid metabolism in mice with and without the metabolic challenge of HF feeding. These findings support the use of 2’-FL in the control of gut barrier function and metabolic homeostasis under normal and abnormal physiological conditions. Funding Sources BASF (Germany).


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