scholarly journals Depletion of microbiome-derived molecules in the host using Clostridium genetics

Science ◽  
2019 ◽  
Vol 366 (6471) ◽  
pp. eaav1282 ◽  
Author(s):  
Chun-Jun Guo ◽  
Breanna M. Allen ◽  
Kamir J. Hiam ◽  
Dylan Dodd ◽  
Will Van Treuren ◽  
...  

The gut microbiota produce hundreds of molecules that are present at high concentrations in the host circulation. Unraveling the contribution of each molecule to host biology remains difficult. We developed a system for constructing clean deletions in Clostridium spp., the source of many molecules from the gut microbiome. By applying this method to the model commensal organism Clostridium sporogenes, we knocked out genes for 10 C. sporogenes–derived molecules that accumulate in host tissues. In mice colonized by a C. sporogenes for which the production of branched short-chain fatty acids was knocked out, we discovered that these microbial products have immunoglobulin A–modulatory activity.

Circulation ◽  
2020 ◽  
Vol 141 (Suppl_1) ◽  
Author(s):  
Moira K Differding ◽  
Lawrence J Appel ◽  
Nisa Maruthur ◽  
Stephen Juraschek ◽  
Edgar R Miller ◽  
...  

Background: Murine models indicate that gut microbiota, and the short chain fatty acids (SCFAs) they produce from fermentation of fiber, play a role in blood pressure (BP) regulation. However, few human studies have examined how gut microbiota and serum SCFAs are associated with hypertension. Objective: We examined associations of gut microbiota composition and serum SCFAs with hypertension and BP, hypothesizing an inverse association with serum SCFAs. Methods: We performed a cross-sectional analysis of baseline data from a trial of overweight and obese adult cancer survivors. We measured 1 ) the gut microbiome by extracting microbial DNA from stool and sequencing the 16S rRNA V4 region and 2 ) serum SCFA using liquid chromatography mass spectrometry. Hypertension was defined as systolic BP ≥ 130, diastolic BP ≥ 80 mmHg, self-report, or use of hypertension medications. We used beta-binomial models to test differential abundance of microbial amplicon sequence variants by hypertension , and linear regression to examine log-transformed SCFAs with BP. We adjusted models for age, sex, race, fiber, BMI and medications (in BP models). Results: Of 111 participants with complete data, 73 had hypertension. Hypertensive participants differed by age (mean 62 vs. 56y) and sex (73% vs. 90% female), but not race (46% black) or BMI (mean 35 kg/m 2 ). Alpha and beta diversity were not associated with hypertension (Ps>0.05). Hypertensive participants had higher abundance of Bacteroides, Parabacteroides, Bifidobacterium and Escherichia , and lower Lachnospiraceae, Haemophilus and Faecalibacterium ( Figure) . Serum acetate was negatively associated with systolic BP (β=-3.3 mmHg difference per 1 SD increment acetate, 95% CI: -6.1, -0.6); other SCFAs were not associated (Ps>0.05). Conclusion: A Bacteroides dominated microbiota was positively associated with hypertension. Acetate, the most abundant circulating SCFA, was negatively associated with BP. Determining whether the associations are causal or not warrants further investigation.


2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Marianne Collard ◽  
Nataleigh Austin ◽  
Ann Tallant ◽  
Patricia Gallagher

Abstract Objectives The goal of this study was to determine if a proprietary muscadine grape seed and skin extract (MGE) inhibits triple negative breast cancer (TNBC) metastasis and alters the gut microbiota. Methods 4T1 TNBC cells were injected into the mammary fat pad of 6-week-old female Balb/c mice. After 2 weeks, tumors were surgically removed and mice were placed into a control group (n = 8) or a treatment group that received 0.1 mg/mL total phenolics MGE (Piedmont R&D) in the drinking water (n = 8). Mice were sacrificed after 4 weeks; tissues and fecal samples were collected for analysis. Immunohistochemistry (Ki67, α-SMA) and hemotoxylin and eosin staining were used to quantify metastases using the inForm© 2.2 software. Gut microbial composition was determined by 16S rRNA sequencing and short chain fatty acids were detected by gas chromatography (Microbiome Insights). Data are expressed as means ± SEM using student's t-test. Results MGE reduced Ki67 cell positivity in the lungs and livers of mice, indicating reduced metastatic proliferation (9.3 ± 0.9% vs 6.2 ± 0.7% and 5.0 ± 1.5% vs 0.77 ± 0.2% cells, respectively; P < 0.01), and decreased cancer associated fibroblasts in the lungs (5.3 ± 1.0% vs 3.0 ± 0.5% cells; P < 0.05), which are associated with metastasis. MGE significantly reduced the number (4.7 ± 0.7 vs 2.2 ± 0.4 tumors/field; P < 0.01) and size (1358 ± 48 vs 1121 ± 47 pixels; P < 0.01) of liver metastases, resulting in decreased metastatic tumor burden (6656 ± 1220 vs 3096 ± 644 total area in pixels; P < 0.01). Attenuated TNBC metastasis correlated with MGE-induced changes in gut microbiota. Alpha diversity (4.15 ± 0.10 vs 4.51 ± 0.13 Shannon index; P < 0.05) and the Firmicutes to Bacteroidetes ratio (0.37 ± 0.07 vs 0.76 ± 0.12; P < 0.05) were significantly increased in MGE-treated mice, indicating enhanced microbial richness and increased energy harvest by the gut microbiome. Butyrate-producing bacteria, such as Ruminococcus, Butyricicoccus and Lachnospiraceae, were increased with MGE (P < 0.05) as well as the anti-inflammatory compound butyrate relative to other short-chain fatty acids (25.0 ± 2.7% vs 75.3 ± 15.5%; P < 0.01). Conclusions These data show that MGE attenuates TNBC metastasis in association with alterations in the gut microbiome, suggesting that MGE may be an effective treatment against TNBC metastatic progression. Funding Sources Chronic Disease Research Fund.


2018 ◽  
Author(s):  
Chun-Jun Guo ◽  
Breanna M. Allen ◽  
Kamir J. Hiam ◽  
Dylan Dodd ◽  
Will van Treuren ◽  
...  

ABSTRACTThe gut microbiota produce hundreds of molecules that are present at high concentrations in circulation and whose levels vary widely among humans. In most cases, molecule production has not been linked to specific bacterial strains or metabolic pathways, and unraveling the contribution of each molecule to host biology remains difficult. A general system to ‘toggle’ molecules in this pool on/off in the host would enable interrogation of the mechanisms by which they modulate host biology and disease processes. Such a system has been elusive due to limitations in the genetic manipulability of Clostridium and its relatives, the source of many molecules in this pool. Here, we describe a method for reliably constructing clean deletions in a model commensal Clostridium, C. sporogenes (Cs), including multiply mutated strains. We demonstrate the utility of this method by using it to ‘toggle’ off the production of ten Cs-derived molecules that accumulate in host tissues. By comparing mice colonized by wild-type Cs versus a mutant deficient in the production of branched short-chain fatty acids, we discover a previously unknown IgA-modulatory activity of these abundant microbiome-derived molecules. Our method opens the door to interrogating and sculpting a highly concentrated pool of chemicals from the microbiome.


2020 ◽  
Author(s):  
Anouck Becker ◽  
Mosab Abuazab ◽  
Andreas Schwiertz ◽  
Silke Walter ◽  
Klaus Faßbender ◽  
...  

Abstract Background. Multiple Sclerosis (MS) is primarily considered as a neuro-inflammatory CNS disease. Yet, experimental data suggest a role for gut microbiota and microbial products like short chain fatty acids (SCFA) in the pathogenesis of MS. Very recently a high-ranked publication reported beneficial effects of propionate, a SCFA, in MS patients. Based on experimental and preliminary human data, we hypothesized that not only the gut microbiota but also microbial products and fecal inflammatory markers might be altered in MS.Methods. In a pilot study, we investigated fecal markers (short chain fatty acids, calprotectin) as well as clinical markers in patients with relapsing-remitting MS (RRMS) under different therapeutic regimes and compared the results to age-matched control subjects.Results. We observed a non-significant reduction in fecal SCFA in RRMS patients compared to control subjects. Fecal calprotectin concentrations did not differ significantly between MS patients and control subjects. We observed a significant reduction in fecal SCFA concentrations in women compared to men.Conclusions. We conclude that the observed sex-associated difference in fecal SCFA concentrations might be a contributing factor in the pathogenesis of MS, especially when taking into account the female predominance in MS. We suggest investigating the role of SCFA in MS in a longitudinal study (starting in drug-naïve patients) in larger cohorts of MS patients with defined therapeutic regimes. Such a study would allow to distinguish between drug effects and disease-immanent effects and might help to identify a potentially modifiable sex-associated contributing factor in MS.Trial registration. Registered by the local Ethics Committee (Reg.Nr. 81/18, Ethikkommission der Aerztekammer des Saarlandes, Saarbruecken, Germany).


Author(s):  
Qing Liu ◽  
Xiaoli Tian ◽  
Daisuke Maruyama ◽  
Mehrdad Arjomandi ◽  
Arun Prakash

Microbial metabolites produced by the gut microbiome, e.g. short-chain fatty acids (SCFA), have been found to influence lung physiology and injury responses. However, how lung immune activity is regulated by SCFA is unknown. We examined fresh human lung tissue and observed the presence of SCFA with inter-individual variability. In vitro, SCFA were capable of modifying the metabolic programming in LPS-exposed alveolar macrophages (AM). We hypothesized that lung immune tone could be defined by baseline detection of lung intracellular IL-1β. Therefore, we interrogated naïve mouse lungs with intact gut microbiota for IL-1β mRNA expression and localized its presence within alveolar spaces, specifically within AM subsets. We established that metabolically active gut microbiota, that produce SCFA, can transmit LPS and SCFA to the lung and thereby could create primed lung immunometabolic tone. To understand how murine lung cells sensed and upregulated IL-1β in response to gut microbiome-derived factors, we determined that, in vitro, AM and AT2 cells expressed SCFA receptors, FFAR2, FFAR3, and IL-1β but with distinct expression patterns and different responses to LPS. Finally, we observed that IL-1β, FFAR2 and FFAR3 were expressed in isolated human AM and AT2 cells ex-vivo, but in fresh human lung sections in situ, only AM expressed IL-1β at rest and after LPS challenge. Together, this translational study using mouse and human lung tissue and cells point to an important role for the gut microbiome and their SCFA in establishing and regulating lung immune tone.


2020 ◽  
Vol 15 (1) ◽  
pp. 52-56
Author(s):  
Sri Winarti ◽  
Agung Pasetyo

The consumption of prebiotics is known to affect the balance of gut microbiota. The purpose of this study was to explore how a galactomannan-rich effervescent drink can affect the population of Lactobacillus, Bifidobacterium, E. coli, and the concentration of short-chain fatty acids in the cecum of rats. Twenty-eight male Wistar rats (aged 2 months) were divided equally into 7 groups and treated orally each day for 15 days with 2 mL effervescent drinks with increasing levels of prebiotic galactomannan. The dosage of 500 mg galactomannan increased the growth of Lactobacillus spp. and Bifidobacterium spp. with inhibition of the growth of E.coli with increased formation of short-chain fatty acids such as acetate, propionate, and butyrate in the cecum of rats.


2020 ◽  
Vol 70 ◽  
pp. 20-22 ◽  
Author(s):  
Daniel Grün ◽  
Valerie C. Zimmer ◽  
Jil Kauffmann ◽  
Jörg Spiegel ◽  
Ulrich Dillmann ◽  
...  

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
B Verhaar ◽  
D Collard ◽  
A Prodan ◽  
J.H.M Levels ◽  
A.H Zwinderman ◽  
...  

Abstract Background Gut microbiome composition is shaped by a combination of host genetic make-up and dietary habits. In addition, large ethnic differences exist in microbiome composition. Several studies in humans and animals have shown that differences in gut microbiota and its metabolites, including short chain fatty acids (SCFA), are associated with blood pressure (BP). We hypothesized that gut microbiome composition and its metabolites may be differently associated with BP across ethnic groups. Purpose To investigate associations of gut microbiome composition and fecal SCFA levels with BP across different ethnic groups. Methods We assessed the association between gut microbiome composition and office BP among 4672 subjects (mean age 49.8±11.7 years, 52%F) of 6 different ethnic groups participating in the HELIUS study. Gut microbiome composition was determined using 16S rRNA sequencing. Associations between microbiome composition and blood pressure were assessed using machine learning prediction models. The resulting best predictors were correlated with BP using Spearman's rank correlations. Fecal SCFA levels were measured with high-performance liquid chromatography in an age- and body mass index (BMI)-matched subgroup of 200 participants with either extreme low or high systolic BP. Differences in abundances of best predictors and fecal SCFA levels between high and low BP groups were assessed with Mann-Whitney U tests. Results Gut microbiome composition explained 4.4% of systolic BP variance. Best predictors for systolic BP included Roseburia spp. (ρ −0.15, p&lt;0.001), Clostridium spp. (ρ −0.14, p&lt;0.001), Romboutsia spp. (ρ −0.10, p&lt;0.001), and Ruminococceae spp. (ρ −0.15, p&lt;0.001) (Figure 1). Explained variance of the microbiome composition was highest in Dutch subjects (4.8%), but very low in African Surinamese, Ghanaian, and Turkish ethnic groups (ranging from 0–0.77%) Hence, we selected only participants with Dutch ethnicity for the matched subgroup. Participants with high BP had lower abundance of Roseburia hominis (p&lt;0.01) and Roseburia spp. (p&lt;0.05) compared to participants with low BP. However, fecal acetate (p&lt;0.05) and propionate (p&lt;0.01) levels were higher in participants with high BP. Conclusions In this cross-sectional study, gut microbiome composition was moderately associated with BP. Associations were strongly divergent between ethnic groups, with strongest associations in Dutch participants. Intriguingly, while Dutch participants with high BP had lower abundances of several SCFA-producing microbes, they had higher fecal SCFA levels. Intervention studies with SCFAs could provide more insight in the effects of these metabolites on BP. Funding Acknowledgement Type of funding source: Public Institution(s). Main funding source(s): The Academic Medical Center (AMC) of Amsterdam and the Public Health Service of Amsterdam (GGD Amsterdam) provided core financial support for HELIUS. The HELIUS study is also funded by research grants of the Dutch Heart Foundation (Hartstichting; grant no. 2010T084), the Netherlands Organization for Health Research and Development (ZonMw; grant no. 200500003), the European Integration Fund (EIF; grant no. 2013EIF013) and the European Union (Seventh Framework Programme, FP-7; grant no. 278901).


Author(s):  
Ana Soriano-Lerma ◽  
María García-Burgos ◽  
María J.M. Alférez ◽  
Virginia Pérez-Carrasco ◽  
Victoria Sanchez-Martin ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document