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BMJ Open Diabetes Research & Care Jun 2024Type 2 diabetes mellitus (T2DM) is associated with dysbiosis in the gut microbiota (MB). Individually, each medication appears to partially correct this. However, there...
INTRODUCTION
Type 2 diabetes mellitus (T2DM) is associated with dysbiosis in the gut microbiota (MB). Individually, each medication appears to partially correct this. However, there are no studies on the response of the MB to changes in A1c. Therefore, we investigated the MB's response to intensive glycemic control.
RESEARCH DESIGN AND METHODS
We studied two groups of patients with uncontrolled T2DM, one group with an A1c <9% (18 patients-G1) and another group with an A1c >9% (13 patients-G2), aiming for at least a 1% reduction in A1c. We collected A1c and fecal samples at baseline, 6, and 12 months. G1 achieved an average A1c reduction of 1.1%, while G2 a reduction of 3.13%.
RESULTS
G1's microbiota saw a decrease in Erysipelotrichaceae_UCG_003 and in Mollicutes order (both linked to metabolic syndrome and associated comorbidities). G2, despite having a more significant reduction in A1c, experienced an increase in the proinflammatory bacteria and , and only one beneficial genus, , increased, producer of butyrate.
CONCLUSION
Despite a notable A1c outcome, G2 could not restore its MB. This seeming resistance to change, leading to a persistent inflammation component found in G2, might be part of the "metabolic memory" in T2DM.
Topics: Humans; Dysbiosis; Diabetes Mellitus, Type 2; Gastrointestinal Microbiome; Male; Female; Middle Aged; Glycated Hemoglobin; Aged; Feces; Blood Glucose; Follow-Up Studies; Hypoglycemic Agents; Glycemic Control; Biomarkers; Prognosis
PubMed: 38937275
DOI: 10.1136/bmjdrc-2023-003964 -
International Journal of Molecular... Jun 2024This study aimed to investigate the gut microbiota composition in children with autism spectrum disorder (ASD) compared to neurotypical (NT) children, with a focus on...
Comprehensive Analysis of Gut Microbiota Composition and Functional Metabolism in Children with Autism Spectrum Disorder and Neurotypical Children: Implications for Sex-Based Differences and Metabolic Dysregulation.
This study aimed to investigate the gut microbiota composition in children with autism spectrum disorder (ASD) compared to neurotypical (NT) children, with a focus on identifying potential differences in gut bacteria between these groups. The microbiota was analyzed through the massive sequencing of region V3-V4 of the 16S RNA gene, utilizing DNA extracted from stool samples of participants. Our findings revealed no significant differences in the dominant bacterial phyla (Firmicutes, Bacteroidota, Actinobacteria, Proteobacteria, Verrucomicrobiota) between the ASD and NT groups. However, at the genus level, notable disparities were observed in the abundance of , , , and , all of which have been previously associated with ASD. Furthermore, a sex-based analysis unveiled additional discrepancies in gut microbiota composition. Specifically, three genera (, , ) exhibited variations between male and female groups in both ASD and NT cohorts. Particularly noteworthy was the exclusive presence of in females with ASD. Analysis of predicted metabolic pathways suggested an enrichment of pathways related to amine and polyamine degradation, as well as amino acid degradation in the ASD group. Conversely, pathways implicated in carbohydrate biosynthesis, degradation, and fermentation were found to be underrepresented. Despite the limitations of our study, including a relatively small sample size (30 ASD and 31 NT children) and the utilization of predicted metabolic pathways derived from 16S RNA gene analysis rather than metagenome sequencing, our findings contribute to the growing body of evidence suggesting a potential association between gut microbiota composition and ASD. Future research endeavors should focus on validating these findings with larger sample sizes and exploring the functional significance of these microbial differences in ASD. Additionally, there is a critical need for further investigations to elucidate sex differences in gut microbiota composition and their potential implications for ASD pathology and treatment.
Topics: Humans; Gastrointestinal Microbiome; Autism Spectrum Disorder; Female; Male; Child; RNA, Ribosomal, 16S; Bacteria; Feces; Child, Preschool; Sex Factors; Sex Characteristics; Metabolic Networks and Pathways
PubMed: 38928411
DOI: 10.3390/ijms25126701 -
Food Science & Nutrition Jun 2024The effect of low-FODMAPs diet on irritable bowel syndrome (IBS) in Western China has not been reported. We aimed to investigate the effect of low-FODMAPs diet on IBS...
The effect of low-FODMAPs diet on irritable bowel syndrome (IBS) in Western China has not been reported. We aimed to investigate the effect of low-FODMAPs diet on IBS patients in the area and whether low-FODMAPs diet-induced alterations of microbiota could be improved through probiotics. IBS patients were randomized to the control group, low-FODMAPs diet group, probiotics group, or combined group. IBS Symptom Severity Score questionnaire (IBS-SSS) and IBS Quality of Life Score questionnaire (IBS-QOL) were completed at baseline, 2 and 4 weeks to evaluate the severity of symptoms. Fresh feces were collected for analyses of gut microbiota and short-chain fatty acids at baseline and 4 weeks after intervention. Seventy-three patients were included in the per protocol analysis. After intervention, there was significant improvement in IBS-SSS in the low-FODMAPs group (37.5%, 44.2%), probiotics group (51.4%, 62.0%), and combined group (34.1%, 40.4%) at both 2 weeks and 4 weeks, compared with the baseline ( < .05). In the low-FODMAPs group, the abundance of several microbiota (, , etc.) was significantly decreased. Furthermore, after the supplementation of probiotics in the combined group, the abundance of Genus_, , , , , , and was significantly increased, which was associated with the improvements of symptoms score in the correlation analysis. Our study confirmed the effectiveness and safety of short-term low-FODMAPs diet in IBS symptoms based on the Chinese diet in Western China. The combination of low-FODMAPs and probiotics plays a beneficial role in gut microbiota in IBS.
PubMed: 38873474
DOI: 10.1002/fsn3.4057 -
New Microbes and New Infections Jun 2024
PubMed: 38799929
DOI: 10.1016/j.nmni.2024.101245 -
New Microbes and New Infections Jun 2024
PubMed: 38799905
DOI: 10.1016/j.nmni.2024.101246 -
Journal of Dairy Science May 2024Methane is a potent greenhouse gas produced during the ruminal fermentation and is associated with a loss of feed energy. Therefore, efforts to reduce methane emissions...
Methane is a potent greenhouse gas produced during the ruminal fermentation and is associated with a loss of feed energy. Therefore, efforts to reduce methane emissions have been ongoing in the last decades. Methane production is highly influenced by factors such as the ruminal microbiome and host genetics. Previous studies have proposed to use the ruminal microbiome to reduce long-term methane emissions, as ruminal microbiome composition is a moderately heritable trait and genetic improvement accumulates over time. Lactation stage is another important factor that might influence methane production but potential associations with the ruminal microbiome have not been evaluated previously. This study sought to examine the changes in ruminal microbiome over the lactation period of primiparous Holstein cows differing in methane intensity and estimate the heritability of the abundance of relevant microorganisms. Ruminal content samples from 349 primiparous Holstein cows with 14 - 378 d in milk were collected from May 2018 to June 2019. Methane intensity (MI) of each cow was calculated as methane concentration/milk yield. Up to 64 taxonomic features (TF) from 20 phyla had a significant differential abundance between cows with low and high MI early in lactation, 16 TF during mid lactation, and none late in lactation. Taxonomical features within the Firmicutes, Proteobacteria, Melainabacteria, Cyanobacteria, Bacteroidetes and Actinobacteria phyla were associated to low MI, whereas eukaryotic TF and those within the Euryarchaeota, Verrucomicrobia, Kiritimatiellaeota, Lentisphaerae phyla were associated to high MI. Out of the 60 TF that were found to be differentially abundant between early and late lactation in cows with low MI, 56 TF were also significant when cows with low and high MI were compared in the first third of the lactation. In general, microbes associated with low MI were more abundant early in lactation (e.g., Acidaminococcus, Aeromonas and Weimeria genera) and showed low to moderate heritabilities (0.03 to 0.33). These results suggest some potential to modulate the rumen microbiome composition through selective breeding for lower MI. Differences in the ruminal microbiome of cows with extreme MI levels likely result from variations in the ruminal physiology of these cows and were more noticeable early in lactation probably due to important interactions between the host phenotype and environmental factors associated to that period. Our results suggest that the ruminal microbiome evaluated early in lactation may be more precise for MI difference, and hence, this should be considered to optimize sampling periods to establish a reference population in genomic selection scenarios.
PubMed: 38788852
DOI: 10.3168/jds.2023-24552 -
Microbiome May 2024Left ventricular diastolic dysfunction (LVDD) is an important precursor of heart failure (HF), but little is known about its relationship with gut dysbiosis and...
BACKGROUND
Left ventricular diastolic dysfunction (LVDD) is an important precursor of heart failure (HF), but little is known about its relationship with gut dysbiosis and microbial-related metabolites. By leveraging the multi-omics data from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL), a study with population at high burden of LVDD, we aimed to characterize gut microbiota associated with LVDD and identify metabolite signatures of gut dysbiosis and incident LVDD.
RESULTS
We included up to 1996 Hispanic/Latino adults (mean age: 59.4 years; 67.1% female) with comprehensive echocardiography assessments, gut microbiome, and blood metabolome data. LVDD was defined through a composite criterion involving tissue Doppler assessment and left atrial volume index measurements. Among 1996 participants, 916 (45.9%) had prevalent LVDD, and 212 out of 594 participants without LVDD at baseline developed incident LVDD over a median 4.3 years of follow-up. Using multivariable-adjusted analysis of compositions of microbiomes (ANCOM-II) method, we identified 7 out of 512 dominant gut bacterial species (prevalence > 20%) associated with prevalent LVDD (FDR-q < 0.1), with inverse associations being found for Intestinimonas_massiliensis, Clostridium_phoceensis, and Bacteroide_coprocola and positive associations for Gardnerella_vaginali, Acidaminococcus_fermentans, Pseudomonas_aeruginosa, and Necropsobacter_massiliensis. Using multivariable adjusted linear regression, 220 out of 669 circulating metabolites with detection rate > 75% were associated with the identified LVDD-related bacterial species (FDR-q < 0.1), with the majority being linked to Intestinimonas_massiliensis, Clostridium_phoceensis, and Acidaminococcus_fermentans. Furthermore, 46 of these bacteria-associated metabolites, mostly glycerophospholipids, secondary bile acids, and amino acids, were associated with prevalent LVDD (FDR-q < 0.1), 21 of which were associated with incident LVDD (relative risk ranging from 0.81 [p = 0.001, for guanidinoacetate] to 1.25 [p = 9 × 10, for 1-stearoyl-2-arachidonoyl-GPE (18:0/20:4)]). The inclusion of these 21 bacterial-related metabolites significantly improved the prediction of incident LVDD compared with a traditional risk factor model (the area under the receiver operating characteristic curve [AUC] = 0.73 vs 0.70, p = 0.001). Metabolite-based proxy association analyses revealed the inverse associations of Intestinimonas_massilliensis and Clostridium_phoceensis and the positive association of Acidaminococcus_fermentans with incident LVDD.
CONCLUSION
In this study of US Hispanics/Latinos, we identified multiple gut bacteria and related metabolites linked to LVDD, suggesting their potential roles in this preclinical HF entity. Video Abstract.
Topics: Humans; Gastrointestinal Microbiome; Female; Middle Aged; Male; Hispanic or Latino; Ventricular Dysfunction, Left; United States; Dysbiosis; Aged; Bacteria; Metabolome; Echocardiography
PubMed: 38725043
DOI: 10.1186/s40168-024-01797-x -
International Journal of Molecular... Apr 2024Metabolic dysfunction-associated steatotic liver disease (MASLD) is a complex disorder whose prevalence is rapidly growing in South America. The disturbances in the...
Metabolic dysfunction-associated steatotic liver disease (MASLD) is a complex disorder whose prevalence is rapidly growing in South America. The disturbances in the microbiota-gut-liver axis impact the liver damaging processes toward fibrosis. Gut microbiota status is shaped by dietary and lifestyle factors, depending on geographic location. We aimed to identify microbial signatures in a group of Chilean MASLD patients. Forty subjects were recruited, including healthy controls (HCs), overweight/obese subjects (Ow/Ob), patients with MASLD without fibrosis (MASLD/F-), and MASLD with fibrosis (MASLD/F+). Both MASLD and fibrosis were detected through elastography and/or biopsy, and fecal microbiota were analyzed through deep sequencing. Despite no differences in α- and β-diversity among all groups, a higher abundance of and a lower presence of Defluviitaleaceae, Lachnospiraceae ND3007, and was found in MASLD/F- and MASLD/F+, compared to HC. Ruminococcaceae UCG-013 and were more abundant in MASLD/F+ than in Ow/Ob; both significantly differed between MASLD/F- and MASLD/F+, compared to HC. Significant positive correlations were observed between liver stiffness and , , , and abundance. Our results show that MASLD is associated with changes in bacterial taxa that are known to be involved in bile acid metabolism and SCFA production, with some of them being more specifically linked to fibrosis.
Topics: Humans; Gastrointestinal Microbiome; Male; Female; Middle Aged; Adult; Liver Cirrhosis; Feces; Liver; Fatty Liver; Disease Progression; Obesity; Chile; Bacteria; Aged
PubMed: 38673972
DOI: 10.3390/ijms25084387 -
Biomolecules Apr 2024In recent years, CRISPR-Cas toolboxes for editing have rapidly accelerated natural product discovery and engineering. However, Cas efficiencies are oftentimes...
In recent years, CRISPR-Cas toolboxes for editing have rapidly accelerated natural product discovery and engineering. However, Cas efficiencies are oftentimes strain-dependent, and the commonly used Cas9 (SpCas9) is notorious for having high levels of off-target toxicity effects. Thus, a variety of Cas proteins is required for greater flexibility of genetic manipulation within a wider range of strains. This study explored the first use of sp. Cas12j, a hypercompact Cas12 subfamily, for genome editing in and its potential in activating silent biosynthetic gene clusters (BGCs) to enhance natural product synthesis. While the editing efficiencies of Cas12j were not as high as previously reported efficiencies of Cas12a and Cas9, Cas12j exhibited higher transformation efficiencies compared to SpCas9. Furthermore, Cas12j demonstrated significantly improved editing efficiencies compared to Cas12a in activating BGCs in sp. A34053, a strain wherein both SpCas9 and Cas12a faced limitations in accessing the genome. Overall, this study expanded the repertoire of Cas proteins for genome editing in actinomycetes and highlighted not only the potential of recently characterized Cas12j in but also the importance of having an extensive genetic toolbox for improving the editing success of these beneficial microbes.
Topics: Streptomyces; Gene Editing; CRISPR-Cas Systems; Acidaminococcus; CRISPR-Associated Protein 9; Multigene Family; Bacterial Proteins; CRISPR-Associated Proteins; Genome, Bacterial
PubMed: 38672502
DOI: 10.3390/biom14040486 -
Research Square Apr 2024Latent tuberculosis infection (LTBI) is common in people living with HIV (PLHIV) in high TB burden settings. Active TB is associated with specific stool taxa; however,...
BACKGROUND
Latent tuberculosis infection (LTBI) is common in people living with HIV (PLHIV) in high TB burden settings. Active TB is associated with specific stool taxa; however, little is known about the stool microbiota and LTBI, including in PLHIV.
METHOD
Within a parent study that recruited adult females with HIV from Cape Town, South Africa into predefined age categories (18-25, 35-60 years), we characterised the stool microbiota of those with [interferon-γ release assay (IGRA)- and tuberculin skin test (TST)-positive] or without (IGRA- and TST- negative) LTBI (n=25 per group). 16S rRNA DNA sequences were analysed using QIIME2, Dirichlet Multinomial Mixtures, DESeq2 and PICRUSt2.
RESULTS
No α- or β-diversity differences occurred by LTBI status; however, LTBI-positives were depleted. Inferred metagenome data showed LTBI-negative-enriched pathways included several involved in methylglyoxal degradation, L-arginine, putrescine, 4-aminobutanoate degradation and L-arginine and ornithine degradation. Stool from LTBI-positives demonstrated differential taxa abundance based on a quantitative response to antigen stimulation (depletion associated with higher IGRA or TST responses, respectively). In LTBI-positives, older people had different β-diversities than younger people whereas, in LTBI-negatives, no differences occurred across age groups.
CONCLUSION
Amongst female PLHIV, those with LTBI had, vs. those without LTBI, Gemmiger-enriched, which are producers of short chain fatty acids. Taxonomic differences amongst people with LTBI occurred according to quantitative response to antigen stimulation and age. These data enhance our understanding of the microbiome's potential role in LTBI.
PubMed: 38645218
DOI: 10.21203/rs.3.rs-4182285/v1