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Nutrients Dec 2023A low carbohydrate, high fat (LCHF) diet in athletes increases fat oxidation but impairs sports performance, potentially due to impaired exercise economy. Dietary...
A low carbohydrate, high fat (LCHF) diet in athletes increases fat oxidation but impairs sports performance, potentially due to impaired exercise economy. Dietary nitrate supplementation can improve exercise economy via an increase in nitric oxide production, which is initiated by the reduction of nitrate to nitrite within the oral cavity. This reaction is dependent on the presence of nitrate-reducing oral bacteria, which can potentially be altered by dietary changes, including a LCHF diet. This study explored the effect of a LCHF diet on the oral microbiome and subsequent changes to plasma nitrite concentration following nitrate supplementation. Following five days of LCHF or high carbohydrate (HCHO) control dietary intervention, highly trained male race walkers consumed 140 mL beetroot juice containing 8.4 mmol nitrate; they then provided (a) blood samples for plasma nitrate and nitrite analysis and (b) saliva samples for 16S rRNA sequencing of the oral microbiome. The LCHF diet (n = 13) reduced oral bacterial diversity and changed the relative abundance of the genera (+10%), (+3%), (-9%), and (-4%), with no significant changes observed following the HCHO diet (n = 11). Following beetroot juice ingestion, plasma nitrite concentrations were higher for the LCHF diet compared to the HCHO diet ( = 0.04). However, the absence of an interaction with the trial (pre-post) ( = 0.71) suggests that this difference was not due to the dietary intervention. In summary, we found an increase in plasma nitrate and nitrite concentrations in response to nitrate supplementation independent of diet. This suggests the oral microbiome is adaptive to dietary changes and can maintain a nitrate reduction capacity despite a decrease in bacterial diversity following the LCHF diet.
Topics: Humans; Male; Nitrites; Diet, High-Fat; Nitrates; RNA, Ribosomal, 16S; Microbiota; Bacteria; Carbohydrates; Dietary Supplements; Beta vulgaris
PubMed: 38140382
DOI: 10.3390/nu15245123 -
Nutrients Dec 2023A "high-fat, high-energy diet" is commonly recommended for children with cystic fibrosis (CF), leading to negative consequences on dietary patterns that could contribute... (Observational Study)
Observational Study
A "high-fat, high-energy diet" is commonly recommended for children with cystic fibrosis (CF), leading to negative consequences on dietary patterns that could contribute to altered colonic microbiota. The aim of this study was to assess dietary intake and to identify possible associations with the composition of faecal microbiota in a cohort of children with CF. A cross-sectional observational study was conducted, including a 3-day food record simultaneously with the collection of faecal samples. The results showed a high fat intake (43.9% of total energy intake) and a mean dietary fibre intake of 10.6 g/day. The faecal microbiota was characterised at the phylum level as 54.5% Firmicutes and revealed an altered proportion between Proteobacteria (32%) and Bacteroidota (2.2%). Significant associations were found, including a negative association between protein, meat, and fish intake and Bifidobacterium, a positive association between lipids and and Streptococcus, a negative association between carbohydrates and and , and a positive association between total dietary fibre and and . The results reveal that a "high-fat, high-energy" diet does not satisfy dietary fibre intake from healthy food sources in children with CF. Further interventional studies are encouraged to explore the potential of shifting to a high-fibre or standard healthy diet to improve colonic microbiota.
Topics: Child; Animals; Humans; Diet; Cystic Fibrosis; Cross-Sectional Studies; Dietary Fiber; Diet, High-Fat; Microbiota; Eating
PubMed: 38140272
DOI: 10.3390/nu15245013 -
Journal of Sport and Health Science Sep 2024
Is Veillonella a unique marker of physical exercise? Commentary on: "Is physical performance (in mice) increased by Veillonella atypica or decreased by Lactobacillus bulgaricus?".
Topics: Animals; Mice; Lactobacillus delbrueckii; Physical Functional Performance; Exercise; Gastrointestinal Microbiome; Biomarkers; Physical Conditioning, Animal
PubMed: 38135273
DOI: 10.1016/j.jshs.2023.12.003 -
Frontiers in Microbiology 2023Gravel-mulched land in China suffers from poor natural resources and fragile ecological environment, posing a challenge to effective restoration of ecological function....
Gravel-mulched land in China suffers from poor natural resources and fragile ecological environment, posing a challenge to effective restoration of ecological function. a traditional Chinese herb used for treating human diseases, is a highly adaptable and resilient plant species, can effectively improve the soil properties, and may have important implications for the ecology and economy of gravel-mulched land. A study was conducted in a gravel-mulched field to measure the impact of planting the (including control (CK), 1-year, 2-year, and 4-year cultivation of plants) on (i) dynamic changes in soil nutrient and enzyme activity properties, and (ii) soil rhizosphere microbial community structure characteristics. We found that the concentration of soil organic carbon, available nitrogen, available phosphorus and available potassium in soil after cultivation for 1-4 years increased by 11-409%. The urease, phosphatase and catalase activities were increased by 11-560%, with the highest nutrient concentration and enzyme activity in 4-year plants. The pH value gradually decreased after cultivation. The improved soil environments increased soil bacterial community diversity. Planting significantly increased the bacterial ACE, Chao1 index, Simpson index, and Shannon-Wiener index. The , and were observed in dominant phyla. The relative abundance of eight genera, including , and , was significantly reduced by more than 1%. Taken together, these soil indicators suggest that planting in the short term would be a cost-effective strategy to combat soil degradation in a gravel-mulched ecosystem.
PubMed: 38130947
DOI: 10.3389/fmicb.2023.1225503 -
Journal of Oral Biology and... 2024Saliva, an oral secretion is considered an essential biological modulator involved in maintaining oral homeostasis. Increased glucose levels in diabetic patients' saliva...
BACKGROUND
Saliva, an oral secretion is considered an essential biological modulator involved in maintaining oral homeostasis. Increased glucose levels in diabetic patients' saliva may have an impact on diversity of microbes. Comparing the salivary microflora of diabetic and non-diabetic cohorts will help in diagnosis and risk assessment of oral health complications. This will provide greater knowledge about the contribution of oral microbes to the development of oral illnesses. The association between salivary microbiota and diabetic state is less explored in the North Indian population, hence current observational study was performed to analyze the salivary microflora of diabetic and non-diabetic individuals using metagenomic analysis.
MATERIALS AND METHODS
This single-center non-randomized observational trial was conducted in Uttar Pradesh, India. Participants were enrolled into either diabetic (n = 68) or non-diabetic groups (n = 68) based on their diabetes status. Following saliva collection, DNA was extracted and metagenomic sequencing was performed.
RESULTS
Phylum Bacteroidetes and Fusobacteria were significantly abundant in diabetic individuals (p < 0.0001), while Proteobacteria was significantly higher among non-diabetic individuals (p < 0.0001). No statistical difference in phylum Actinobacteria and Firmicutes among diabetics and non-diabetics. were greater in diabetics whereas the abundance of was more among non-diabetics (p < 0.05).
CONCLUSIONS
The genera and were comparatively over the odds with the diabetics in India. The association between microbiota in diabetic population and risk related to increase in occurrence of caries, gingivitis, and periodontitis in diabetic population prevalence should be investigated.
PubMed: 38130425
DOI: 10.1016/j.jobcr.2023.12.003 -
PloS One 2023The nitrate (NO3-) reducing bacteria resident in the oral cavity have been implicated as key mediators of nitric oxide (NO) homeostasis and human health. NO3--reducing... (Meta-Analysis)
Meta-Analysis
The nitrate (NO3-) reducing bacteria resident in the oral cavity have been implicated as key mediators of nitric oxide (NO) homeostasis and human health. NO3--reducing oral bacteria reduce inorganic dietary NO3- to nitrite (NO2-) via the NO3--NO2--NO pathway. Studies of oral NO3--reducing bacteria have typically sampled from either the tongue surface or saliva. The aim of this study was to assess whether other areas in the mouth could contain a physiologically relevant abundance of NO3- reducing bacteria, which may be important for sampling in clinical studies. The bacterial composition of seven oral sample types from 300 individuals were compared using a meta-analysis of the Human Microbiome Project data. This analysis revealed significant differences in the proportions of 20 well-established oral bacteria and highly abundant NO3--reducing bacteria across each oral site. The genera included Actinomyces, Brevibacillus, Campylobacter, Capnocytophaga, Corynebacterium, Eikenella, Fusobacterium, Granulicatella, Haemophilus, Leptotrichia, Microbacterium, Neisseria, Porphyromonas, Prevotella, Propionibacterium, Rothia, Selenomonas, Staphylococcus, Streptococcus and Veillonella. The highest proportion of NO3--reducing bacteria was observed in saliva, where eight of the bacterial genera were found in higher proportion than on the tongue dorsum, whilst the lowest proportions were found in the hard oral surfaces. Saliva also demonstrated higher intra-individual variability and bacterial diversity. This study provides new information on where samples should be taken in the oral cavity to assess the abundance of NO3--reducing bacteria. Taking saliva samples may benefit physiological studies, as saliva contained the highest abundance of NO3- reducing bacteria and is less invasive than other sampling methods. These results inform future studies coupling oral NO3--reducing bacteria research with physiological outcomes affecting human health.
Topics: Humans; Nitrates; Nitrogen Dioxide; Mouth; Bacteria; Saliva; Microbiota; Streptococcus
PubMed: 38127919
DOI: 10.1371/journal.pone.0295058 -
Frontiers in Cellular and Infection... 2023To characterize the lung microbiome in the bronchoalveolar lavage fluid (BALF) of patients with Antisynthetase Syndrome (ASSD) according to anti-Jo1 autoantibody...
AIM
To characterize the lung microbiome in the bronchoalveolar lavage fluid (BALF) of patients with Antisynthetase Syndrome (ASSD) according to anti-Jo1 autoantibody positivity and evaluate the correlation with differential cell count and other bacterial genera in BALF.
METHODS
We sequenced the 16S ribosomal RNA gene in the BALF of anti-Jo1-positive (JoP, n=6) and non-Jo1-positive (NJo, n=17) patients, and the differential cell count in BALF was evaluated. The Spearman's correlation was calculated for the quantitative variables and abundance of bacterial species.
RESULTS
The genus showed a significant decrease (p<0.01) in JoP (2.2%) in comparison to NJo (4.1%) patients. The correlation analysis showed several high (rho ≥ ± 0.7) and significant (p < 0.05) correlations. We analyzed the results obtained for the genera and other study variables. The JoP group showed that the abundance of had a high negative correlation with macrophages (rho = - 0.77) and a positive correlation with eosinophils (rho = 0.77), lymphocytes (rho = 0.77), and (rho = 1).
CONCLUSIONS
The lung microbiome in ASSD patients differs and may affect cell composition, contributing to lung damage mechanisms. The presence of anti-Jo1 autoantibodies showed a low abundance of . This genus had a strong and positive correlation with abundance and levels of eosinophils and lymphocytes, and it showed a strong negative correlation with the percentage of macrophages.
Topics: Humans; Lung; Myositis; Lung Diseases, Interstitial; Autoantibodies
PubMed: 38116136
DOI: 10.3389/fcimb.2023.1321315 -
Frontiers in Microbiology 2023Despite the growing body of evidence, the link between the gut microbiota and different types of tumors, such as colorectal, gastric, and liver cancer, is becoming more...
INTRODUCTION
Despite the growing body of evidence, the link between the gut microbiota and different types of tumors, such as colorectal, gastric, and liver cancer, is becoming more apparent. The gut microbiota can be used as a reference for evaluating various diseases, including cancer, and can also act as risk factors or preventive factors. However, the specific connection between the gut microbiota and the advancement of esophageal cancer has yet to be investigated. Therefore, the aim of this research is to clarify the possible causal influence of intestinal microorganisms on the vulnerability to esophageal cancer through the utilization of Mendelian randomization (MR) studies.
METHODS
In this study, we employed a two-sample Mendelian randomization approach to evaluate the unbiased causal association between 150 different gut microbiota types and the occurrence of esophageal cancer. Following the selection from the IEU GWAS database and SNP filtration, we utilized various MR statistical techniques on the suitable instrumental variables. These included IVW methods, employing inverse variance weighting. Additionally, we performed a range of sensitivity analyses to confirm the heterogeneity and pleiotropy of the instrumental variables, thus ensuring the reliability of the outcomes.
RESULTS
The increased likelihood of developing esophageal cancer is linked to the genetically predicted high levels of , and . Conversely, a decreased risk of esophageal cancer is associated with the high abundance of , and . No heterogeneity and pleiotropy were detected in the sensitivity analysis.
DISCUSSION
We found that 11 types of gut microbial communities are associated with esophageal cancer, thereby confirming that the gut microbiota plays a significant role in the path.
PubMed: 38107856
DOI: 10.3389/fmicb.2023.1286598 -
Frontiers in Cellular and Infection... 2023Recent studies have suggested a relationship between gut microbiota and non-alcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH). However, the...
BACKGROUND
Recent studies have suggested a relationship between gut microbiota and non-alcoholic fatty liver disease (NAFLD)/nonalcoholic steatohepatitis (NASH). However, the nature and direction of this potential causal relationship are still unclear. This study used two-sample Mendelian randomization (MR) to clarify the potential causal links.
METHODS
Summary-level Genome-Wide Association Studies (GWAS) statistical data for gut microbiota and NAFLD/NASH were obtained from MiBioGen and FinnGen respectively. The MR analyses were performed mainly using the inverse-variance weighted (IVW) method, with sensitivity analyses conducted to verify the robustness. Additionally, reverse MR analyses were performed to examine any potential reverse causal associations.
RESULTS
Our analysis, primarily based on the IVW method, strongly supports the existence of causal relationships between four microbial taxa and NAFLD, and four taxa with NASH. Specifically, associations were observed between Enterobacteriales ( =0.04), ( =0.04), ( =0.02), and ( =0.04) and increased risk of NAFLD. ( =0.03) and ( =0.04) could increase the risks of NASH while ( =0.04) and (=0.005) could decrease them. We also identified that NAFLD was found to potentially cause an increased abundance in ( =0.007) and ( =0.002). However, we found no evidence of reverse causation in the microbial taxa associations with NASH.
CONCLUSION
This study identified several specific gut microbiota that are causally related to NAFLD and NASH. Observations herein may provide promising theoretical groundwork for potential prevention and treatment strategies for NAFLD and its progression to NASH in future.
Topics: Humans; Non-alcoholic Fatty Liver Disease; Gastrointestinal Microbiome; Genome-Wide Association Study; Mendelian Randomization Analysis; Clostridiaceae; Clostridiales
PubMed: 38106475
DOI: 10.3389/fcimb.2023.1294826 -
Clinical and Experimental Rheumatology Dec 2023To describe the taxonomy of the microbiota in crevicular fluid of primary Sjögren's syndrome (pSS) patients, and evaluate its association with clinical/serological... (Observational Study)
Observational Study
OBJECTIVES
To describe the taxonomy of the microbiota in crevicular fluid of primary Sjögren's syndrome (pSS) patients, and evaluate its association with clinical/serological variables, and oral quality of life.
METHODS
Observational study that included 48 pSS without diabetes mellitus, no active neoplasia, no antibiotic use in the previous two weeks, and no current active infection. We registered demographics, oral/ocular sicca symptoms, parotid enlargement and anti-Ro/La serology. We assessed the non-stimulated whole salivary flow (NSWSF), the EULAR Sjögren's Syndrome Patient Reported Index (ESSPRI), and the Xerostomia-related Quality of Life Scale (XeQoLS). Two periodontists determined the presence of periodontal disease and collected crevicular fluid from 6 teeth using filter paper. Samples were frozen at -86°C until processing. We included 17 sex- and age-matched control subjects. Bacterial DNA was extracted from the crevicular fluid sample using a commercial kit. 16SrRNA V3-V4 region was sequenced using reversible adaptor technology. Sequences were pre-processed and analysed using QIIME2 and phyloseq software programs. Functionality profiles were predicted using the Tax4Fun2 package.
RESULTS
PSS patients had more bacteria of the genera Prevotella, Streptococcus, Veillonella, Fusobacterium, and Leptotrichia and fewer bacteria of the genus Selenomonas than controls. The pSS microbiota contained more genes encoding accessory secretory proteins. Microbiota also differed between patients with anti-Ro/La status, parotid gland enlargement, and periodontal disease severity, but did not correlate with NSWSF and XeQoLS.
CONCLUSIONS
The crevicular fluid microbiota of pSS patients and controls differed significantly, even in SSP patients depending on their serology, parotid gland enlargement, and periodontal disease status.
Topics: Humans; Sjogren's Syndrome; Quality of Life; Xerostomia; Microbiota; Periodontal Diseases
PubMed: 38079342
DOI: 10.55563/clinexprheumatol/k3vx8u