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Nutrients Nov 2023The objective of this study was to examine the correlation between gut microbiota and both age-related macular degeneration (AMD) and glaucoma. Mendelian randomization...
The objective of this study was to examine the correlation between gut microbiota and both age-related macular degeneration (AMD) and glaucoma. Mendelian randomization studies were conducted utilizing the data sourced from the genome-wide association study (GWAS) database for the gut microbiome, AMD, and glaucoma. Single nucleotide polymorphism (SNP) estimates were summarized through five Mendelian randomization (MR) methods. We utilized Cochran's Q statistic to evaluate the heterogeneity of the instrumental variables (IVs). Additionally, we employed a "leave-one-out" approach to verify the stability of our findings. Inverse variance weighted (IVW) suggests that Eubacterium (oxidoreducens group) and Parabacteroides had a protective effect on AMD. Both weighted median and IVW suggest that Lachnospiraceae (NK4A136 group) and Ruminococcaceae (UCG009) had a protective effect on AMD. However, both weighted median and IVW suggest that Dorea had a risk effect on AMD. Similarly, The IVW of Eubacterium (ventriosum group) showed a risk effect on AMD. The weighted median of Eubacterium (nodatum group), Lachnospiraceae (NC2004 group), and Roseburia had a risk effect on glaucoma. IVW suggested that Ruminococcaceae (UCG004) had a risk effect on glaucoma. Reverse MR analysis found a causal link between Eubacterium (nodatum group) and glaucoma. No causal relationships were found between AMD or glaucoma and the other mentioned bacterial groups. No significant heterogeneity or evidence of horizontal pleiotropy was detected. This study found that certain gut bacteria had protective effects on AMD, while others may be risk factors for AMD or glaucoma. Likewise, reverse MR found that glaucoma led to an increased abundance of certain gut bacteria. Further trials are needed to clarify the specific mechanisms involved.
Topics: Humans; Gastrointestinal Microbiome; Genome-Wide Association Study; Mendelian Randomization Analysis; Glaucoma; Macular Degeneration; Clostridiales; Lactobacillales
PubMed: 37960299
DOI: 10.3390/nu15214646 -
Frontiers in Aging Neuroscience 2023Gut-brain axis might play an important role in cognitive impairments by various diseases including Alzheimer's disease (AD).
BACKGROUND
Gut-brain axis might play an important role in cognitive impairments by various diseases including Alzheimer's disease (AD).
OBJECTIVE
To investigate the differences in gut microbial composition, intestinal barrier function, and systemic inflammation in patients with AD or mild cognitive impairment (MCI), and normal control (NC) cases.
METHODS
A total of 118 subjects (45 AD, 38 MCI, and 35 NC) were recruited. Cognitive function was assessed using Mini-Mental State Examination (MMSE), and Montreal Cognitive Assessment Scale (MoCA). Functional ability was assessed using Activity of Daily Living Scale (ADL). The composition of gut microbiome was examined by 16S rRNA high-throughput sequencing. Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) was used to predict functional transfer of gut microbiota. Gut barrier dysfunction was evaluated by measuring the levels of diamine oxidase (DAO), D-lactic acid (DA), and endotoxin (ET). The serum high-sensitivity C-reactive protein (hs-CRP) level was used to indicate systemic inflammation.
RESULTS
Compared with normal controls, patients with cognitive impairments (AD and MCI) had lower abundance of and higher levels of DAO, DA, and ET. Kyoto Encyclopedia of Genes and Genomes (KEGG) results showed that the pathways related to glycan biosynthesis and metabolism increased in MCI patients, while the ones related to membrane transport decreased. The abundance of and was negatively correlated with the content of ET, and positively correlated with the scores of MMSE and MoCA. The hs-CRP levels were similar among the three groups. A significant negative correlation was observed between the severity of gut barrier dysfunction and cognitive function.
CONCLUSION
Cognitive impairments might be associated with gut microbial dysbiosis and intestinal barrier dysfunction.
PubMed: 37350810
DOI: 10.3389/fnagi.2023.1174599 -
BMC Microbiology Nov 2020The make-up of gut microbiota at different puberty stages has not been reported. This cross-sectional study analyzed the bio-diversity of gut microbiota at different...
BACKGROUND
The make-up of gut microbiota at different puberty stages has not been reported. This cross-sectional study analyzed the bio-diversity of gut microbiota at different puberty stages.
RESULT
The subjects (aged 5-15 years) were divided into non-pubertal (n = 42, male%: 66.7%) or pubertal groups (n = 47, male%:44.68); in both groups, Firmicutes, Bacteroidetes and Proteobacteria were the dominant phylum. There was no difference of alpha- and beta-diversity among disparate puberty stages. Non-pubertal subjects had members of the order Clostridiales, family Clostridiaceae, genus Coprobacillus which were significantly more prevalent than puberty subjects. Also, the pubertal subjects had members of class Betaproteobacteria, order Burkholderiales which were significantly more prevalent than the non-pubertal subjects. Their relative abundance was independent of BMI-Z. In the pubertal subjects, the abundance of genus Adlercreutzia, Ruminococcus, Dorea, Clostridium and Parabacteroides was associated with the level of testosterone.
CONCLUSIONS
This is the first report of the diversity of gut microbiota at different puberty stages. The various species of gut microbiota changed gradually associated with puberty stages. Differences in gut microflora at different pubertal status may be related to androgen levels.
Topics: Adolescent; Bacteria; Child; Child, Preschool; Cross-Sectional Studies; Female; Gastrointestinal Microbiome; Humans; Male; Puberty; RNA, Ribosomal, 16S; Testosterone
PubMed: 33143658
DOI: 10.1186/s12866-020-02021-0 -
European Journal of Nuclear Medicine... Apr 2023Radioactive iodine (I) therapy is a conventional post-surgery treatment widely used for papillary thyroid carcinoma (PTC). Since I is orally administered, we hypothesize...
PURPOSE
Radioactive iodine (I) therapy is a conventional post-surgery treatment widely used for papillary thyroid carcinoma (PTC). Since I is orally administered, we hypothesize that it may affect gut microbiome. This study aims to investigate alterations of intestinal microbiome caused by I therapy in PTC patients and explore its association with response to I therapy.
METHODS
Fecal samples of 60 PTC patients pre- and post-I therapy were collected to characterize the I therapy-induced gut microbiota alterations using 16S rRNA gene sequencing. According to the inclusion criteria, sequence data of 40 out of the 60 patients, divided into excellent response (ER) group and non-excellent response (NER) group, were recruited to investigate the possible connection between gut microbiota and response to I therapy. Multivariate binary logistic regression was employed to construct a predictive model for response to I therapy.
RESULTS
Microbial richness, diversity, and composition were tremendously altered by I therapy. A significant decline of Firmicutes to Bacteroides (F/B) ratio was observed post-I therapy. I therapy also led to changes of gut microbiome-related metabolic pathways. Discrepancies in β diversity were found between ER and NER groups both pre- and post-I therapy. Furthermore, a predictive model for response to I therapy with a p value of 0.003 and an overall percentage correct of 80.0% was established, with three variables including lymph node metastasis, relative abundance of g_Bifidobacterium and g_Dorea. Among them, g_Dorea was identified to be an in independent predictor of response to I therapy (p = 0.04).
CONCLUSION
For the first time, the present study demonstrates the gut microbial dysbiosis caused by I therapy in post-surgery PTC patients and reveals a previously undefined role of gut microbiome as predictor for I ablation response. G_Dorea and g_Bifidobacterium may be potential targets for clinical intervention to improve response to I in post-operative PTC patients.
TRIAL REGISTRATION
ChiCTR2100048000. Registered 28 June 2021.
Topics: Humans; Gastrointestinal Microbiome; Iodine Radioisotopes; Thyroid Cancer, Papillary; RNA, Ribosomal, 16S; Thyroid Neoplasms
PubMed: 36512067
DOI: 10.1007/s00259-022-06072-5 -
Pathogens (Basel, Switzerland) Jul 2022is an anaerobic Gram-positive and spore-forming bacterium. The majority of strains produce two toxins, A and B, associated with the development of acute diarrhea... (Review)
Review
is an anaerobic Gram-positive and spore-forming bacterium. The majority of strains produce two toxins, A and B, associated with the development of acute diarrhea and/or colitis. In this review, two situations are distinguished: infection (CDI) and asymptomatic colonization (AC). The main objective of this review is to explore the available data related to the link between the gut microbiota and the development of CDI. The secondary aim is to provide more information on why some people colonized with toxigenic develop an infection while others show no signs of disease. Several factors, such as the use of antibiotics and proton pump inhibitors, hospitalization, and age, predispose individuals to colonization and/or infection. The gut microbiota of people with AC showed decreased abundances of , , , , , , and . The gut microbiota of people suffering from CDI showed reductions in the abundances of , , spp., spp., spp., spp., spp., spp., spp. and spp., in comparison with healthy people. Furthermore, increases in the abundances of and were associated with infection.
PubMed: 35890026
DOI: 10.3390/pathogens11070781 -
Nutrients Feb 2023Roux-en-Y Gastric bypass (RYGB) promotes improvement in type 2 diabetes (T2D) shortly after surgery, with metabolic mechanisms yet to be elucidated. This study aimed to...
Roux-en-Y Gastric bypass (RYGB) promotes improvement in type 2 diabetes (T2D) shortly after surgery, with metabolic mechanisms yet to be elucidated. This study aimed to investigate the relationship between food intake, tryptophan metabolism, and gut microbiota on the glycemic control of obese T2D women after RYGB surgery. Twenty T2D women who underwent RYGB were evaluated before and three months after surgery. Food intake data were obtained by a seven-day food record and a food frequency questionnaire. Tryptophan metabolites were determined by untargeted metabolomic analysis, and the gut microbiota was determined by 16S rRNA sequencing. The glycemic outcomes were fasting blood glucose, HbA1C, HOMA-IR, and HOMA-beta. Linear regression models were applied to assess the associations between the changes in food intake, tryptophan metabolism, and gut microbiota on glycemic control after RYGB. All variables changed after RYGB ( < 0.05), except for tryptophan intake. Jointly, the variation in red meat intake, plasma indole-3-acetate, and was associated with postoperative HOMA-IR {R 0.80, R adj 0.74; < 0.01}. Red meat intake decreased three months after bariatric surgery while indole-3-acetate and increased in the same period. These combined variables were associated with better insulin resistance in T2D women after RYGB.
Topics: Humans; Female; Gastric Bypass; Insulin Resistance; Diabetes Mellitus, Type 2; RNA, Ribosomal, 16S; Tryptophan; Red Meat; Acetates; Indoles; Blood Glucose; Insulin; Obesity, Morbid
PubMed: 36904185
DOI: 10.3390/nu15051185 -
Biomolecules Aug 2021Manganese (Mn) is an essential metal, which at high exposures causes neurotoxic effects and neurodegeneration. The neurotoxic effects of Mn are mediated by... (Review)
Review
Manganese (Mn) is an essential metal, which at high exposures causes neurotoxic effects and neurodegeneration. The neurotoxic effects of Mn are mediated by neuroinflammation, oxidative and endoplasmic reticulum stress, mitochondrial dysfunction, and other mechanisms. Recent findings have demonstrated the potential impact of Mn overexposure on gut microbiota dysbiosis, which is known to contribute to neurodegeneration via secretion of neuroactive and proinflammatory metabolites. Therefore, in this review, we discuss the existing data on the impact of Mn exposure on gut microbiota biodiversity, bacterial metabolite production, and gut wall permeability regulating systemic levels. Recent data have demonstrated that Mn exposure may affect gut microbiota biodiversity by altering the abundance of Shiegella, Ruminococcus, Dorea, Fusicatenibacter, Roseburia, Parabacteroides, Bacteroidetes, Firmicutes, Ruminococcaceae, Streptococcaceae, and other bacterial phyla. A Mn-induced increase in Bacteroidetes abundance and a reduced Firmicutes/Bacteroidetes ratio may increase lipopolysaccharide levels. Moreover, in addition to increased systemic lipopolysaccharide (LPS) levels, Mn is capable of potentiating LPS neurotoxicity. Due to the high metabolic activity of intestinal microflora, Mn-induced perturbations in gut microbiota result in a significant alteration in the gut metabolome that has the potential to at least partially mediate the biological effects of Mn overexposure. At the same time, a recent study demonstrated that healthy microbiome transplantation alleviates Mn-induced neurotoxicity, which is indicative of the significant role of gut microflora in the cascade of Mn-mediated neurotoxicity. High doses of Mn may cause enterocyte toxicity and affect gut wall integrity through disruption of tight junctions. The resulting increase in gut wall permeability further promotes increased translocation of LPS and neuroactive bacterial metabolites to the systemic blood flow, ultimately gaining access to the brain and leading to neuroinflammation and neurotransmitter imbalance. Therefore, the existing data lead us to hypothesize that gut microbiota should be considered as a potential target of Mn toxicity, although more detailed studies are required to characterize the interplay between Mn exposure and the gut, as well as its role in the pathogenesis of neurodegeneration and other diseases.
Topics: Animals; Gastrointestinal Microbiome; Humans; Immunity; Manganese; Metabolome; Nerve Degeneration; Neurotoxins
PubMed: 34572505
DOI: 10.3390/biom11091292 -
Biomolecules May 2021Hypertriglyceridemia-associated acute pancreatitis (HTGAP) is linked with increased severity and morbidity. Intestinal flora plays an important role in the progression... (Observational Study)
Observational Study
Hypertriglyceridemia-associated acute pancreatitis (HTGAP) is linked with increased severity and morbidity. Intestinal flora plays an important role in the progression of acute pancreatitis (AP). However, pathogenetic association between gut microbiota and HTGAP remains unknown. In this study, we enrolled 30 HTGAP patients and 30 patients with AP that is evoked by other causes. The V3-V4 regions of 16S rRNA sequences of the gut microbiota were analyzed. Clinical characteristics, microbial diversity, taxonomic profile, microbiome composition, microbiological phenotype, and functional pathways were compared between the two groups. Our results showed that the HTGAP group had a higher proportion of severe AP (46.7% vs. 20.0%), organ failure (56.7% vs. 30.0%), and a longer hospital stay (18.0 days vs. 6.5 days). HTGAP group also had poorer microbial diversity, higher abundances of and , but lower abundances of , , and as compared with non-HTGAP group. Correlation analysis revealed that gut bacterial taxonomic and functional changes were linked with local and systemic complications, ICU admission, and mortality. This study revealed that alterations of gut microbiota were associated with disease severity and poor prognosis in HTGAP patients, indicating a potential pathophysiological link between gut microbiota and hypertriglyceridemia related acute pancreatitis.
Topics: Adult; Aged; Bacteria; DNA, Bacterial; DNA, Ribosomal; Female; Gastrointestinal Microbiome; Humans; Hypertriglyceridemia; Length of Stay; Male; Middle Aged; Pancreatitis; Phylogeny; Prognosis; Prospective Studies; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Severity of Illness Index
PubMed: 34066441
DOI: 10.3390/biom11050695 -
Microorganisms Jul 2023A cross-sectional study involving 224 healthy Japanese adult females explored the relationship between ramen intake, gut microbiota diversity, and blood biochemistry....
A cross-sectional study involving 224 healthy Japanese adult females explored the relationship between ramen intake, gut microbiota diversity, and blood biochemistry. Using a stepwise regression model, ramen intake was inversely associated with gut microbiome alpha diversity after adjusting for related factors, including diets, Age, BMI, and stool habits (β = -0.018; r = -0.15 for Shannon index). The intake group of ramen was inversely associated with dietary nutrients and dietary fiber compared with the no-intake group of ramen. Sugar intake, as a short-chain fatty acid (SCFA)-producing gut microbiota, and γ-glutamyl transferase as a liver function marker were directly associated with ramen intake after adjustment for related factors including diets, gut microbiota, and blood chemistry using a stepwise logistic regression model, whereas is inconsistently less abundant in the ramen group. In conclusion, the increased ramen was associated with decreased gut bacterial diversity accompanying a perturbation of through the dietary nutrients, gut microbiota, and blood chemistry, while the methodological limitations existed in a cross-sectional study. People with frequent ramen eating habits need to take measures to consume various nutrients to maintain and improve their health, and dietary management can be applied to the dietary feature in ramen consumption.
PubMed: 37630452
DOI: 10.3390/microorganisms11081892 -
Frontiers in Immunology 2023Nicotine dependence is a key factor influencing the diversity of gut microbiota, and targeting gut microbiota may become a new approach for the prevention and treatment...
BACKGROUND
Nicotine dependence is a key factor influencing the diversity of gut microbiota, and targeting gut microbiota may become a new approach for the prevention and treatment of nicotine dependence. However, the causal relationship between the two is still unclear. This study aims to investigate the causal relationship between nicotine dependence and gut microbiota.
METHODS
A two-sample bidirectional Mendelian randomization (MR) study was conducted using the largest existing gut microbiota and nicotine dependence genome-wide association studies (GWAS). Causal relationships between genetically predicted nicotine dependence and gut microbiota abundance were examined using inverse variance weighted, MR-Egger, weighted median, simple mode, weighted mode, and MR-PRESSO approaches. Cochrane's Q test, MR-Egger intercept test, and leave-one-out analysis were performed as sensitivity analyses to assess the robustness of the results. Multivariable Mendelian randomization analysis was also conducted to eliminate the interference of smoking-related phenotypes. Reverse Mendelian randomization analysis was then performed to determine the causal relationship between genetically predicted gut microbiota abundance and nicotine dependence.
RESULTS
Genetically predicted nicotine dependence had a causal effect on (β: -0.52, 95% CI: -0.934-0.106, P = 0.014). The group (OR: 1.106, 95% CI: 1.004-1.218), (OR: 1.118, 95% CI: 1.001-1.249) and (OR: 1.08, 95% CI: 1.001-1.167) were risk factors for nicotine dependence. (OR: 0.905, 95% CI: 0.837-0.977), (OR: 0.014, 95% CI: 0.819-0.977), (OR: 0.841, 95% CI. 0.731-0.968), (OR: 0.831, 95% CI: 0.735-0.939) and (OR: 0.838, 95% CI: 0.739-0.951) were protective factor for nicotine dependence. The sensitivity analysis showed consistent results.
CONCLUSION
The Mendelian randomization study confirmed the causal link between genetically predicted risk of nicotine dependence and genetically predicted abundance of gut microbiota. Gut microbiota may serve as a biomarker and offer insights for addressing nicotine dependence.
Topics: Humans; Tobacco Use Disorder; Gastrointestinal Microbiome; Genome-Wide Association Study; Mendelian Randomization Analysis; Smoking; Clostridiales
PubMed: 38022531
DOI: 10.3389/fimmu.2023.1244272