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The Effect of Oral Iron Supplementation on Gut Microbial Composition: a Secondary Analysis of a Double-Blind, Randomized Controlled Trial among Cambodian Women of Reproductive Age.
Finlayson-Trick, E, Nearing, J, Fischer, JA, Ma, Y, Wang, S, Krouen, H, Goldfarb, DM, Karakochuk, CD
Microbiology spectrum. 2023;11(3):e0527322
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Iron supplementation is recommended for all women of reproductive age in Cambodia, where anaemia has a high prevalence. The gut microbiome contains iron-dependent bacteria with the potential to cause intestinal disease (enteropathogens). The aim of this study was to examine changes in the gut microbiome following 12 weeks of daily supplementation of either ferrous sulfate or ferrous bisglycinate in non-pregnant Cambodian women of reproductive age. This study was nested within a larger randomised controlled trial of oral iron supplementation that included 480 non-pregnant Cambodian women. The participants were randomised at a 1:1:1 allocation ratio to either ferrous sulfate, ferrous bisglycinate, or placebo. Results showed that daily iron supplementation did not significantly affect gut bacterial diversity. However, iron supplementation, in the form of ferrous bisglycinate, increases the relative abundance of Enterobacteriaceae. Authors conclude that their findings can facilitate future research that may inform evidence-based global practice and policy.
Abstract
The World Health Organization recommends untargeted iron supplementation for women of reproductive age (WRA) in countries where anemia prevalence is greater than 40%, such as Cambodia. Iron supplements, however, often have poor bioavailability, so the majority remains unabsorbed in the colon. The gut houses many iron-dependent bacterial enteropathogens; thus, providing iron to individuals may be more harmful than helpful. We examined the effects of two oral iron supplements with differing bioavailability on the gut microbiomes in Cambodian WRA. This study is a secondary analysis of a double-blind, randomized controlled trial of oral iron supplementation in Cambodian WRA. For 12 weeks, participants received ferrous sulfate, ferrous bisglycinate, or placebo. Participants provided stool samples at baseline and 12 weeks. A subset of stool samples (n = 172), representing the three groups, were randomly selected for gut microbial analysis by 16S rRNA gene sequencing and targeted real-time PCR (qPCR). At baseline, 1% of women had iron-deficiency anemia. The most abundant gut phyla were Bacteroidota (45.7%) and Firmicutes (42.1%). Iron supplementation did not alter gut microbial diversity. Ferrous bisglycinate increased the relative abundance of Enterobacteriaceae, and there was a trend towards an increase in the relative abundance of Escherichia-Shigella. qPCR detected an increase in the enteropathogenic Escherichia coli (EPEC) virulence gene, bfpA, in the group that received ferrous sulfate. Thus, iron supplementation did not affect overall gut bacterial diversity in predominantly iron-replete Cambodian WRA, however, evidence does suggest an increase in relative abundance within the broad family Enterobacteriaceae associated with ferrous bisglycinate use. IMPORTANCE To the best of our knowledge, this is the first published study to characterize the effects of oral iron supplementation on the gut microbiomes of Cambodian WRA. Our study found that iron supplementation with ferrous bisglycinate increases the relative abundance of Enterobacteriaceae, which is a family of bacteria that includes many Gram-negative enteric pathogens like Salmonella, Shigella, and Escherichia coli. Using qPCR for additional analysis, we were able to detect genes associated with enteropathogenic E. coli, a type of diarrheagenic E. coli known to be present around the world, including water systems in Cambodia. The current WHO guidelines recommend blanket (untargeted) iron supplementation for Cambodian WRA despite a lack of studies in this population examining iron's effect on the gut microbiome. This study can facilitate future research that may inform evidence-based global practice and policy.
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The Short-Term Variation of Human Gut Mycobiome in Response to Dietary Intervention of Different Macronutrient Distributions.
Tian, Y, Gou, W, Ma, Y, Shuai, M, Liang, X, Fu, Y, Zheng, JS
Nutrients. 2023;15(9)
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The human gut is inhabited by a diverse and complex community of microbes, such as bacteria, viruses, and fungi, which are critical in maintaining human health. Gut mycobiome is less diverse and abundant than bacteria in the gut, which comprises approximately 0.1% of the total gut microbes and inhabits symbiotically with bacteria as a commensal in the human gut. The aim of this study was to explore short-term gut mycobiome variations in response to a high-carbohydrate, low-fat (HC) diet and a low-carbohydrate, high-fat (LC) diet. This study was a cross-over N-of-1 feeding trial among 30 participants over 72 days (WE-MACNUTR). A total of 28 participants were included in the final analysis. Results showed that the HC diet, but not the LC diet, may increase the fungal alpha diversity at the populational level. Both dietary interventions may affect the gut fungal community structure (i.e., beta diversity). Furthermore, the dietary environment influenced the relationship between gut mycobiome and glycaemic phenotypes. Authors concluded that their findings provide novel evidence on how the gut mycobiome structure and composition change in response to the HC and LC dietary interventions and reveals diet-specific changes in the fungal genera.
Abstract
While the human gut is home to a complex and diverse community of microbes, including bacteria and fungi, research on the gut microbiome has largely focused on bacteria, with relatively little attention given to the gut mycobiome. This study aims to investigate how diets with different dietary macronutrient distributions impact the gut mycobiome. We investigated gut mycobiome response to high-carbohydrate, low-fat (HC) and low-carbohydrate high-fat (LC) diet interventions based on a series of 72-day feeding-based n-of-1 clinical trials. A total of 30 participants were enrolled and underwent three sets of HC and LC dietary interventions in a randomized sequence. Each set lasted for 24 days with a 6-day washout period between dietary interventions. We collected and analyzed the fungal composition of 317 stool samples before and after each intervention period. To account for intra-individual variation across the three sets, we averaged the mycobiome data from the repeated sets for analysis. Of the 30 participants, 28 (aged 22-34 years) completed the entire intervention. Our results revealed a significant increase in gut fungal alpha diversity (p < 0.05) and significant changes in fungal composition (beta diversity, p < 0.05) after the HC dietary intervention. Specifically, we observed the enrichment of five fungal genera (Pleurotus, Kazachstania, Auricularia, Paraphaeosphaeria, Ustilaginaceae sp.; FDR < 0.052) and depletion of one fungal genus (Blumeria; FDR = 0.03) after the HC intervention. After the LC dietary intervention, one fungal genus was enriched (Ustilaginaceae sp.; FDR = 0.003), and five fungal genera were depleted (Blumeria, Agaricomycetes spp., Malassezia, Rhizopus, and Penicillium; FDR < 0.1). This study provides novel evidence on how the gut mycobiome structure and composition change in response to the HC and LC dietary interventions and reveals diet-specific changes in the fungal genera.
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The NADPARK study: A randomized phase I trial of nicotinamide riboside supplementation in Parkinson's disease.
Brakedal, B, Dölle, C, Riemer, F, Ma, Y, Nido, GS, Skeie, GO, Craven, AR, Schwarzlmüller, T, Brekke, N, Diab, J, et al
Cell metabolism. 2022;34(3):396-407.e6
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Parkinson’s disease (PD) is a major cause of death and disability, and current treatments can provide partial symptomatic relief, mainly for motor symptoms but make no substantial impact on disease progression. A growing body of evidence supports that boosting cellular levels of nicotinamide adenine dinucleotide (NAD) may confer neuroprotective effects in both healthy aging and neurodegeneration. The primary aim of this study was to assess penetration and metabolic responses of the brain to nicotinamide riboside (NR) supplementation in patients with PD. This study is a double-blinded, randomised, placebo-controlled phase I study of NR in newly diagnosed PD patients, naïve to dopaminergic therapy. Participants (n=30) where randomly assigned (1:1) to one of the two groups: NR group or placebo group. Results show that: - oral NR therapy increases brain NAD levels and impacts cerebral metabolism in PD. - supplementation with NR may target multiple processes implicated in the pathophysiology of the disease by upregulating the expression of genes involved in mitochondrial respiration, oxidative damage response, lysosomal and proteasomal function and downregulating inflammatory cytokines in the central nervous system. Authors conclude that NR can be a potential neuroprotective agent against PD. However, further investigation in a larger trial is required to warrant these findings.
Abstract
We conducted a double-blinded phase I clinical trial to establish whether nicotinamide adenine dinucleotide (NAD) replenishment therapy, via oral intake of nicotinamide riboside (NR), is safe, augments cerebral NAD levels, and impacts cerebral metabolism in Parkinson's disease (PD). Thirty newly diagnosed, treatment-naive patients received 1,000 mg NR or placebo for 30 days. NR treatment was well tolerated and led to a significant, but variable, increase in cerebral NAD levels-measured by 31phosphorous magnetic resonance spectroscopy-and related metabolites in the cerebrospinal fluid. NR recipients showing increased brain NAD levels exhibited altered cerebral metabolism, measured by 18fluoro-deoxyglucose positron emission tomography, and this was associated with mild clinical improvement. NR augmented the NAD metabolome and induced transcriptional upregulation of processes related to mitochondrial, lysosomal, and proteasomal function in blood cells and/or skeletal muscle. Furthermore, NR decreased the levels of inflammatory cytokines in serum and cerebrospinal fluid. Our findings nominate NR as a potential neuroprotective therapy for PD, warranting further investigation in larger trials.
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Effect of Lactobacillus casei on lipid metabolism and intestinal microflora in patients with alcoholic liver injury.
Li, X, Liu, Y, Guo, X, Ma, Y, Zhang, H, Liang, H
European journal of clinical nutrition. 2021;75(8):1227-1236
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Alcoholic liver disease (ALD) is a series of liver diseases caused by long-term heavy drinking. Lipid metabolism disorder often occurs in people with alcoholic liver injury. Treatment is mainly a combination of alcohol abstinence, improving nutrition, treating the liver injury, and preventing or reversing the progress of liver fibrosis or promoting liver regeneration. The aim of this study was to investigate the effect of Lactobacillus casei on lipid metabolism and intestinal microflora in patients with alcoholic liver injury. This study was a randomised, double-blind, placebo-controlled trial. A total of 181 ALD patients were recruited and randomly assigned to one of the three groups; low-dose group, high-dose group and positive control group (+ there was another group of 20 healthy people which served as normal control group). Results showed disorder of lipid metabolism, intestinal flora imbalance and inflammation in patients with alcoholic liver injury. Furthermore, after supplementation of Lactobacillus casei, there was a significant increase in the amount of Lactobacillus and Bifidobacterium. Authors conclude that Lactobacillus casei supplementation can improve lipid metabolism and regulate intestinal flora disorders in patients with alcoholic liver injury.
Abstract
BACKGROUND The present study aims to investigate the effect of Lactobacillus casei on lipid metabolism and intestinal microflora in patients with alcoholic liver injury. METHODS In a double-blind randomized controlled trial, 158 recruited alcoholic liver injury patients were randomized to three treatments for 60 days: low-dose group (LP, n = 58, 100 ml of Lactobacillus casei strain Shirota (LcS)), high-dose group (HP, n = 54, 200 ml of LcS), and positive control group (PC, n = 46, 100 ml of special drinks without active Lactobacillus casei). Another group of 20 healthy people was served as normal control group (NC). RESULTS The serum levels of TG and LDLC in the HP group were significantly decreased by 26.56% and 23.83%, respectively than those in the PC group (P < 0.05). After supplementation of Lactobacillus casei, there was a significant increase in the amount of Lactobacillus and Bifidobacterium when compared with the PC group (P < 0.05). CONCLUSIONS Supplementation of Lactobacillus casei can improve lipid metabolism and regulate intestinal flora disorders in patients with alcoholic liver injury.
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Fasting blood glucose at admission is an independent predictor for 28-day mortality in patients with COVID-19 without previous diagnosis of diabetes: a multi-centre retrospective study.
Wang, S, Ma, P, Zhang, S, Song, S, Wang, Z, Ma, Y, Xu, J, Wu, F, Duan, L, Yin, Z, et al
Diabetologia. 2020;63(10):2102-2111
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Hyperglycaemia was a risk factor for mortality from severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) and is an independent risk factor for lower respiratory tract infection and poor prognosis. The aim of this retrospective study of 605 patients without previously diagnosed diabetes was to examine the association between fasting blood glucose (FBG) on admission and the 28-day in hospital mortality of COVID-19 patients. Patients with a FBG level of 7.0mmol/l or over had more than double the risk of dying than those with a level of 6.0mmol/l or less. Other risk factors for mortality included age, being male, and severity of pneumonia at admission. Compared with patients whose FBG was 6.0mmol/l or lower at admission, patients with FBG of 7.0 mmol/l and above had a 3.99 times higher risk of in-hospital complications, whilst those with FBG of 6.1–6.9 mmol/l had a 2.61 times higher risk of complications. The authors conclude that glycaemic testing and control are important to all COVID-19 patients even where they have no pre-existing diabetes.
Abstract
AIMS/HYPOTHESIS Hyperglycaemia is associated with an elevated risk of mortality in community-acquired pneumonia, stroke, acute myocardial infarction, trauma and surgery, among other conditions. In this study, we examined the relationship between fasting blood glucose (FBG) and 28-day mortality in coronavirus disease 2019 (COVID-19) patients not previously diagnosed as having diabetes. METHODS We conducted a retrospective study involving all consecutive COVID-19 patients with a definitive 28-day outcome and FBG measurement at admission from 24 January 2020 to 10 February 2020 in two hospitals based in Wuhan, China. Demographic and clinical data, 28-day outcomes, in-hospital complications and CRB-65 scores of COVID-19 patients in the two hospitals were analysed. CRB-65 is an effective measure for assessing the severity of pneumonia and is based on four indicators, i.e. confusion, respiratory rate (>30/min), systolic blood pressure (≤90 mmHg) or diastolic blood pressure (≤60 mmHg), and age (≥65 years). RESULTS Six hundred and five COVID-19 patients were enrolled, including 114 who died in hospital. Multivariable Cox regression analysis showed that age (HR 1.02 [95% CI 1.00, 1.04]), male sex (HR 1.75 [95% CI 1.17, 2.60]), CRB-65 score 1-2 (HR 2.68 [95% CI 1.56, 4.59]), CRB-65 score 3-4 (HR 5.25 [95% CI 2.05, 13.43]) and FBG ≥7.0 mmol/l (HR 2.30 [95% CI 1.49, 3.55]) were independent predictors for 28-day mortality. The OR for 28-day in-hospital complications in those with FBG ≥7.0 mmol/l and 6.1-6.9 mmol/l vs <6.1 mmol/l was 3.99 (95% CI 2.71, 5.88) or 2.61 (95% CI 1.64, 4.41), respectively. CONCLUSIONS/INTERPRETATION FBG ≥7.0 mmol/l at admission is an independent predictor for 28-day mortality in patients with COVID-19 without previous diagnosis of diabetes. Glycaemic testing and control are important to all COVID-19 patients even where they have no pre-existing diabetes, as most COVID-19 patients are prone to glucose metabolic disorders. Graphical abstract.
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The Association between Breakfast Skipping and Body Weight, Nutrient Intake, and Metabolic Measures among Participants with Metabolic Syndrome.
Zhang, L, Cordeiro, LS, Liu, J, Ma, Y
Nutrients. 2017;9(4)
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There is conflicting evidence on the benefits of either skipping breakfast versus the idea that breakfast is the most important meal of the day. This study examines the effects of skipping breakfast on weight loss in a group of 240 participants diagnosed as having Metabolic syndrome (MetS). The study looked at data from a diet trial looking at the effects of a high fibre diet or the American Heart Association diet on MetS, in which they all also monitored breakfast eating patterns, to see if there was any change to body weight, nutrient intakes, and selected metabolic measures. The study lasted one year, and dietary recalls were collected throughout. The results showed that at the start of the trial 32.9% of the participants self-reported regularly skipped breakfast and generally they had lower levels of vitamins B1, B3 and folate intake. They also had a higher fat intake compared to those who ate breakfast. However, at the end of the year there was no statistical differences between those who ate and those who skipped breakfast when it came to the other metabolic parameters of weight, BMI, weight circumference, blood pressure, cholesterol, and fasting glucose. Interestingly at the end of the trial only 14% reported skipping breakfast suggesting that participants had the intention to change their eating patterns because of having participated in the trial. The study concluded that skipping breakfast alone was not enough to influence MetS.
Abstract
The effect of skipping breakfast on health, especially in adults, remains a controversial topic. A secondary data analysis was conducted to examine associations between breakfast eating patterns and weight loss, nutrient intake, and metabolic parameters among participants with metabolic syndrome (MetS) (n = 240). Three randomly selected 24-h dietary recalls were collected from each participant at baseline and at the one-year visit. Skipped breakfast was seen in 32.9% at baseline and in 17.4% at the one-year visit, respectively. At baseline, after adjustment for demographics and physical activity, participants who ate breakfast had a higher thiamin, niacin, and folate intake than did breakfast skippers (p < 0.05); other selected parameters including body weight, dietary quality scores, nutrient intake, and metabolic parameters showed no significant differences between the two groups (p ≥ 0.05). From baseline to one year, after adjustment for covariates, mean fat intake increased by 2.7% (95% confidence intervals (CI): -1.0, 6.5%) of total energy in breakfast skippers in comparison to the 1.2% decrease observed in breakfast eaters (95% CI: -3.4, 1.1%) (p = 0.02). Mean changes in other selected parameters showed no significant differences between breakfast skippers and eaters (p > 0.05). This study did not support the hypothesis that skipping breakfast has impact on body weight, nutrient intakes, and selected metabolic measures in participants with MetS.
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Vitamin D receptor gene FokI but not TaqI, ApaI, BsmI polymorphism is associated with Hashimoto's thyroiditis: a meta-analysis.
Wang, X, Cheng, W, Ma, Y, Zhu, J
Scientific reports. 2017;7:41540
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Vitamin D is a vitamin that is involved in several immune processes within the body. It acts on immune cells through binding to vitamin D receptors (VDR) and modulating their activity. However genetic variations in VDRs is apparent amongst individuals, with the four most common being TaqI, ApaI, FokI and BsmI. The presence of any of these variations has been associated with the development of several different diseases. This systematic review and meta-analysis aimed to determine whether any of these variations in the VDR was associated with the development of Hashimoto’s thyroiditis (HT), a disease whereby the immune system does not recognise and attacks the body’s own tissues. The results showed that only the FokI variation was associated with the development of HT and only in individuals with Asian heritage. It was concluded that the FokI variation of the VDR is associated with an increased risk of HT in Asians but not Caucasians, however how this occurs is not fully understood. This study could be used by healthcare professionals to understand that genetic variations on the VDR may be indicative of risk of developing HT in individuals from Asian descent.
Abstract
Four VD receptor (VDR) gene polymorphisms (TaqI, ApaI, FokI and BsmI) have been reported to influence Hashimoto's thyroiditis (HT) risk. However, individual studies have produced inconsistent results. We conducted a comprehensive meta-analysis of eleven case-control studies to better understand roles of the four polymorphisms in HT development. The results showed only FokI polymorphism was significantly associated with the risk of HT (F vs f: OR = 1.44, 95% CI = 1.09-1.91, P = 0.010; FF vs Ff + ff: OR = 1.72, 95% CI = 1.09-2.70, P = 0.019). Subgroup analyses demonstrated the significant effect was only present in Asian population (F vs f: OR = 1.45, 95% CI = 1.07-1.95, P = 0.016; FF vs ff: OR = 1.64, 95% CI = 1.03-2.59, P = 0.036; FF + Ff vs ff: OR = 1.34, 95% CI = 1.00-1.80, P = 0.047; FF vs Ff + ff: OR = 1.64, 95% CI = 1.03-2.64, P = 0.039), but not in Caucasian. For TaqI, ApaI and BsmI polymorphisms, no significant association was found in any model comparison. Based on the current literature, it appears that only VDR FokI polymorphism is associated with HT risk in Asian population, but not in Caucasians; and the TaqI, ApaI and BsmI polymorphisms have not positive association neither in the overall population, nor when stratified by ethnicity. Further well-designed studies with larger sample sizes and different ethnic population are needed to clarify the present findings.
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Spexin peptide is expressed in human endocrine and epithelial tissues and reduced after glucose load in type 2 diabetes.
Gu, L, Ma, Y, Gu, M, Zhang, Y, Yan, S, Li, N, Wang, Y, Ding, X, Yin, J, Fan, N, et al
Peptides. 2015;71:232-9
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Little is known about the functions of the peptide spexin. Recent studies have shown a relationship between spexin and body weight regulation. It is thought that spexin might be related to glucose control and fat metabolism in type 2 diabetes mellitus (T2DM). The aim of this study was to examine the location of spexin in human tissue and measure spexin levels after a glucose load in T2DM patients. First, the researchers examined human tissue samples. Blood samples were then collected from 121 adults with T2DM and 105 healthy individuals. Additionally, an oral glucose tolerance test (OGTT) was performed on 12 healthy volunteers. In human tissue samples, the levels of spexin were highest in the adrenal gland, skin, stomach, small intestine, liver, thyroid, pancreatic islets, visceral fat, lung, colon, and kidney, and lowest in muscle and connective tissue. Blood levels of spexin were significantly lower in T2DM patients compared to healthy controls. Spexin levels were found to be inversely related to fasting blood glucose and lipids. During the OGTT, spexin levels were also inversely correlated with blood glucose levels. The authors concluded that spexin is highly expressed among endocrine and epithelial tissues. Changes in the blood levels of spexin could represent an adaptation to the rise of glucose and lipids associated with T2DM. However, the exact role of spexin in endocrine diseases is still to be discovered.
Abstract
Spexin mRNA and protein are widely expressed in rat tissues and associate with weight loss in rodents of diet-induced obesity. Its location in endocrine and epithelial cells has also been suggested. Spexin is a novel peptide that involves weight loss in rodents of diet-induced obesity. Therefore, we aimed to examine its expression in human tissues and test whether spexin could have a role in glucose and lipid metabolism in type 2 diabetes mellitus (T2DM). The expression of the spexin gene and immunoreactivity in the adrenal gland, skin, stomach, small intestine, liver, thyroid, pancreatic islets, visceral fat, lung, colon, and kidney was higher than that in the muscle and connective tissue. Immunoreactive serum spexin levels were reduced in T2DM patients and correlated with fasting blood glucose (FBG, r=-0.686, P<0.001), hemoglobin A1c (HbA1c, r=-0.632, P<0.001), triglyceride (TG, r=-0.236, P<0.001) and low density lipoprotein-cholesterol (LDL-C, r=-0.382, P<0.001). A negative correlation of blood glucose with spexin was observed during oral glucose tolerance test (OGTT). Spexin is intensely expressed in normal human endocrine and epithelial tissues, indicating that spexin may be involved in physiological functions of endocrine and in several other tissues. Circulating spexin levels are low in T2DM patients and negatively related to blood glucose and lipids suggesting that the peptide may play a role in glucose and lipid metabolism in T2DM.