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Serum, Urine, and Fecal Metabolome Alterations in the Gut Microbiota in Response to Lifestyle Interventions in Pediatric Obesity: A Non-Randomized Clinical Trial.
Lee, Y, Cho, JY, Cho, KY
Nutrients. 2023;15(9)
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Paediatric obesity is linked to an increased risk of type 2 diabetes, hypertension, dyslipidaemia, and metabolic syndrome. Diverse evidence suggests that obesity is associated with alterations in the gut microbiota and its metabolites. The aim of this study was to understand the metabolic pathways underlying paediatric obesity and the effect of intervention, which could provide guidance for the treatment of obesity. This study was a non-randomised clinical trial which enrolled 50 children with obesity and 22 normal-weight children aged 7–18 years. Results showed that imbalances in microbiota and metabolites were associated with both obesity and response to the intervention. The most distinct metabolic alterations in the obese group were branched-chain amino acid and purine changes. Authors conclude that the findings of their study could be valuable for identifying novel targets and biomarkers for the treatment of obesity.
Abstract
Pediatric obesity is associated with alterations in the gut microbiota and its metabolites. However, how they influence obesity and the effect of lifestyle interventions remains unknown.. In this non-randomized clinical trial, we analyzed metabolomes and microbial features to understand the associated metabolic pathways and the effect of lifestyle interventions on pediatric obesity. Anthropometric/biochemical data and fasting serum, urine, and fecal samples were collected at baseline and after an eight-week, weight-reduction lifestyle modification program. Post-intervention, children with obesity were classified into responder and non-responder groups based on changes in total body fat. At baseline, serum L-isoleucine and uric acid levels were significantly higher in children with obesity compared with those in normal-weight children and were positively correlated with obesogenic genera. Taurodeoxycholic and tauromuricholic α + β acid levels decreased significantly with obesity and were negatively correlated with obesogenic genera. Branched-chain amino acid and purine metabolisms were distinguished metabolic pathways in the obese group. Post-intervention, urinary myristic acid levels decreased significantly in the responder group, showing a significant positive correlation with Bacteroides. Fatty acid biosynthesis decreased significantly in the responder group. Thus, lifestyle intervention with weight loss is associated with changes in fatty acid biosynthesis, and myristic acid is a possible therapeutic target for pediatric obesity.
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Impact of dietary interventions on pre-diabetic oral and gut microbiome, metabolites and cytokines.
Shoer, S, Shilo, S, Godneva, A, Ben-Yacov, O, Rein, M, Wolf, BC, Lotan-Pompan, M, Bar, N, Weiss, EI, Houri-Haddad, Y, et al
Nature communications. 2023;14(1):5384
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Pre-diabetes, a condition characterized by elevated blood glucose levels but below diabetes thresholds, is a significant risk factor for the development of type 2 diabetes, as well as other comorbidities including cardiovascular and kidney diseases. Diet plays a critical role in the development of hyperglycaemia and the onset of pre-diabetes. The aim of this study was to assess the impact of a personalized postprandial glucose-targeting diet (PPT), as well as the standard of care Mediterranean diet (MED), on the oral and gut microbiome, metabolites and cytokines in 200 pre-diabetic individuals. This study was a biphasic, randomised, controlled, single-blind dietary intervention. Phase one included a six-month intervention that compared two diets targeting glycaemic control, while phase two included a six-month follow-up period. Participants (n = 225) were randomly assigned in a 1:1 ratio to a PPT (n = 113) or a MED (n = 112). Results showed that participants assigned to the PPT diet had significant changes in 19 gut microbial species, 14 gut and one oral microbial pathway, 86 serum metabolites and four cytokines. Participants assigned to the MED diet showed significant changes in five gut and one oral microbial species, 18 gut microbial pathways, 27 serum metabolites and four cytokines. Authors conclude that dietary interventions can affect the microbiome, cardiometabolic profile and immune response of the host. Thus, diets such as the PPT used in this study, which takes into account microbiome features, could be designed to affect the microbiome and inflict desired metabolic outcomes.
Abstract
Diabetes and associated comorbidities are a global health threat on the rise. We conducted a six-month dietary intervention in pre-diabetic individuals (NCT03222791), to mitigate the hyperglycemia and enhance metabolic health. The current work explores early diabetes markers in the 200 individuals who completed the trial. We find 166 of 2,803 measured features, including oral and gut microbial species and pathways, serum metabolites and cytokines, show significant change in response to a personalized postprandial glucose-targeting diet or the standard of care Mediterranean diet. These changes include established markers of hyperglycemia as well as novel features that can now be investigated as potential therapeutic targets. Our results indicate the microbiome mediates the effect of diet on glycemic, metabolic and immune measurements, with gut microbiome compositional change explaining 12.25% of serum metabolites variance. Although the gut microbiome displays greater compositional changes compared to the oral microbiome, the oral microbiome demonstrates more changes at the genetic level, with trends dependent on environmental richness and species prevalence in the population. In conclusion, our study shows dietary interventions can affect the microbiome, cardiometabolic profile and immune response of the host, and that these factors are well associated with each other, and can be harnessed for new therapeutic modalities.
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Gut microbiota in nonalcoholic fatty liver disease: a PREDIMED-Plus trial sub analysis.
Gómez-Pérez, AM, Ruiz-Limón, P, Salas-Salvadó, J, Vioque, J, Corella, D, Fitó, M, Vidal, J, Atzeni, A, Torres-Collado, L, Álvarez-Sala, A, et al
Gut microbes. 2023;15(1):2223339
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Nonalcoholic fatty liver disease (NAFLD) is the main cause of chronic liver disease. The aim of this study was to evaluate the changes in the microbiota associated with changes in biochemical markers of NAFLD/NASH after an intervention. This substudy was conducted in the frame of the PREDIMED-Plus study, a 6-year, multicentre, randomised clinical trial for primary prevention of cardiovascular disease (CVD) conducted in men aged 55–75 years and women aged 60–75 years with overweight or obesity and metabolic syndrome. Results showed a relationship between liver disease biochemical indexes changes and gut microbiota changes within a context of a Mediterranean lifestyle. In fact, two noninvasive scores for liver steatosis and liver fibrosis, usually used in clinical practice, could differentiate gut microbiota populations. Authors conclude that their findings highlight the importance of lifestyle intervention in the modulation of gut microbiota and the management of metabolic syndrome and its hepatic manifestations.
Abstract
To evaluate the changes in the gut microbiota associated with changes in the biochemical markers of nonalcoholic fatty liver disease (NAFLD) after a lifestyle intervention with the Mediterranean diet. Participants (n = 297) from two centers of PREDIMED-Plus trial (Prevención con Dieta Mediterránea) were divided into three different groups based on the change tertile in the Hepatic Steatosis Index (HSI) or the Fibrosis-4 score (FIB-4) between baseline and one year of intervention. One-year changes in HSI were: tertile 1 (T1) (-24.9 to -7.51), T2 (-7.5 to -1.86), T3 (-1.85 to 13.64). The most significant differences in gut microbiota within the year of intervention were observed in the T1 and T3. According to the FIB-4, participants were categorized in non-suspected fibrosis (NSF) and with indeterminate or suspected fibrosis (SF). NSF participants showed higher abundances of Alcaligenaceae, Bacteroidaceae, Bifidobacteriaceae, Clostridiaceae, Enterobacteriaceae, Peptostreptococcaceae, Verrucomicrobiaceae compared to those with SF. Then, participants were divided depending on the FIB-4 tertile of change: T1 (-89.60 to -5.57), T2 (-5.56 to 11.4), and T3 (11.41 to 206.24). FIB-4 T1 showed a decrease in Akkermansia and an increase in Desulfovibrio. T2 had an increase in Victivallaceae, Clostridiaceae, and Desulfovibrio. T3 showed a decrease in Enterobacteriaceae, and an increase in Sutterella, Faecalibacterium, and Blautia. A relation between biochemical index changes of NAFLD/NASH (HSI and FIB-4) and gut microbiota changes were found. These observations highlight the importance of lifestyle intervention in the modulation of gut microbiota and the management of metabolic syndrome and its hepatic manifestations. What You Need to KnowWhat is the context:Obesity and metabolic syndrome have been associated with nonalcoholic fatty liver disease (NAFLD). Gut microbiota and its interaction with the environment may play a key role in NAFLD.What is new:Mediterranean diet and physical activity can modify the scores for liver steatosis (HSI) and liver fibrosis (FIB−4) in only one year. A relation between the changes in these scores and gut microbiota changes was found.What is the impact:The discovery of microbiota-based biomarkers for NAFLD and the development of strategies to modulate gut microbiota in the treatment of NAFLD.
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An insight into the functional alterations in the gut microbiome of healthy adults in response to a multi-strain probiotic intake: a single arm open label trial.
Rodenes-Gavidia, A, Lamelas, A, Bloor, S, Hobson, A, Treadway, S, Haworth, J, Vijayakumar, V, Naghibi, M, Day, R, Chenoll, E
Frontiers in cellular and infection microbiology. 2023;13:1240267
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The human gut microbiota is a key mediator of host health and is known to affect many physiological processes, such as digestion, metabolism, immune function and inhibition of pathogen colonisation. The gut microbiome can be impacted by many extrinsic factors. The aim of this study was to assess both compositional and functional changes in the microbiome of healthy individuals using shotgun metagenomics following 8-weeks of daily multi-strain probiotic intake. This study was a single-arm open-label study which enrolled a total of 41 healthy adult males and females between 18 to 40 years old. Results showed that alpha- and beta-diversity of the faecal microbiota structure was not significantly altered in response to probiotic intake. However, significant changes were observed when functional genes were assessed. Abundance of certain genes involved in several functional pathways were also significantly altered. Additionally, there were no significant changes in stool frequency or consistency, faecal biochemistry, or breath tests of methane and hydrogen observed. Authors conclude that the findings of their study have the potential to provide insights into the underlying mechanisms of action of the 14-strain probiotic blend in healthy adults.
Abstract
BACKGROUND Probiotic supplements, by definition, provide a benefit to the host, but few studies have investigated the effect of probiotic supplements in healthy adult populations. PURPOSE The present, single arm, open label clinical trial, evaluated compositional and functional changes in the fecal microbiome of healthy adults after supplementation with a 14-strain probiotic. METHODS We analysed the effect of a 14-strain probiotic blend (Bacillus subtilis NCIMB 30223, Bifidobacterium bifidum NCIMB 30179, B. breve NCIMB 30180, B. infantis NCIMB 30181, B. longum NCIMB 30182, Lactobacillus helveticus NCIMB 30184, L. delbrueckii subsp. bulgaricus NCIMB 30186, Lacticaseibacillus paracasei NCIMB 30185, Lactiplantibacillus plantarum NCIMB 30187, Lacticaseibacillus rhamnosus NCIMB 30188, L. helveticus NCIMB 30224, Lactobacillus salivarius NCIMB 30225, Lactococcus lactis subsp. lactis NCIMB 30222, and Streptococcus thermophilus NCIMB 30189), on the faecal microbiota of healthy young adults (n=41) in a single arm study. The adults consumed 4 capsules daily of the 14 strain blend(8 billion colony forming units/day) for 8 weeks. Compositional and functional changes in faecal microbiota before and after supplementation were assessed using shotgun metagenomic sequencing. Fasting breath analysis, faecal biochemistry and bowel habits were also assessed. RESULTS In healthy adult participants, no significant changes to the overall alpha- or beta-diversity was observed after 8 weeks of multi-strain probiotic supplementation. However, in a simplified model that considered only time and individual differences, significant decreases (p < 0.05) in family Odoribacteraceae and Bacteroidaceae abundance and a significant increase (p < 0.05) in genus Megamonas abundance were observed. At a functional level, there were significant changes in functional gene abundance related to several functional pathways, including phenylalanine metabolism, O-antigen nucleotide sugar biosynthesis, bacterial chemotaxis, and flagellar assembly. No significant changes in stool form or frequency, fecal biochemistry, or methane and hydrogen breath tests were observed. CONCLUSION In healthy young adults, overall alpha- and beta-diversity did not change in response to probiotic intake even though modest compositional changes at the family and genus level were observed. However, at functional level, results identified changes in gene abundance for several functional pathways.
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Human milk miRNAs associate to maternal dietary nutrients, milk microbiota, infant gut microbiota and growth.
Yeruva, L, Mulakala, BK, Rajasundaram, D, Gonzalez, S, Cabrera-Rubio, R, Martínez-Costa, C, Collado, MC
Clinical nutrition (Edinburgh, Scotland). 2023;42(12):2528-2539
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Human milk is a source of nutrition during the early stages of development. Human milk contains nutritive and non-nutritive bioactives such as microRNAs (miRNAs or miRs). These bioactives likely program an infant's growth, development, and physiological systems (i.e., immune system, brain, liver). The aim of this study was to examine the potential impact of maternal diet on human milk miRNAs profile and the link to microbiota. This study was an observational study which included a subset of 60 healthy lactating women (n = 30 milk samples in each cluster). Results showed that that: - human milk miRNA's profile was altered based on maternal dietary protein source (plant or animal protein). - miRNA features were distinct based on maternal diet intake and correlated with dietary plant polyphenols, and milk microbiota. - milk miRNAs, irrespective of maternal dietary source, have a strong correlation with infant gut microbiota early in life as well as to infant anthropometric measures. Authors concluded that their findings extend current knowledge that milk miRNAs are differentially expressed based on maternal protein source, associate with specific set of milk microbiota and maternal intake of polyphenols, and infant microbiota for optimal growth and development.
Abstract
BACKGROUND Maternal diet influences the milk composition, yet little information is available on the impact of maternal diet on milk miRNAs expression. Further, the association of human milk miRNAs to maternal diet and milk microbiota is not explored. In addition, the role of milk miRNAs on the infant gut microbiota, infant growth and development has not been investigated. METHODS Milk samples were collected from 60 healthy lactating women at ≤15d post-partum, HTG transcriptome assay was performed to examine milk miRNA profile. Maternal clinical and dietary clusters information were available and infant anthropometric measures were followed up to one year of age. Milk and infant microbiota were analyzed by 16S rRNA gene sequencing and integrative multi-omics data analysis was performed to identify potential association between microRNA, maternal dietary nutrients and microbiota. RESULTS Discriminant analysis revealed that the milk miRNAs were clustered into groups according to the maternal protein source. Interestingly, 31 miRNAs were differentially expressed (P adj < 0.05) between maternal dietary clusters (Cluster 1: enriched in plant protein and fibers and Cluster 2: enriched in animal protein), with 30 miRNAs downregulated in the plant protein group relative to animal protein group. Pathway analysis revealed that the top enriched pathways (P adj < 0.01) were involved in cell growth and proliferation processes. Furthermore, significant features contributing to the clustering were associated with maternal dietary nutrients and milk microbiota (r > 0.70). Further, miR-378 and 320 family miRNAs involved in adipogenesis were positively correlated to the infant BMI-z-scores, weight, and weight for length-z-scores at 6 months of age. CONCLUSIONS Maternal dietary source impacts the milk miRNA expression profile. Further, miRNAs were associated with maternal dietary nutrients, milk microbiota and to the infant gut microbiota and infant growth and development. CLINICAL TRIAL The study is registered in ClinicalTrials.gov. The identification number is NCT03552939.
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Time-restricted feeding's effect on overweight and obese patients with chronic kidney disease stages 3-4: A prospective non-randomized control pilot study.
Lao, BN, Luo, JH, Xu, XY, Fu, LZ, Tang, F, Ouyang, WW, Xu, XZ, Wei, MT, Xiao, BJ, Chen, LY, et al
Frontiers in endocrinology. 2023;14:1096093
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Obesity is a chronic metabolic disease caused by multiple factors. It is an independent risk factor for the development and progression of chronic kidney disease (CKD). The aim of this study was to explore the efficacy and safety of TRF in overweight and obese patients with moderate-to-severe stage CKD. This study was a prospective, non-randomised, controlled exploratory intervention study. Twenty-eight participants were included in the study, and were assigned to either the time-restricted feeding (TRF) group or the control diet (CD) group according to their preferences. Results showed that: - TRF helped improve renal function in overweight and obese moderate-to-severe CKD patients. - the TRF group experienced some hunger, but within tolerable range, and stated that TRF adherence was good. - the TRF group experienced a decrease in serum phosphate and uric acid, maintenance of total protein and albumin. - TRF shifted the gut microbiota in a positive direction. Authors concluded that TRF may be a safe and effective dietary intervention for overweight and obese CKD patients.
Abstract
BACKGROUND Time-restricted feeding (TRF) has become a popular weight loss method in recent years. It is widely used in the nutritional treatment of normal obese people and obese people with chronic diseases such as diabetes mellitus and hypertension, and has shown many benefits. However, most TRF studies have excluded chronic kidney disease (CKD) patients, resulting in a lack of sufficient evidence-based practice for the efficacy and safety of TRF therapy for CKD. Therefore, we explore the efficacy and safety of TRF in overweight and obese patients with moderate-to-severe stage CKD through this pilot study, and observe patient compliance to assess the feasibility of the therapy. METHODS This is a prospective, non-randomized controlled short-term clinical trial. We recruited overweight and obese patients with CKD stages 3-4 from an outpatient clinic and assigned them to either a TRF group or a control diet (CD) group according to their preferences. Changes in renal function, other biochemical data, anthropometric parameters, gut microbiota, and adverse events were measured before the intervention and after 12 weeks. RESULTS The change in estimated glomerular filtration rate (eGFR) before and after intervention in the TRF group (Δ = 3.1 ± 5.3 ml/min/1.73m2) showed significant improvement compared with the CD group (Δ = -0.8 ± 4.4 ml/min/1.73m2). Furthermore, the TRF group had a significant decrease in uric acid (Δ = -70.8 ± 124.2 μmol/L), but an increase in total protein (Δ = 1.7 ± 2.5 g/L), while the changes were inconsistent for inflammatory factors. In addition, the TRF group showed a significant decrease in body weight (Δ = -2.8 ± 2.9 kg) compared to the CD group, and body composition indicated the same decrease in body fat mass, fat free mass and body water. Additionally, TRF shifted the gut microbiota in a positive direction. CONCLUSION Preliminary studies suggest that overweight and obese patients with moderate-to-severe CKD with weight loss needs, and who were under strict medical supervision by healthcare professionals, performed TRF with good compliance. They did so without apparent adverse events, and showed efficacy in protecting renal function. These results may be due to changes in body composition and alterations in gut microbiota.
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Dynamics of gut microbiota during pregnancy in women with TPOAb-positive subclinical hypothyroidism: a prospective cohort study.
Wu, M, Chi, C, Yang, Y, Guo, S, Li, T, Gu, M, Zhang, T, Gao, H, Liu, R, Yin, C
BMC pregnancy and childbirth. 2022;22(1):592
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Subclinical hypothyroidism (SCH) in pregnancy refers to the elevation of thyroid stimulating hormone level with normal free T4 level. One third of women with SCH have been reported to test positive for anti-thyroid peroxidase antibody (TPOAb+). The aim of this study was to evaluate whether gut microbiota can be potential therapeutic targets for managing TPOAb+ SCH. This study was a nested, prospective observational cohort study. A total of 64 and 68 pregnant women with TPOAb+ and TPOAb negative SCH, respectively, were included in this study. Results showed that women who were diagnosed with TPOAb+ SCH in trimester (T)1 show distinct dynamics of gut microbiota from T2 to T3. Furthermore, changes in the abundances of three types of bacterial species were abnormal in the presence of levothyroxine treatment. Authors conclude that gut microbiota can serve as potential therapeutic targets for TPOAb+ SCH during pregnancy.
Abstract
BACKGROUND Anti-thyroid peroxidase antibody (TPOAb) positivity can contribute to inhibit thyroxine synthesis. Gut microbiota can interact with metabolic or immune diseases. However, dynamics of gut microbiota from the second (T2) to the third trimester (T3) in women with TPOAb-positive/negative subclinical hypothyroidism (TPOAb+/TPOAb- SCH) have not been reported. Therefore, we aimed to evaluate whether gut microbiota can be potential therapeutic targets for managing TPOAb+ SCH. METHODS In this single-center prospective cohort study, we observed gut microbiota dynamics by sequencing 16S rRNA from fecal samples collected in T2 (20-23+ 6 weeks) and T3 (28-33+ 6 weeks). TPOAb+/TPOAb- SCH were stratified depending on whether or not they used levothyroxine (LT4) during the pregnancy (LT4+/LT4-). Microbiome bioinformatics analyses were performed using QIIME2. The linear discriminant analysis effect size (LEfSe) was used for the quantitative analysis of biomarkers. Functional profiling was performed with PICRUSt2. RESULTS Distinct gut microbiota dynamics from T2 to T3 were noted in the TPOAb- (n = 68) and TPOAb+ (n = 64) SCH groups. The TPOAb+ LT4- group was characterized by enriched bacterial amplicon sequence variants (ASVs) of Prevotella in T2 and Bacteria, Lachnospirales, Lachnospiraceae, Blautia, and Agathobacter in T3 and by depleted ASVs of Gammaproteobacteria, Enterobacterales, and Enterobacteriaceae in T2 and Actinobacteriota, Coriobacteriia, Actinobacteria, Coriobacteriales, Bifidobacteriales, Bifidobacteriaceae, Bifidobacterium, Dorea formicigenerans, and Bifidobacterium longum in T3. The TPOAb+ LT4+ group was characterized by enriched bacterial ASVs of Blautia, Streptococcus salivarius, and Bifidobacterium longum in T3 and by depleted ASVs of Bacteroidota, Bacteroidia, Bacteroidales, and Prevotella in T2 and Agathobacter in T3. Moreover, we identified 53 kinds of metabolic functions that were mainly involved in sugar, lipid, and amino acid metabolism. CONCLUSIONS Our results indicated that low dynamics of gut microbiota composition and high dynamics of its metabolic function from T2 to T3 were associated with TPOAb+ SCH. We concluded that gut microbiota could be new targets for treatment of TPOAb+ SCH during pregnancy. TRIAL REGISTRATION This study was retrospectively registered at the Chinese Clinical Trial Registry (registration number ChiCTR2100047175 ) on June 10, 2021.
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Gut microbiota varies by opioid use, circulating leptin and oxytocin in African American men with diabetes and high burden of chronic disease.
Barengolts, E, Green, SJ, Eisenberg, Y, Akbar, A, Reddivari, B, Layden, BT, Dugas, L, Chlipala, G
PloS one. 2018;13(3):e0194171
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Obesity and type 2 diabetes (T2D) can lead to alterations of the composition of the gut microbiota. The gut microbiota, in turn, has been suggested to play a role in the development of psychological conditions, such as anxiety, depression and drug addiction. This cross-sectional study included 99 mostly overweight/obese African American men, with or without T2D, and with or without opioid addiction and other psychiatric disorders. The aim of the study was to determine, whether the gut microbiota composition was linked to T2D and the use of opioids in these patients. Furthermore, the researchers looked at the associations between leptin and oxytocin levels in the blood and the gut microbiota, and whether these hormone biomarkers could be indicative of obesity and psychosocial behaviour, such as opioid addiction. The authors found that some bacterial species in the gut were affected by T2D, diabetes medication and opioid use in the studied subjects. A relationship was also observed between leptin and oxytocin levels and the abundance of certain bacteria in the gut in subjects without T2D. The authors conclude that targeting the gut microbiota could be used for the management of T2D and associated psychiatric disorders. However, more studies are needed to provide further understanding of the connections between the gut microbiota and the brain.
Abstract
OBJECTIVE The gut microbiota is known to be related to type 2 diabetes (T2D), psychiatric conditions, and opioid use. In this study, we tested the hypothesis that variability in gut microbiota in T2D is associated with psycho-metabolic health. METHODS A cross-sectional study was conducted among African American men (AAM) (n = 99) that were outpatients at a Chicago VA Medical Center. The main outcome measures included fecal microbiota ecology (by 16S rRNA gene sequencing), psychiatric disorders including opioid use, and circulating leptin and oxytocin as representative hormone biomarkers for obesity and psychological pro-social behavior. RESULTS The study subjects had prevalent overweight/obesity (78%), T2D (50%) and co-morbid psychiatric (65%) and opioid use (45%) disorders. In the analysis of microbiota, the data showed interactions of opioids, T2D and metformin with Bifidobacterium and Prevotella genera. The differential analysis of Bifidobacterium stratified by opioids, T2D and metformin, showed significant interactions among these factors indicating that the effect of one factor was changed by the other (FDR-adjusted p [q] < 0.01). In addition, the pair-wise comparison showed that participants with T2D not taking metformin had a significant 6.74 log2 fold increase in Bifidobacterium in opioid users as compared to non-users (q = 2.2 x 10-8). Since metformin was not included in this pair-wise comparison, the significant 'q' suggested association of opioid use with Bifidobacterium abundance. The differences in Bifidobacterium abundance could possibly be explained by opioids acting as organic cation transporter 1 (OCT1) inhibitors. Analysis stratified by lower and higher leptin and oxytocin (divided by the 50th percentile) in the subgroup without T2D showed lower Dialister in High-Leptin vs. Low-Leptin (p = 0.03). Contrary, the opposite was shown for oxytocin, higher Dialister in High-Oxytocin vs. Low-Oxytocin (p = 0.04). CONCLUSIONS The study demonstrated for the first time that Bifidobacterium and Prevotella abundance was affected by interactions of T2D, metformin and opioid use. Also, in subjects without T2D Dialister abundance varied according to circulating leptin and oxytocin.