Fecal bacterial community changes associated with isoflavone metabolites in postmenopausal women after soy bar consumption.

UNLABELLED: Soy isoflavones and their metabolism by intestinal microbiota have gained attention because of potential health benefits, such as the alleviation of estrogen/hormone-related conditions in postmenopausal women, associated with some of these compounds. However, overall changes in gut bacterial community structure and composition in response to addition of soy isoflavones to diets and their association with excreted isoflavone metabolites in postmenopausal women has not been studied. The aim of this study was to determine fecal bacterial community changes in 17 postmenopausal women after a week of diet supplementation with soy bars containing isoflavones, and to determine correlations between microbial community changes and excreted isoflavone metabolites. Using DGGE profiles of PCR amplified 16S rRNA genes (V3 region) to compare microbial communities in fecal samples collected one week before and one week during soy supplementation revealed significant differences (ANOSIM p<0.03) before and after soy supplementation in all subjects. However, between subjects comparisons showed high inter-individual variation that resulted in clustering of profiles by subjects. Urinary excretion of isoflavone (daidzein) metabolites indicated four subjects were equol producers and all subjects produced O-desmethylangolensin (ODMA). Comparison of relative proportions of 16S rRNA genes from 454 pyrosequencing of the last fecal samples of each treatment session revealed significant increases in average proportions of Bifidobacterium after soy consumption, and Bifidobacterium and Eubacterium were significantly greater in equol vs non-S-(-)equol producers. This is the first in vivo study using pyrosequencing to characterize significant differences in fecal community structure and composition in postmenopausal women after a week of soy diet-supplementation, and relate these changes to differences in soy isoflavones and isoflavone metabolites. TRIAL REGISTRATION: Clinicaltrials.gov NCT00244907.

Dietary fat content and fiber type modulate hind gut microbial community and metabolic markers in the pig.

Obesity leads to changes in the gut microbial community which contribute to the metabolic dysregulation in obesity. Dietary fat and fiber affect the caloric density of foods. The impact of dietary fat content and fiber type on the microbial community in the hind gut is unknown. Effect of dietary fat level and fiber type on hindgut microbiota and volatile fatty acid (VFA) profiles was investigated. Expression of metabolic marker genes in the gut, adipose tissue and liver was determined. A 2 × 2 experiment was conducted in pigs fed at two dietary fat levels (5% or 17.5% swine grease) and two fiber types (4% inulin, fermentable fructo-oligosaccharide or 4% solka floc, non-fermentable cellulose). High fat diets (HFD) resulted in a higher (P<0.05) total body weight gain, feed efficiency and back fat accumulation than the low fat diet. Feeding of inulin, but not solka floc, attenuated (P<0.05) the HFD-induced higher body weight gain and fat mass accumulation. Inulin feeding tended to lead to higher total VFA production in the cecum and resulted in a higher (P<0.05) expression of acyl coA oxidase (ACO), a marker of peroxisomal ß-oxidation. Inulin feeding also resulted in lower expression of sterol regulatory element binding protein 1c (SREBP-1c), a marker of lipid anabolism. Bacteria community structure characterized by DGGE analysis of PCR amplified 16S rRNA gene fragments showed that inulin feeding resulted in greater bacterial population richness than solka floc feeding. Cluster analysis of pairwise Dice similarity comparisons of the DGGE profiles showed grouping by fiber type but not the level of dietary fat. Canonical correspondence analysis (CCA) of PCR- DGGE profiles showed that inulin feeding negatively correlated with back fat thickness. This study suggests a strong interplay between dietary fat level and fiber type in determining susceptibility to obesity.

Galactooligosaccharides improve mineral absorption and bone properties in growing rats through gut fermentation.

Galactooligosaccharides (GOS), prebiotic nondigestible oligosaccharides derived from lactose, have the potential for improving mineral balance and bone properties. This study examined the dose-response effect of GOS supplementation on calcium and magnesium absorption, mineral retention, bone properties, and gut microbiota in growing rats. Seventy-five 4-week-old male Sprague-Dawley rats were randomized into one of five treatment groups (n = 15/group) and fed a diet containing 0, 2, 4, 6, or 8% GOS by weight for 8 weeks. Dietary GOS significantly decreased cecal pH and increased cecal wall weight and content weight in a dose-dependent manner (p < 0.0001). Fingerprint patterns of the 16S rRNA gene PCR-DGGE from fecal DNA indicated the variance of bacterial community structure, which was primarily explained by GOS treatments (p = 0.0001). Quantitative PCR of the samples revealed an increase in the relative proportion of bifidobacteria with GOS (p = 0.0001). Net calcium absorption was increased in a dose-response manner (p < 0.01) with GOS supplementation. Dietary GOS also increased (p < 0.02) net magnesium absorption, femur 45Ca uptake, calcium and magnesium retention, and femur and tibia breaking strength. Distal femur total and trabecular volumetric bone mineral density (vBMD) and area and proximal tibia vBMD increased (p < 0.02) with GOS supplementation. Trabecular-rich bones, that is, those that rapidly turn over, were most benefited. Regression modeling showed that GOS benefited calcium and magnesium utilization and vBMD through decreased cecal pH, increased cecal wall and content weight, and increased proportion of bifidobacteria.

Predictors of long-term major adverse cardiac events and clinical restenosis following elective percutaneous coronary stenting.

Limited data exist regarding the predictors of long-term clinical outcomes following elective percutaneous coronary intervention (PCI) in the current era of stenting. The authors investigated the predictors of major adverse cardiac events (MACE) and clinical restenosis in 740 consecutive patients who underwent successful elective PCI with bare metal stents (BMSs) or drug-eluting stents (DESs). At 30-month follow-up, compared with BMS recipients, DES recipients had a significantly lower rate of MACE, which was mainly driven by a decreased repeat target vessel PCI. The rate of 30-month clinical restenosis was significantly lower in DES recipients. The authors conclude that baseline clinical, angiographic, and procedural characteristics determine long-term MACE and clinical restenosis after elective PCI, with DES being the independent predictor for both.

Predictors of periprocedural creatine kinase-myocardial band elevation complicating elective percutaneous coronary intervention.

Limited data are available regarding the predictors of periprocedural creatine kinase-MB (CK-MB) isoenzyme increase after elective percutaneous coronary intervention (PCI) in the stenting era. We explored the predictors of periprocedural CK-MB increase in 882 consecutive patients with normal preprocedural CK-MB who underwent 919 angiographically successful elective PCIs with (n = 814) or without (n = 105) stenting. Patients were categorized into 3 groups based on their peak CK-MB levels after PCI: (1) normal CK-MB (n = 761), (2) minor CK-MB increase (CK-MB 1 to 3 times normal, n = 112), and (3) major CK-MB increase (CK-MB >3 times normal, n = 46). By logistic regression analysis, independent predictors for minor CK-MB increase included thrombus (odds ratio [OR] 5.09, p = 0.001), platelet IIb/IIIa antagonist use (OR 0.53, p <0.01), number of lesions treated (per additional lesion, OR 1.54, p <0.01), maximum balloon size (per millimeter increase, OR 1.57, p <0.05), American College of Cardiology/American Heart Association type C lesion (OR 1.68, p <0.05), sustained chest pain during procedure (OR 1.94, p <0.05), dissection (OR 2.05, p <0.05), and transient side branch occlusion (OR 4.54, p <0.05). Independent predictors for major CK-MB increase were chest pain at end of procedure (OR 9.66, p <0.001), type C lesion (OR 2.42, p <0.05), Canadian Cardiovascular Society angina class III to IV (OR 3.32, p <0.05), thrombus (OR 5.09, p = 0.001), and abrupt closure (OR 5.30, p <0.05). In conclusion, baseline clinical and angiographic characteristics and procedural complications were associated with minor and major CK-MB increases. Patients with chest pain at the end of the procedure were at the highest risk for major CK-MB increase.