The effects of positional distribution of triacylglycerol (TAG) fatty acids to TAG structures in chylomicrons and VLDL, and to postprandial lipemia, were studied in 10 healthy premenopausal women ...using a 6-h oral fat load test and a randomized, double-blind cross-over design. Molecular level information of TAG regioisomerism was obtained with a tandem mass spectrometric method. The positional distribution of fatty acids in chylomicron TAGs was similar to the respective dietary fat; 79% of the analyzed regioisomers in palm oil and 84% of the analyzed regioisomers in transesterified oil were found in chylomicron TAGs 3 h after the oral fat loads. VLDL TAGs were equal after the two fat loads in all but one regioisomer. Similarities in the fatty acid compositions of chylomicron TAGs suggest that palmitic acid was absorbed equally from both test fats. The proportion of palmitoleic acid in the chylomicrons was increased. Fat with palmitic acid predominantly in the sn-1 and sn-3 positions caused a larger incremental area of total TAGs in plasma and reduced plasma insulin values at the beginning of the postprandial response (0-90 min) compared with fat with palmitic acid randomly distributed. The relationship between TAG molecular structures in dietary fats and in lipoproteins provides new means for understanding the effects of fatty acid positional distribution on human lipid metabolism.
ABSTRACT
In this study, the modulation of aflatoxin B
1
(AFB
1
) uptake in rats by administration of the probiotic
Lactobacillus rhamnosus
GG was demonstrated. Fecal AFB
1
excretion in GG-treated ...rats was increased via bacterial AFB
1
binding. Furthermore, AFB
1
-associated growth faltering and liver injury were alleviated with GG treatment.
Rye is an important source of plant lignans in Finland. In the present crossover trial we wanted to study the effect of rye bread as part of the usual diet on serum and urine enterolactone (ENL) ...concentrations in healthy volunteers. Eighteen men aged 43 (SEM 2·0) YEARS AND TWENTY-ONE WOMEN AGED 43 (sem 1·6) years consumed wholemeal rye bread and white wheat bread in random order for 4 weeks. The bread periods were separated by a 4 week wash-out period. The breads provided at least 20 % of the daily energy intake. The mean intakes of rye bread were 219 (sem 14·6) and 162 (sem 5·3) g/d and those of wheat bread were 200 (sem 9·6) and 153 (sem 5·8) g/d for men and women respectively. Blood samples were collected from all subjects and three 24 h urine samples were collected from ten men and twelve women at the end of both bread periods for the determination of serum concentration and urinary excretion of ENL. The mean serum ENL concentrations in both men and women at the beginning of baseline period and at the end of the rye-bread period remained constant and were significantly higher than those at the end of the wheat-bread period. Correspondingly, daily urinary ENL excretion increased significantly during the rye-bread period compared with the wheat-bread period and was 5- and 10-fold higher in men and women respectively in comparison with the amount of plant lignan precursors measured in the rye bread. These data indicate the presence of other precursors for ENL in rye which are not detected by the current method of measuring plant lignans in food. The possible role of fibre in enhancement of the formation of mammalian lignans from their plant precursors in the gut also remains to be determined.
Allium vegetables (onions, leeks, chives) and in particular garlic have been claimed to have health-promoting potential. This study was conducted to get insight into the perspectives for monitoring ...the intake of garlic by a biomarker approach. Chemically, the biomarker results from exposure to gamma-glutamyl-S-allyl-l-cysteine, which is first hydrolysed by gamma-glutamine-transpeptidase resulting in the formation of S-allyl-l-cysteine. The latter compound is subsequently N-acetylated by N-acetyltransferase into S-allyl-mercapturic acid (ALMA) and excreted into urine. The mercapturic acid was measured in urine using gaschromatography with mass spectrometry. Thus the intake of garlic was determined to check the compliance of garlic intake in a placebo-controlled intervention study. Results indicate that S-allyl-mercapturic acid could be detected in 15 out of 16 urine samples of garlic supplement takers, indicating good compliance. In addition, the intake of garlic was also monitored in a cross-section study of vegans versus controls in Finland, in which no differences in garlic consumption nor in ALMA output were recorded between vegans and controls. These data indicate good possibilities for further studies in the field of biomarkers to investigate the putative chemopreventive effects of garlic and garlic-containing products.
Aflatoxins are potent toxins and carcinogens which can be excreted in the milk of exposed lactating mothers mainly in the form of aflatoxin M(1) (AFM(1)). We previously evaluated the level and ...frequency of AFM(1) in breast milk in a group of Egyptian mothers attending the New El-Qalyub Hospital, Qalyubiyah governorate, Egypt. In this study, fifty of those women who were AFM(1) positive were revisited monthly for 12 months to assess the temporal variation in breast milk AFM(1). AFM(1) was detected in 248 of 443 (56%) samples. In a multilevel model of the data there was a highly significant (p<0.001) effect of month of sampling on the frequency of AFM(1) detection with summer months having the highest frequency (>80%) and winter months the lowest frequency (<20%) of detection. AFM(1) was observed most frequently in June OR 63, 95% CI (7.6, 522). The level of AFM(1) detection also followed this seasonal pattern with highest mean level in July (64 pg/ml milk, range 6.3-497 pg/ml milk) and the lowest mean level in January (8 pg/ml milk, range 4.2-108 pg/ml milk). The duration of lactation p=0.0035, OR=1.08, 95% CI (1.02, 1.13), and peanut consumption p=0.06, OR=1.69, 95% CI (0.9, 2.9) also contributed to the model. The identification and understanding of factors determining the presence of toxicants in human milk is important and may provide a knowledge driven basis for controlling the transfer of chemicals to infants.
Background: The present study was conducted to determine the effects of age and diet (breast milk, milk formula, weaning diet) on the activities of some bacterial enzymes in fecal samples collected ...from 3- to 24-month-old infants. These bacterial enzymes may generate toxic, mutagenic, or carcinogenic metabolites from plant glycosides (beta-glucuronidase, beta-glucosidase) or from urea (urease) Methods: The subjects were 68 healthy children ages 3 (n = 20), 6 (n = 20), 12 (n = 17), and 24 (n = 11) months. None of the children had been given any antibiotics during 4 weeks before collection of the fecal samples. Health status, bowel habits, and food consumption of the children were determined by interview of one of the parents using a structured questionnaire. A spot fecal sample from each child was collected. Results: The activities of beta-glucuronidase and beta-glucosidase increased from 0.52 and 1.17 nmol/min x mg protein (at 3 months) to 1.41 and 2.38 nmol/min x mg protein (at 2 years). respectively. However, at 2 years of age, the children had not yet reached the levels reported in earlier studies on adult populations. Urease activity increased from 4.18 nmol/min x mg protein (at 3 months) to 19.0 nmol/min x mg protein (at 2 years), reaching by 12 months of age the level observed in adults. Breast feeding as such had no consistent effect on fecal bacterial enzyme activities. beta-Glucuronidase and beta-glucosidase were higher in those 6- and 12-month-old children who consumed more meat, fish, sausages, or eggs. Conclusions: It can be concluded that the fecal enzyme activities in the gastrointestinal tract increase and that their profile changes with age and adoption of adult-type diet. It remains open, however, whether these changes are caused by the normal physiological aging process or by stepwise introduction of new foods to the diet.
Daily and inter-individual variations of faecal bacterial beta-glucuronidase and beta-glucosidase activities and their associations with parameters of bowel function were studied in 10 residents of ...an old people's home during two 1-week periods 2 weeks apart. The effect of sampling method (a spot sample vs an aliquot of the homogenized sample from a total daily collection) on the activities of these enzymes and that of urease was also assessed. Intestinal transit time was determined using the radio-opaque Sitzmark; capsules, and questionnaires on bowel function and intakes of fluids and fibre-containing foods were completed. The mean (95% confidence interval) beta-glucuronidase and beta-glucosidase levels were 3.08 (2.75-3.41) and 11.53 (10.79-12.26) nmol min-1 mg protein-1 . Daily X variations in enzyme activities within individuals were not significant (P = 0.277 and 0.990, respectively), whilst those between individuals were highly significant (P = 0.000). Faecal frequency correlated negatively with beta-glucuronidase and urease, but no other associations of the enzymic activities with parameters of bowel function and diet were observed. beta-Glucuronidase and beta-glucosidase were not affected by the sampling method, while significantly higher urease was obtained by spot sampling as compared with the aliquot representing the total daily collection. Large inter-individual variations in faecal enzyme activities should be taken into consideration when planning experiments and interpreting results on these faecal parameters.
In a genome‐wide association study of atorvastatin pharmacokinetics in 158 healthy volunteers, the SLCO1B1 c.521T>C (rs4149056) variant associated with increased area under the plasma ...concentration‐time curve from time zero to infinity (AUC0–∞) of atorvastatin (P = 1.2 × 10−10), 2‐hydroxy atorvastatin (P = 4.0 × 10−8), and 4‐hydroxy atorvastatin (P = 2.9 × 10−8). An intronic LPP variant, rs1975991, associated with reduced atorvastatin lactone AUC0–∞ (P = 3.8 × 10−8). Three UGT1A variants linked with UGT1A3*2 associated with increased 2‐hydroxy atorvastatin lactone AUC0–∞ (P = 3.9 × 10−8). Furthermore, a candidate gene analysis including 243 participants suggested that increased function SLCO1B1 variants and decreased activity CYP3A4 variants affect atorvastatin pharmacokinetics. Compared with individuals with normal function SLCO1B1 genotype, atorvastatin AUC0–∞ was 145% (90% confidence interval: 98‐203%; P = 5.6 × 10−11) larger in individuals with poor function, 24% (9‐41%; P = 0.0053) larger in those with decreased function, and 41% (16‐59%; P = 0.016) smaller in those with highly increased function SLCO1B1 genotype. Individuals with intermediate metabolizer CYP3A4 genotype (CYP3A4*2 or CYP3A4*22 heterozygotes) had 33% (14‐55%; P = 0.022) larger atorvastatin AUC0–∞ than those with normal metabolizer genotype. UGT1A3*2 heterozygotes had 16% (5‐25%; P = 0.017) smaller and LPP rs1975991 homozygotes had 34% (22‐44%; P = 4.8 × 10−5) smaller atorvastatin AUC0‐∞ than noncarriers. These data demonstrate that genetic variation in SLCO1B1, UGT1A3, LPP, and CYP3A4 affects atorvastatin pharmacokinetics. This is the first study to suggest that LPP rs1975991 may reduce atorvastatin exposure. Correction added on 6 April, after first online publication: An incomplete sentence (“= 0.017) smaller in heterozygotes for UGT1A3*2 and 34% (22%, 44%; P × 10−5) smaller in homozygotes for LPP noncarriers.”) has been corrected in this version.
The effects of yogurt containing viable Lactobacillus strain GG (L. GG) and/or fiber supplements on fecal enzyme activities (beta-glucuronidase, nitroreductase, beta-glucosidase, glycocholic acid ...hydrolase, urease) and on bacterial metabolites in urine (phenol, p-cresol) were studied in 64 females, 20-41 y old. The subjects were randomly divided into three groups: the first group received L. GG yogurt (2 X 150 ml/d, containing 10(11) colony-forming units (cfu)/L of L. GG), the second group received L. GG yogurt and a rye fiber product (30 g/d, equivalent to 9 g fiber/d), and the third group received placebo yogurt (pasteurized) and fiber. The supplementation period lasted 4 wk, with a preceding ?-wk baseline period and a 2-wk follow-up period. The mean fecal count of L. GG was approximately 10(6) cfu/g feces during the supplementation, and L. GG persisted in the fecal samples of 28% of the subjects for 2 wk after supplementation. L. GG yogurt alone or with fiber significantly decreased fecal beta-glucuronidase, nitroreductase and glycocholic acid hydrolase activities. These enzyme activities returned to baseline levels during the follow-up period. beta-Glucosidase and urease activities were not altered significantly during the study. The addition of fiber to L. GG and placebo yogurt had no effect on the enzymic activities. Urinary excretion of p-cresol decreased significantly in groups receiving L. GG. These data demonstrate that L. GG can modify the colonic environment with possible health effects.
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