European Journal of Nutrition (v.54, #8)
Advanced physiological roles of guanidinoacetic acid by Sergej M. Ostojic (1211-1215).
Dietary guanidinoacetic acid (GAA) seems to improve cellular bioenergetics by stimulating creatine biosynthesis. However, GAA could have other biological functions that might affect its possible use as a food ingredient in human nutrition. In this paper, we identified several alternative physiological roles of supplemental GAA, including the stimulation of hormonal release and neuromodulation, an alteration of metabolic utilization of arginine, and an adjustment of oxidant–antioxidant status. A better knowledge of how GAA affects human physiology may facilitate its use as an experimental nutritional intervention for novel purposes and conditions.
Keywords: Guanidinoacetic acid; Creatine; Insulin; Arginine; Pro-oxidant
Impact of basal diet on dextran sodium sulphate (DSS)-induced colitis in rats by Ahlem Boussenna; Nicolas Goncalves-Mendes; Juliette Joubert-Zakeyh; Bruno Pereira; Didier Fraisse; Marie-Paule Vasson; Odile Texier; Catherine Felgines (1217-1227).
Dextran sodium sulphate (DSS)-induced colitis is a widely used model for inflammatory bowel disease. However, various factors including nutrition may affect the development of this colitis. This study aimed to compare and characterize the impact of purified and non-purified basal diets on the development of DSS-induced colitis in the rat. Wistar rats were fed a non-purified or a semi-synthetic purified diet for 21 days. Colitis was then induced in half of the rats by administration of DSS in drinking water (4 % w/v) during the last 7 days of experimentation. At the end of the experimental period, colon sections were taken for histopathological examination, determination of various markers of inflammation (myeloperoxidase: MPO, cytokines) and oxidative stress (superoxide dismutase: SOD, catalase: CAT, glutathione peroxidase: GPx and glutathione reductase: GRed activities), and evaluation of the expression of various genes implicated in this disorder. DSS ingestion induced a more marked colitis in animals receiving the purified diet, as reflected by higher histological score and increased MPO activity. A significant decrease in SOD and CAT activities was also observed in rats fed the purified diet. Also, in these animals, administration of DSS induced a significant increase in interleukin (IL)-1α, IL-1β and IL-6. In addition, various genes implicated in inflammation were over-expressed after ingestion of DSS by rats fed the purified diet.These results show that a purified diet promotes the onset of a more severe induced colitis than a non-purified one, highlighting the influence of basal diet in colitis development.
Keywords: Purified diet; Dextran sodium sulphate; Colitis; Oxidative stress; Rat
A novel Mediterranean diet index from Lebanon: comparison with Europe by Farah Naja; Nahla Hwalla; Leila Itani; Shirine Baalbaki; Abla Sibai; Lara Nasreddine (1229-1243).
To propose an index for assessing adherence to a Middle Eastern version of the Mediterranean diet as represented by the Traditional Lebanese Mediterranean diet (LMD), to evaluate the association between the LMD and selected European Mediterranean diets (EMD), and to examine socio-demographic and lifestyle correlates of adherence to Mediterranean diet (MD) among Lebanese adults.Using nationally representative dietary intake data of Lebanese adults, an index to measure Adherence to the LMD was derived. The choice of foods/food groups used for calculating the LMD score was based on results of previous factor analyses conducted on the same dataset. These foods/food groups included fruits, vegetables, legumes, olive oil, burghol, dairy products, starchy vegetables, dried fruits and eggs. Using Pearson’s correlation and scores tertiles distributions agreement, the derived LMD index was compared to previously published EMD indexes from Greece, Spain, Italy, France and EPIC/Europe.Fruits, vegetables and olive oil were common denominators to most MD scores. Food groups, specific to the LMD, included burghol, dried fruits, and eggs. The LMD score significantly correlated with the EMD scores, while being closest to the Italian (r = 0.56) and farthest from the French (r = 0.21). Percent agreement between scores’ tertile distributions and Kappa statistics confirmed these findings. Multivariate linear regressions showed that older age and higher educational levels were associated with increased adherence to all MDs studied.A novel LMD index was proposed to assess adherence to a Middle Eastern version of MD, complementing international efforts to characterize the MD and its association with disease risk.
Keywords: Mediterranean diet; Adherence; Middle East; Lebanon; Europe
Angiotensin-converting enzyme gene insertion/deletion polymorphism in nutritional disorders in children by Cristina Oana Mărginean; Claudia Bănescu; Carmen Duicu; Septimiu Voidăzan; Claudiu Mărginean (1245-1254).
The aim of this study was to establish the role of angiotensin-converting enzyme gene insertion/deletion (ACE I/D) polymorphism in determining obesity or undernutrition in a child population in Romania. We assessed 293 consecutively hospitalized patients in a tertiary emergency pediatric hospital. The patients were divided, according to body mass index (BMI), into three groups: group I, the control group consisting of 126 children, group II patients with undernutrition (85 patients) and group III patients with obesity (82 patients). ACE I/D polymorphisms were performed in all three patient groups, as well as the measuring of anthropometric parameters [middle upper arm circumference (MUAC), tricipital skinfold thickness (TST)]. All patients also underwent paraclinical evaluations (protein and albumin). The cutoffs criteria for moderate undernutrition were: BMI between −2.0 SD and −3.0 SD, severe undernutrition: BMI <−3.0 SD, moderate obesity: BMI between +2.0 SD and +3.0 SD and severe obesity: BMI >+3.0 SD.We observed that DD genotype (64.7 %) was prevalent in the moderate undernutrition group, while ID (35.3 %) and II genotypes were higher in the subgroup of severe undernutrition, with significant correlations in DD and ID genotype groups between BMI and MUAC, protein and albumin (p < 0.0001). In the obese group, we observed significant correlations in DD genotype, between BMI and MUAC (p = 0.0014) and TST, and for II genotype, between BMI and TST (p = 0.0071). II genotype was associated with severe obesity, while D allele carriers were associated with moderate undernutrition and moderate obesity.BMI, MUAC, TST and serum protein levels are correlated with D allele carriers of ACE genes in children with moderate undernutrition and moderate obesity, whereas II genotype is an unfavorable prognostic factor corresponding to severe obesity and severe undernutrition.
Keywords: Children; ACE I/D polymorphism; Undernutrition; Obesity
Apigenin manipulates the ubiquitin–proteasome system to rescue estrogen receptor-β from degradation and induce apoptosis in prostate cancer cells by Vishal Singh; Vikas Sharma; Vikas Verma; Deepti Pandey; Santosh K. Yadav; Jagdamba P. Maikhuri; Gopal Gupta (1255-1267).
To investigate apigenin (5,7,4-trihydroxyflavone), a dietary flavonoid with proteasome-inhibitory activity (desired for the management of multiple types of cancers), against FDA-approved anticancer proteasome inhibitor bortezomib in context to its effects on the tumor suppressor estrogen receptor-beta (ER-β) in prostate cancer cells.Prostate cancer (PC-3) cells were treated with either apigenin or bortezomib, and proliferation inhibition was correlated with proteasomal biochemistry, ER-degradation and cell apoptosis.Apigenin specifically inhibited only chymotrypsin-like activity of proteasome without affecting trypsin and caspase-like activities, which was in contrast to the non-specific inhibition of all the three activities by bortezomib. Apigenin selectively increased the protein levels of ER-β at 1.8 and 10.0 µM (without affecting mRNA levels) and preferentially accumulated ubiquitinated ER-β over ER-α in PC-3. Apigenin-treated cells exhibited increased ER-β interactions with ubiquitin-protein ligase E6AP, downregulated PSMA5 (α-5 subunit for assembly of 20S proteasome) without affecting PSMB1 (β-1 subunit), PSMB2 (β-2 subunit) and PSMB5 (β-5 subunit, whose overexpression by bortezomib causes drug resistance) of proteasome at mRNA levels. Caspase-3 activation in PC-3 by apigenin was dependent on caspase-8 activity but independent of mitochondrial membrane depolarization. The deubiquitinase USP14 activity, which antagonizes degradation of proteins via proteasome, was significantly increased by apigenin treatment.Apigenin selectively inhibits proteasomal degradation of tumor suppressor ER-β by specifically inhibiting chymotrypsin-like activity of proteasome, preventing its assembly via PSMA5 and inhibiting USP14 enzyme activity in prostate cancer cells, resulting in cancer cell apoptosis. Unlike bortezomib, apigenin’s actions are subtle, precise, mechanistically distinct and capable of abstaining drug resistance.
Keywords: Apigenin; Proteasome; Ubiquitination; Estrogen receptor-beta; Bortezomib; Prostate cancer
Prospective relevance of fruit and vegetable consumption and salt intake during adolescence for blood pressure in young adulthood by Danika Krupp; Lijie Shi; Sarah Egert; Stefan A. Wudy; Thomas Remer (1269-1279).
Fruit and vegetable (FV) consumption and salt intake are known dietary influences on blood pressure (BP) in adults, but data on their long-term relevance during growth for later BP are rare. We aimed to examine the independent and concomitant influences of adolescent FV and salt intakes on BP in young adulthood. In total, 206 participants (108 males) provided a plausible BP measurement in young adulthood (18–25 years) as well as three repeated 3-day weighed dietary records, 24-h urine samples and BP measurements during adolescence (11–16 years). FV intake was assessed based on dietary records and its urinary biomarkers such as potassium, oxalate and hippuric acid. Urinary sodium chloride (NaCl) was used to estimate salt intake. Prospective associations of adolescent FV and salt intake with adult BP were examined in sex-stratified linear regression models.In multivariable models, a 100 g higher FV intake during adolescence was prospectively related to 0.9 mmHg lower systolic BP in young adult females (P = 0.02), but not in males (P = 0.8). Biomarkers supported the findings for FV regarding systolic BP. Concurrently, a 1 g higher salt intake was related to 1.7 mmHg higher systolic BP in young men only (P = 0.01). For diastolic BP, results were inconsistent.Our findings suggest that in adolescent healthy girls, a higher FV intake may be more relevant for BP than a reduced salt intake and the opposite appears to apply for boys. The physiological implications of the observed sex-specific diet–BP relationships need deeper examination.
Keywords: Fruit and vegetables; Salt; Blood pressure; Adolescents; Prospective; Biomarker
Glycemic potency of muffins made with wheat, rice, corn, oat and barley flours: a comparative study between in vivo and in vitro by Yean Yean Soong; Rina Yu Chin Quek; Christiani Jeyakumar Henry (1281-1285).
Muffins made with wheat flour are a popular snack consumed in western and emerging countries. This study aimed to examine the content of amylose, glycemic response (GR) and glycemic index (GI) of muffins baked with refined wheat and rice flours, as well as wholegrain corn, oat and barley flours.This study adopted a randomized, controlled, crossover, non-blind design. Twelve healthy participants consumed wheat, rice, corn, oat and barley muffins once and the reference glucose solution three times in a random order on non-consecutive day. Capillary blood samples were taken every 15 min in the first 60 min and every 30 min for the remaining 60 min for blood glucose analysis. The Megazyme amylose/amylopectin assay procedure was employed to measure amylose content.The GR elicited from the consumption of wheat, rice and corn muffins was comparable between these samples but significantly greater when compared with oat and barley muffins. Consumption of wholegrain muffins, apart from corn muffin, blunted postprandial GR when compared with muffins baked with refined cereal flours. Muffins baked with wheat, rice, corn, oat and barley flours gave rise to GI values of 74, 79, 74, 53 and 55, respectively. The content of amylose was significantly higher in corn, oat and barley muffins than wheat and rice muffins.The greater content of amylose and fibre may play a part in the reduced glycemic potency of oat and barley muffins. Wheat flour can be substituted with oat and barley flours for healthier muffins and other bakery products.
Keywords: Amylose; Cereal grains; Glycemic index; Glycemic response
Inhibitory and synergistic effects of natural olive phenols on human platelet aggregation and lipid peroxidation of microsomes from vitamin E-deficient rats by Fátima Rubio-Senent; Baukje de Roos; Garry Duthie; Juan Fernández-Bolaños; Guillermo Rodríguez-Gutiérrez (1287-1295).
This study explored the in vitro antioxidant and anti-platelet activities of hydroxytyrosol, hydroxytyrosol acetate, 3,4-dihydroxyphenylglycol and two phenolic olive extracts. These compounds and extracts were obtained from a new industrial process to hydrothermally treat the alperujo (160 °C/60 min), a by-product of olive oil extraction. The extracts and the purified compounds were obtained chromatographically using both ionic and adsorbent resins. The antioxidant activity was determined by measuring inhibition of human platelet aggregation and inhibition of lipid peroxidation in liver microsomes of vitamin E-deficient rats.The positive effect of the extracts on the inhibition of platelet aggregation is showed, being higher in the case of hydroxytyrosol acetate up to 38 %, and for the first time, its synergist effect with hydroxytyrosol has been proved, obtaining more than double of inhibition. The phenolic extracts and the isolated phenols showed good results for inhibiting the lipid oxidation, up to 62 and 25 %, respectively. A synergistic effect occurred when the hydroxytyrosol acetate and the 3,4-dihydroxyphenylglycol were supplemented by hydroxytyrosol.These results suggest the extract and these compounds obtained from a novel industrial process could be natural alternatives for the prevention of diseases related to cardiovascular disorder or oxidative damage.
Keywords: Alperujo; Olive oil wastes; Phenols; Platelet function; Lipid peroxidation; Vitamin E
Cinnamaldehyde is the main mediator of cinnamon extract in mast cell inhibition by Yvonne Hagenlocher; Kristina Kießling; Michael Schäffer; Stephan C. Bischoff; Axel Lorentz (1297-1309).
In terms of their involvement in allergic and inflammatory conditions, mast cells (MC) can be promising targets for medical agents in therapy. Because of their good compliance and effectiveness, phytochemicals are of great interest as new therapeutic tools in form of nutraceuticals. We found recently that cinnamon extract (CE) inhibits mast cell activation. Here, we analysed the effects of a major compound of CE, cinnamaldehyde (CA), on mast cell activation.Release of prestored and de novo synthesised mediators as well as expression of pro-inflammatory cytokines and mast cell-specific proteases were analysed in RBL-2H3 cells or in human mast cells isolated from intestinal tissue (hiMC) treated with CA prior to stimulation by FcεRI crosslinking or IONO/PMA. The results were compared with the corresponding effects of CE.Following treatment with CA, release of β-hexosaminidase in IgE-dependent or IgE-independent activated RBL-2H3 cells was down-regulated in a dose-dependent manner to about 10 %. In hiMC, release of β-hexosaminidase was also significantly reduced, and release of LTC4 and CXCL8 was almost completely inhibited by CA. Moreover, IgE-mediated expression of CXCL8, CCL2, CCL3 and CCL4 in hiMC was significantly down-regulated by CA. With the exception of the expression of the mast cell proteases tryptase and chymase, the inhibitory effects of CA were very similar to the effects shown for CE treatment. The reducing effect of CA on mast cell mediators—seen for long- and for short-term incubations—could be related to particular signalling pathways as CA caused a down-regulation in ERK as well as PLCγ1 phosphorylation.CA decreases release and expression of pro-inflammatory mast cell mediators. This inhibitory action is similar to the effects observed for CE indicating CA as the main active compound in CE leading to its anti-allergic properties.
Keywords: Mast cells; Allergy; Nutraceuticals; Cinnamaldehyde; Cinnamon extract
Mediterranean diet and cognitive decline over time in an elderly Mediterranean population by Antonia Trichopoulou; Andreas Kyrozis; Marta Rossi; Michalis Katsoulis; Dimitrios Trichopoulos; Carlo La Vecchia; Pagona Lagiou (1311-1321).
Evidence suggests that dietary patterns compatible with the traditional Mediterranean diet (MD) may protect against cognitive decline. We prospectively assessed whether adherence to MD in the Mediterranean country of Greece is inversely associated with cognitive decline in the elderly and whether any particular MD component may play a key role.Elderly men and women (N = 401) residing in the greater Athens area had dietary variables ascertained in 1994–1999. Adherence to MD was represented by the MD score [MDS, 0–3 (low), 4–5 (intermediate), 6–9 (high)]. The mini-mental state examination (MMSE) was administered by trained professionals to individuals aged 65 years or older in 2004–2006 (first assessment) and re-administered in 2011–2012 (second assessment). MMSE change (cMMSE) was categorized as: improved/unchanged (cMMSE ≥ 0), mildly lower (cMMSE −1 to −4) or substantially lower (cMMSE ≤ −5). Associations were evaluated through multinomial logistic regression.Decline in MMSE performance was inversely associated with adherence to MD. For mild versus no decline, odds ratio (OR) comparing high to low MD adherence was 0.46 [95 % confidence interval (CI) 0.25–0.87, p = 0.012]. For substantial versus no decline, OR comparing high to low MD adherence was 0.34 (95 % CI 0.13–0.89, p = 0.025). Among the nine MDS components, only vegetable consumption exhibited a significant inverse association with cognitive decline.Closer adherence to the traditional MD is highly likely to protect against cognitive decline in this elderly Mediterranean population. Higher vegetable consumption appears to play a key role, possibly in synergy with additional components of the diet.
Keywords: Mediterranean diet; Cognitive function; Elderly; Cognition; Dementia
The influence of the menstrual cycle on energy balance and taste preference in Asian Chinese women by Sarah A. Elliott; Janet Ng; Melvin Khee-Shing Leow; Christiani J. K. Henry (1323-1332).
In Caucasian women, research has shown that energy balance and taste preference change throughout the menstrual cycle. However, the contributory role of the menstrual cycle to obesity and insulin resistance among Asian women remains unclear. We investigate the impact of the menstrual cycle on energy balance and taste preference in Singaporean Chinese females.Thirty-one healthy young Chinese female subjects with regular menstrual cycles were recruited. Anthropometrics, body composition, energy intake, resting metabolic rate, premenstrual syndrome (PMS) severity and taste preference to sucrose were assessed during three phases (menses, follicular and luteal), over one (N = 18) to two (N = 13) menstrual cycles.For all subjects (N = 31), we found significant reductions in energy, fat intake (p < 0.05) and taste preference for sucrose (p < 0.05) in the luteal phase compared to early follicular phase as far as Cycle 1 is concerned. No significant differences were observed for carbohydrate and protein intake as well as PMS score. In those evaluated for two full cycles (N = 13), we found that taste preference for sucrose and PMS score were significantly higher in the menstrual phase in Cycle 2 (p < 0.05). No significant differences were observed in energy and macronutrient intake throughout Cycle 2. RMR was similar across the three phases. However, non-significant cyclic variations were noted within and between the cycles.Cyclic variations in energy intake and expenditure contributed by sensory and behavioural changes occur during the menstrual cycle. Whether this contributes to cyclic weight gain is speculative and remains to be proven. Further research in non-Caucasians spanning more than one menstrual cycle is needed to establish the impact of the menstrual cycle on taste preference and energy balance.
Keywords: Energy balance; Taste preference; Premenstrual syndrome; Menstrual cycle
Persimmon tannin represses 3T3-L1 preadipocyte differentiation via up-regulating expression of miR-27 and down-regulating expression of peroxisome proliferator-activated receptor-γ in the early phase of adipogenesis by Bo Zou; Zhenzhen Ge; Wei Zhu; Ze Xu; Chunmei Li (1333-1343).
Currently, obesity has become a worldwide health problem. Adipocyte differentiation is closely associated with the onset of obesity. Our previous studies suggested that persimmon tannin might be a potent anti-adipogenic dietary bioactive compound. However, the mechanism of persimmon tannin on adipocyte differentiation is still unknown. The purpose of this study was to investigate the effect of persimmon tannin on adipogenic differentiation in 3T3-L1 preadipocytes and the underlying mechanisms.Adipogenic differentiation was induced by cocktail in the presence or absence of persimmon tannin. Intracellular lipid accumulation was determined by Oil red O staining and enzymatic colorimetric methods. Gene expression and protein levels were measured by real time RT-PCR and Western blot. Persimmon tannin inhibited intracellular lipid accumulation markedly, and the inhibitory effect was largely limited to the early stage of adipocyte differentiation. Persimmon tannin suppressed the expression of C/EBPα and peroxisome proliferator-activated receptor-γ (PPARγ), significantly. Furthermore, genes related to lipogenesis, such as sterol regulatory element-binding protein 1, were down-regulated by persimmon tannin. In addition, adipocyte fatty acid binding protein (aP2), which is a target gene of PPARγ, was suppressed by persimmon tannin notably. Correspondingly, the expression of miR-27a and miR-27b were up-regulated by persimmon tannin from Day 2 to Day 8 significantly.Persimmon tannin inhibited adipocyte differentiation through regulation of PPARγ, C/EBPα and miR-27 in early stage of adipogenesis.
Keywords: Persimmon tannin; Adipogenesis; PPARγ; Mitotic clonal expansion
Iron bioavailability from commercially available iron supplements by Tatiana Christides; David Wray; Richard McBride; Rose Fairweather; Paul Sharp (1345-1352).
Iron deficiency anaemia (IDA) is a global public health problem. Treatment with the standard of care ferrous iron salts may be poorly tolerated, leading to non-compliance and ineffective correction of IDA. Employing supplements with higher bioavailability might permit lower doses of iron to be used with fewer side effects, thus improving treatment efficacy. Here, we compared the iron bioavailability of ferrous sulphate tablets with alternative commercial iron products, including three liquid-based supplements.Iron bioavailability was measured using Caco-2 cells with ferritin formation as a surrogate marker for iron uptake. Statistical analysis was performed using one-way ANOVA followed by either Dunnett’s or Tukey’s multiple comparisons tests.Spatone Apple® (a naturally iron-rich mineral water with added ascorbate) and Iron Vital F® (a synthetic liquid iron supplement) had the highest iron bioavailability. There was no statistical difference between iron uptake from ferrous sulphate tablets, Spatone® (naturally iron-rich mineral water alone) and Pregnacare Original® (a multimineral/multivitamin tablet).In our in vitro model, naturally iron-rich mineral waters and synthetic liquid iron formulations have equivalent or better bioavailability compared with ferrous iron sulphate tablets. If these results are confirmed in vivo, this would mean that at-risk groups of IDA could be offered a greater choice of more bioavailable and potentially better tolerated iron preparations.
Keywords: Iron supplements; Anaemia; Pregnancy; Bariatric surgery; Micronutrient deficiency; Caco-2 cells
Short-term moderate exercise provides long-lasting protective effects against metabolic dysfunction in rats fed a high-fat diet by Laize Peron Tófolo; Tatiane Aparecida da Silva Ribeiro; Ananda Malta; Rosiane Aparecida Miranda; Rodrigo Mello Gomes; Júlio Cezar de Oliveira; Latifa Abdennebi-Najar; Douglas Lopes de Almeida; Amanda Bianchi Trombini; Claudinéia Conationi da Silva Franco; Audrei Pavanello; Gabriel Sergio Fabricio; Wilson Rinaldi; Luiz Felipe Barella; Paulo Cezar de Freitas Mathias; Kesia Palma-Rigo (1353-1362).
A sedentary lifestyle and high-fat feeding are risk factors for cardiometabolic disorders. This study determined whether moderate exercise training prevents the cardiometabolic changes induced by a high-fat diet (HFD).Sixty-day-old rats were subjected to moderate exercise three times a week for 30 days. After that, trained rats received a HFD (EXE-HFD) or a commercial normal diet (EXE-NFD) for 30 more days. Sedentary animals also received the diets (SED-HFD and SED-NFD). Food intake and body weight were measured weekly. After 120 days of life, analyses were performed. Data were analysed with two-way ANOVA and the Tukey post-test.Body weight gain induced by HFD was attenuated in trained animals. HFD reduced food intake by approximately 30 % and increased body fat stores by approximately 75 %. Exercise attenuated 80 % of the increase in fat pads and increased 24 % of soleus muscle mass in NFD animals. HFD induced a hyper-response to glucose injection, and exercise attenuated this response by 50 %. Blood pressure was increased by HFD, and the beneficial effect of exercise in reducing blood pressure was inhibited by HFD. HFD increased vagal activity by 65 % in SED-HFD compared with SED-NFD rats, and exercise blocked this increase. HFD reduced sympathetic activity and inhibited the beneficial effect of exercise on ameliorating sympathetic activity.Four weeks of moderate exercise at low frequency was able to prevent the metabolic changes induced by a HFD but not the deleterious effects of diet on the cardiovascular system.
Keywords: Exercise; High-fat diet; Obesity; Cardiometabolic syndrome; Autonomic nervous system
Higher plasma lipopolysaccharide concentrations are associated with less favorable phenotype in overweight/obese men by Ana Paula Boroni Moreira; Raquel Duarte Moreira Alves; Tatiana Fiche Salles Teixeira; Viviane Silva Macedo; Leandro Licursi de Oliveira; Neuza Maria Brunoro Costa; Josefina Bressan; Maria do Carmo Gouveia Peluzio; Richard Mattes; Rita de Cássia Gonçalves Alfenas (1363-1370).
Lipopolysaccharide (LPS) from the outer membrane of gram-negative bacteria might be an inflammation trigger in adipose tissue. It has recently been proposed that there is a link between adipose tissue distribution and blood LPS. However, the number of studies on this topic is scarce, and further investigation in humans is required. In this study, we explored the association between plasma LPS concentrations and body fat distribution, as well as the biochemical parameters that may indicate the presence of metabolic disorders.Sixty-seven young adult men with body mass index of 26–35 kg/m2 were evaluated. Anthropometry, body composition and body fat distribution, blood pressure, energy expenditure, physical activity level, dietary intake, and biochemical parameters were assessed.Men with median plasma LPS ≥ 0.9 EU/mL presented higher sagittal abdominal diameter, trunk fat percentage, and android fat percentage, and mass, insulin and alanine aminotransferase concentrations, homeostasis model assessment of insulin resistance (HOMA-IR), and beta cell dysfunction (HOMA-B) than those with lower plasma LPS. LPS correlated positively with the trunk fat percentage, and android fat percentage, and mass, insulin, aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase concentrations, as well as HOMA-IR and HOMA-B.Our results suggest that a higher plasma LPS concentration is associated with a less favorable phenotype as characterized by higher central adiposity, higher values of HOMA-IR, and beta cell function impairment in overweight/obese men.
Keywords: Lipopolysaccharide; Abdominal obesity; Insulin; Homeostasis model assessment
Analysis of microsamples of human faeces: a non-invasive approach to study the bioavailability of fat-soluble bioactive compounds by E. Hernandez-Alvarez; B. I. Pérez-Sacristán; I. Blanco-Navarro; E. Donoso-Navarro; R. A. Silvestre-Mardomingo; F. Granado-Lorencio (1371-1378).
Bioavailability is a critical feature in the assessment of the role of micronutrients in human health. Poorly bioavailable micronutrients like carotenoids may reach significant concentrations in the gastrointestinal tract where they may exert biological actions.We evaluated a simple collection protocol to determine vitamin A, E and carotenoids in microsamples of human faeces as a non-invasive approach for nutritional studies.Microsamples of human faeces were collected using a commercially available device, extracted and analysed on two LC systems. Suitability of the protocol was assessed by evaluating several factors including the effect of simulated colonic conditions and two nutritional scenarios with different dietary components, chemical forms, nutritional goals and target groups.The protocol was reproducible and representative of a faeces sample. The major dietary and serum carotenoids, and several “unidentified” compounds (possibly metabolites) could be detected, and cis-/trans-β-carotene profile reflected dietary intervention. In faeces of neonates, free retinol, retinyl and α-tocopheryl acetate (from infant formula), long-chain fatty acid retinyl esters (from human milk), free γ-tocopherol and α-tocopherol could be detected.Our results show that the analysis of vitamin A, E and carotenoids in microsamples of human faeces is a suitable, non-invasive approach that may provide relevant information regarding responsiveness, nutrient stability and metabolism and may help assess adequacy of chemical forms and delivery systems reaching the colon.
Keywords: Human faeces; Carotenoids; Vitamin A; Vitamin E