Exploration of isoxanthohumol bioconversion from spent hops into 8-prenylnaringenin using resting cells of Eubacterium limosum

Hops is an almost unique source of the potent phytoestrogen 8-prenylnaringenin (8-PN). As hops contain only low levels of 8-PN, synthesis may be more attractive than extraction. A strain of the Gram-positive Eubacterium limosum was isolated previously for 8-PN production from more abundant precursor isoxanthohumol (IX) from hops. In this study, spent hops, an industrial side stream from the beer industry, was identified as interesting source of IX. Yet, hop-derived compounds are well-known antibacterial agents and the traces of a large variety of different compounds in spent hops interfered with growth and IX conversion. Critical factors to finally enable bacterial 8-PN production from spent hops, using a food and feed grade medium, were evaluated in this research. The use of bacterial resting cells and complex medium at a pH of 7.8-8 best fulfilled the requirements for 8-PN production and generated a solid basis for development of an economic process

Novel approaches for analysing gut microbes and dietary polyphenols: challenges and opportunities

Polyphenols, ubiquitously present in the food we consume, may modify the gut microbial composition and/or activity, and moreover, may be converted by the colonic microbiota to bioactive compounds that influence host health. The polyphenol content of fruit and vegetables and derived products is implicated in some of the health benefits bestowed on eating fruit and vegetables. Elucidating the mechanisms behind polyphenol metabolism is an important step in understanding their health effects. Yet, this is no trivial assignment due to the diversity encountered in both polyphenols and the gut microbial composition, which is further confounded by the interactions with the host. Only a limited number of studies have investigated the impact of dietary polyphenols on the complex human gut microbiota and these were mainly focused on single polyphenol molecules and selected bacterial populations. Our knowledge of gut microbial genes and pathways for polyphenol bioconversion and interactions is poor. Application of specific in vitro or in vivo models mimicking the human gut environment is required to analyse these diverse interactions. A particular benefit can now be gained from next-generation analytical tools such as metagenomics and metatranscriptomics allowing a wider, more holistic approach to the analysis of polyphenol metabolism. Understanding the polyphenol gut microbiota interactions and gut microbial bioconversion capacity will facilitate studies on bioavailability of polyphenols in the host, provide more insight into the health effects of polyphenols and potentially open avenues for modulation of polyphenol bioactivity for host health

Dietary Sources of Fiber Intake and Its Association with Socio-Economic Factors among Flemish Preschool Children

The objectives were to assess total dietary fiber intake, identify the major sources of dietary fiber, and examine its association with socio-economic factors among Flemish preschoolers. Three-day estimated dietary records were collected from a representative sample of preschoolers 2.5–6.5 years old (n = 661; 338 boys, 323 girls). The mean dietary fiber intake (13.4 g/d) was lower than the intake level recommended by the Belgian Superior Health Council (70% boys and 81% girls below the guidelines). The most important contributor was the group of bread and cereals (29.5%), followed by fruits (17.8%), potatoes and grains (16.0%), energy-dense, low-nutritious foods (12.4%), and vegetables (11.8%). Multiple linear regression analyses showed that total fiber intake was associated with maternal education and parents’ employment. Overall, fiber intakes from high-nutritious foods (vegetables and fruits) were higher in preschoolers of higher educated mothers and those with one or both parents being employed. In conclusion, the majority of the preschoolers had dietary fiber intakes below the recommended level. Hence, dietary fiber should be promoted among parents of preschoolers and low socio-economic status families should be addressed in particular

Exploratory analysis of the human breast DNA methylation profile upon soymilk exposure

Upon soy consumption, isoflavone metabolites attain bioactive concentrations in breast tissue possibly affecting health. Though in vitro epigenetic activity of soy metabolites has been described, the in vivo impact on the epigenome is largely unknown. Therefore, in this case-control study, the breast glandular tissue DNA methylome was explored in women undergoing an aesthetic breast reduction. After a run-in phase, 10 generally healthy Belgian or Dutch women received soymilk for 5 days. MethylCap-seq methylation profiles were compared with those of 10 matched controls. Isoflavones and their microbial metabolites were quantified in urine, serum, and glandular breast tissue (liquid chromatography-mass spectrometry) and 17 beta-estradiol in glandular breast tissue (immunoassay). Global DNA methylation levels were obtained for 6 cases and 5 controls using liquid chromatography-mass spectrometry. Although lower MethylCap-seq coverages were observed, mass spectrometry results and computational LINE-1 methylation analysis did not provide evidence supporting global methylation alterations upon treatment. At a false discovery rate of 0.05, no differentially methylated loci were identified. Moreover, a set of previously identified loci was specifically tested, but earlier reported results could not be validated. In conclusion, after a 5-day soymilk treatment, no major general epigenetic reprogramming in breast tissue could be found in this exploratory study

Validity and Reproducibility of a Self-Administered Semi-Quantitative Food-Frequency Questionnaire for Estimating Usual Daily Fat, Fibre, Alcohol, Caffeine and Theobromine Intakes among Belgian Post-Menopausal Women

A novel food-frequency questionnaire (FFQ) was developed and validated to assess the usual daily fat, saturated, mono-unsaturated and poly-unsaturated fatty acid, fibre, alcohol, caffeine, and theobromine intakes among Belgian post-menopausal women participating in dietary intervention trials with phyto-oestrogens. The relative validity of the FFQ was estimated by comparison with 7 day (d) estimated diet records (EDR, n 64) and its reproducibility was evaluated by repeated administrations 6 weeks apart (n 79). Although the questionnaire underestimated significantly all intakes compared to the 7 d EDR, it had a good ranking ability (r 0.47–0.94; weighted κ 0.25–0.66) and it could reliably distinguish extreme intakes for all the estimated nutrients, except for saturated fatty acids. Furthermore, the correlation between repeated administrations was high (r 0.71–0.87) with a maximal misclassification of 7% (weighted κ 0.33–0.80). In conclusion, these results compare favourably with those reported by others and indicate that the FFQ is a satisfactorily reliable and valid instrument for ranking individuals within this study population

Fibre intake among the Belgian population by sex-age and sex-education groups and its association with BMI and waist circumference

The objectives of the present study were to assess total dietary fibre intake and the main contributors to fibre intake in the Belgian population by sex-age and sex-education groups and to investigate its relationship with BMI and waist circumference (WC). The participants of the Belgian food consumption survey (2004) were randomly selected. Information about food intake was collected using two repeated, non-consecutive 24 h recall interviews. A total of 3083 individuals (>= 15 years; 1546 men and 1537 women) completed both interviews. The main contributors to total fibre intake (17.8 g/d) were cereals and cereal products (34%; 5.9 g/d), potatoes and other tubers (18.6%; 3.3 g/d), fruits (14.7%; 2.8 g/d) and vegetables (14.4%; 2.6 g/d). Legume fibre intake was extremely low (0.672%; 0.139 g/d). In all sex-age and sex-education groups, total fibre intake was below the recommendations of the Belgian Superior Health Council. Men (21 g/d) consumed significantly more fibre than women (17.3 g/d) (P < 0.001). Lower educated men and higher educated women reported the highest fibre intake. A significant inverse association was found between total fibre intake and WC (beta = -0.118, P < 0.001). Fruit-derived fibre was positively associated with WC (beta = 0.731, P=0.001). In summary, total fibre intake was inversely associated with WC, whereas fruit-derived fibre intake was positively associated with WC in the Belgian population

Microbial and dietary factors associated with the 8-prenylnaringenin producer phenotype: a dietary intervention trial with fifty healthy post-menopausal Caucasian women

Hop-derived food supplements and beers contain the prenylflavonoids xanthohumol (X), isoxanthohumol (IX) and the very potent phyto-oestrogen (plant-derived oestrogen mimic) 8-prenylnaringenin (8-PN). The weakly oestrogenic IX can be bioactivated via O-demethylation to 8-PN. Since IX usually predominates over 8-PN, human subjects may be exposed to increased doses of 8-PN. A dietary intervention trial with fifty healthy postmenopausal Caucasian women was under-taken. After a 4 d washout period, participants delivered faeces, blank urine and breath samples. Next, they started a 5 d treatment with hop-based supplements that were administered three times per d and on the last day, a 24 h urine sample was collected. A semi-quantitative FFQ was used to estimate fat, fibre, alcohol, caffeine and theobromine intakes. The recoveries of IX, 8-PN and X in the urine were low and considerable inter-individual variations were observed. A five-fold increase in the dosage of IX without change in 8-PN concentration resulted in a significant lower IX recovery and a higher 8-PN recovery. Classification of the subjects into poor (60 %), moderate (25 %) and strong (15 %) 8-PN producers based on either urinary excretion or microbial bioactivation capacity gave comparable results. Recent antibiotic therapy seemed to affect the 8-PN production negatively. A positive trend between methane excretion and 8-PN production was observed. Strong 8-PN producers consumed less alcohol and had a higher theobromine intake. From this study we conclude that in vivo O-demethylation of IX increases the oestrogenic potency of hop-derived products

Plant and animal protein intake and its association with overweight and obesity among the Belgian population

The objective of the present study was to assess animal and plant protein intakes in the Belgian population and to examine their relationship with overweight and obesity (OB). The subjects participated in the Belgian National Food Consumption Survey conducted in 2004. Food consumption was assessed by using two non-consecutive 24 h dietary recalls. About 3083 participants (>= 15 years of age; 1546 males, 1537 females) provided completed dietary information. Animal protein intake (47 g/d) contributed more to total protein intakes of 72 g/d than plant protein intake, which accounted for 25 g/d. Meat and meat products were the main contributors to total animal protein intakes (53%), whereas cereals and cereal products contributed most to plant protein intake (54%). Males had higher animal and plant protein intakes than females (P < 0.001). Legume and soya protein intakes were low in the whole population (0.101 and 0.174 g/d, respectively). In males, animal protein intake was positively associated with BMI (beta = 0.013; P = 0.001) and waist circumference (WC; beta = 0.041; P = 0.002). Both in males and females, plant protein intake was inversely associated with BMI (males: beta = -0.036; P < 0.001; females: beta = -0.046; P = 0.001) and WC (male: beta = -0.137; P < 0.001; female: beta = -0.096; P = 0.024). In conclusion, plant protein intakes were lower than animal protein intakes among a representative sample of the Belgian population and decreased with age. Associations with anthropometric data indicated that plant proteins could offer a protective effect in the prevention of overweight and OB in the Belgian population

A Nine-Strain Bacterial Consortium Improves Portal Hypertension and Insulin Signaling and Delays NAFLD Progression In Vivo

Bacterial consortium; Gut microbiome; Portal hypertensionConsorcio bacteriano; Microbioma intestinal; Hipertensión portalConsorci bacterià; Microbioma intestinal; Hipertensió portalThe gut microbiome has a recognized role in Non-alcoholic fatty liver disease (NAFLD) and associated comorbidities such as Type-2 diabetes and obesity. Stool transplantation has been shown to improve disease by restoring endothelial function and insulin signaling. However, more patient-friendly treatments are required. The present study aimed to test the effect of a defined bacterial consortium of nine gut commensal strains in two in vivo rodent models of Non-alcoholic steatohepatitis (NASH): a rat model of NASH and portal hypertension (PHT), and the Stelic animal (mouse) model (STAM™). In both studies the consortium was administered orally q.d. after disease induction. In the NASH rats, the consortium was administered for 2 weeks and compared to stool transplant. In the STAM™ study administration was performed for 4 weeks, and the effects compared to vehicle or Telmisartan at the stage of NASH/early fibrosis. A second group of animals was followed for another 3 weeks to assess later-stage fibrosis. In the NASH rats, an improvement in PHT and endothelial function was observed. Gut microbial compositional changes also revealed that the consortium achieved a more defined and richer replacement of the gut microbiome than stool transplantation. Moreover, liver transcriptomics suggested a beneficial modulation of pro-fibrogenic pathways. An improvement in liver fibrosis was then confirmed in the STAM™ study. In this study, the bacterial consortium improved the NAFLD activity score, consistent with a decrease in steatosis and ballooning. Serum cytokeratin-18 levels were also reduced. Therefore, administration of a specific bacterial consortium of defined composition can ameliorate NASH, PHT, and fibrosis, and delay disease progression