Pulp in Shop-Bought Orange Juice Has Little Effect on Flavonoid Content and Gut Bacterial Flavanone Degradation In Vitro.

Orange juice is an important source of flavanones in the Western diet. However, little is known of the variation in flavanone content of shop-bought orange juice with pulp (OJP) or without pulp (OJ), nor the impact of pulp on the fate of flavanones in the gut. Total phenols, total flavonoids, antioxidant capacity, hesperidin and narirutin, and dietary fibre were measured in six orange juice brands sold as OJP and OJ. The inclusion of pulp had little impact on fibre content. Apart from total phenols (OJ: 208.4 ± 10.7 µg gallic acid equivalents (GAE) ml-1; OJP: 225.9 ± 16.7 µg GAE ml-1, P < 0.05), there were no differences between OJ and OJP. The fate of flavanones in OJ and OJP (Tropicana) were further compared using in vitro gastrointestinal (GI) models. After in vitro upper GI digestion, recovery of hesperidin was higher in OJ compared with OJP (89 ± 6 vs. 68 ± 3%, P = 0.033). After 2 h colonic fermentation, hesperidin was 1.2 fold higher in OJP than OJ. However, after 24 h colonic fermentation there was no significant difference between juices in terms of hesperidin, hesperetin, narirutin, naringenin and catabolites. In conclusion, the amount of pulp included in these shop-bought orange juices had little impact on flavanone metabolism in models of the GI tract. The effects of greater amounts of orange pulp remain to be determined.

Impact of Fermentable Fibres on the Colonic Microbiota Metabolism of Dietary Polyphenols Rutin and Quercetin.

Dietary fibre and polyphenols are both metabolised to short-chain fatty acids (SCFAs) and phenolic acids (PA) by the colonic microbiota. These may alter microbiota growth/diversity, but their interaction is not understood. Interactions between rutin and raftiline, ispaghula or pectin were investigated in human faecal batch cultures (healthy participants; 19⁻33 years, 4 males, 6 females, BMI 18.4⁻27.4) after a low (poly)phenol diet three days prior to study. Phenolic acids were measured by gas chromatography-mass spectrometry and SCFAs by gas chromatography-flame ionisation after 2, 4, 6, and 24 h. Rutin fermentation produced Phenyl acetic acid (PAA), 4-Hydroxy benzoic acid (4-OHBA), 3-Hydroxy phenyl acetic acid (3-OHPAA), 4-Hydroxy phenyl acetic acid (4-OHPAA), 3,4-Dihydroxy phenyl acetic acid (3,4-diOHPAA), 3-Hydroxy phenyl propionic acid (3-OHPPA), and 4-Hydroxy phenyl propionic acid (4-OHPPA). 3,4-DiOHPAA and 3-OHPAA were predominant at 6 h (1.9 ± 1.8 µg/mL, 2.9 ± 2.5 µg/mL, and 0.05 ± 0.0 µg/mL, respectively) and 24 h (5.5 ± 3.3 µg/mL, 3.1 ± 4.2 µg/mL, and 1.2 ± 1.6 µg/mL). Production of all PA except 3-OHPPA and 4-OHPPA was reduced by at least one fibre. Inhibition of PA was highest for rutin (8-fold, p < 0.01), then pectin (5-fold, p < 0.01), and ispaghula (2-fold, p = 0.03). Neither rutin nor quercetin had a detectable impact on SCFA production. These interactions should be considered when assessing dietary polyphenols and potential health benefits.

Determinants and Duration of Impact of Early Gut Bacterial Colonization.

BACKGROUND: An increasing number of studies show low diversity of the gut microbiome in those with chronic diseases such as obesity, inflammatory bowel disease, and allergy. Manipulation of the microbiota may promote health. However, the adult microbiota is stable and may be difficult to change. Understanding the fixed and modifiable factors, which determine colonization in early life, may provide strategies for acquisition of a health-promoting microbiome. SUMMARY: Not enough is known about the long-term effects of established determinants of gut colonization, including delivery mode, perinatal antibiotics, and infant diet. It has been suggested that weaning onto solid diet containing non-digestible carbohydrates and cessation of breastfeeding are key stages in the colonization process. In addition, the microbiome of the placenta, amniotic fluid, and breast milk, alongside vaginal and fecal bacteria, may aid the transfer of maternal bacteria to the infant. However, methodological issues such as contamination during collection and/or analysis should be considered. Key Messages: The factors determining early colonization are becoming more evident. However, longitudinal studies of microbiome maturation into late childhood and adulthood are required. The nutrition and health status of the mother before, during, and after birth may be major factors in the early colonization of the infant.

Role of Gut Microbiota in the Aetiology of Obesity: Proposed Mechanisms and Review of the Literature.

The aetiology of obesity has been attributed to several factors (environmental, dietary, lifestyle, host, and genetic factors); however none of these fully explain the increase in the prevalence of obesity worldwide. Gut microbiota located at the interface of host and environment in the gut are a new area of research being explored to explain the excess accumulation of energy in obese individuals and may be a potential target for therapeutic manipulation to reduce host energy storage. Several mechanisms have been suggested to explain the role of gut microbiota in the aetiology of obesity such as short chain fatty acid production, stimulation of hormones, chronic low-grade inflammation, lipoprotein and bile acid metabolism, and increased endocannabinoid receptor system tone. However, evidence from animal and human studies clearly indicates controversies in determining the cause or effect relationship between the gut microbiota and obesity. Metagenomics based studies indicate that functionality rather than the composition of gut microbiota may be important. Further mechanistic studies controlling for environmental and epigenetic factors are therefore required to help unravel obesity pathogenesis.

Group and individual agreement between field and dual X-ray absorptiometry-based body composition techniques in children from standard schools and a sports academy.

Percentage fat (%FM) and fat-free mass (FFM) were measured in 37 children from a sports academy and in 71 children from standard schools with dual x-ray absorptiometry (DXA) and bioelectrical impedance analysis (BIA) using the manufacturer's equation (Tanita) and an ethnic-specific prediction equation (Haroun). In the standard school, BIA overestimated FFM and underestimated %FM by a mean of 2.5 kg and 5.2%, respectively, using the Tanita equation. In girls from the sports academy, the Tanita equation underestimated FFM and overestimated %FM compared with DXA (mean difference BIA-DXA; FFM: -1.3 kg; %FM: 1.8%). The Haroun equation improved mean agreement between BIA and DXA in children (11 to 15 years) from the sports academy and for boys from standard schools, but reduced accuracy on individual assessments. These results have important practice implications for dietetics practitioners specializing in sports nutrition and exercise trainers.

Impact of exclusive enteral nutrition on body composition and circulating micronutrients in plasma and erythrocytes of children with active Crohn's disease.

BACKGROUND: Nutritional therapy is the primary treatment for active pediatric Crohn's disease (CD) in the UK/Europe, improving disease activity and anthropometry. This study assessed changes in micronutrient status during exclusive enteral nutrition (EEN). METHODS: Seventeen children (male/female: 8/9; median age: 12.7 years) with active CD were treated exclusively for 6-8 weeks on a polymeric feed (Modulen IBD; Nestle, UK). Body impedance was measured at baseline, during EEN, and posttreatment on normal diet and converted to z-scores of fat and lean mass. Blood samples for nutrient analysis were collected from 13 children at baseline, end of EEN, and posttreatment. RESULTS: Lean but not fat mass improved at the end of EEN (initiation vs. end of EEN; fat mass [z-score]: -0.5 vs. -0.3; P = 0.141; lean mass [z-score]: -2.1 vs. -0.8; P < 0.0001). At baseline several children presented with suboptimal concentrations of carotenoids, trace elements, vitamin C, B6, and folate in plasma but not in erythrocytes. EEN improved concentrations for several nutrients, but more than 90% of patients had depleted concentrations of all carotenoids. The latter improved on normal diet but other micronutrients, which improved during EEN, returned toward pretreatment concentrations. CONCLUSIONS: Lean but not fat mass improved at the end of EEN. Median concentrations for several plasma micronutrients improved on EEN but carotenoids were depleted. These findings may have implications for clinical practice and producers of enteral feeds. As plasma concentrations for many micronutrients can be affected by the acute phase response, measurements in erythrocytes may be a better marker of actual body stores.

Serial fecal calprotectin changes in children with Crohn's disease on treatment with exclusive enteral nutrition: associations with disease activity, treatment response, and prediction of a clinical relapse.

BACKGROUND: Exclusive enteral nutrition (EEN) induces clinical remission in pediatric Crohn's disease (CD). GOALS: This study explored changes in fecal calprotectin concentration during treatment with EEN. STUDY: Fecal calprotectin was measured in 4 serial stool samples from CD children during EEN. The Pediatric Crohn's Disease Activity Index (PCDAI) and systemic markers of disease activity were measured at the beginning and end of treatment. RESULTS: Fifteen CD children (7 girls; 11.6±2.3 y) participated. PCDAI decreased in 14 children and 7 children achieved clinical remission (PCDAI ≤10). Fecal calprotectin concentration decreased (30 d, P=0.014; 60 d, P<0.0001) only in those children who entered clinical remission (PCDAI ≤10). In the whole group mean calprotectin concentration at baseline (2158±642 mg/kg) was reduced by 975 mg/kg (95% confidence interval -1783; -167) after 30 days and 1700 mg/kg (95% confidence interval -2508; -892) on EEN completion. Only one child reached normal levels by the end of EEN. Decrease of pretreatment calprotectin levels by more than 18% after 30 days on EEN predicted clinical response at the end of EEN. Calprotectin levels at the end of EEN treatment did not predict the length of time lapsed to a future relapse. CONCLUSIONS: In this pilot study calprotectin decreased in patients who achieved clinical remission and may be useful to predict response to treatment.