Lawrence T. Weaver

Isolation of Helicobacter pylori from human faeces

Helicobacter pylori is arguably the commonest chronic infection in man. However, its route of transmission is unknown. We have isolated viable H pylori from the faeces of an infected individual from The Gambia. The organism was cultured on selective media after concentration of faecal bacteria by centrifugation in a buffer equilibrated with a microaerophilic gas mixture. Growth characteristics, microscopic appearances, and enzyme activities were the same as those of a typical gastric isolate of H pylori. Protein preparations derived from the new isolate and the typical strain were antigenically similar, and had very similar electrophoretic profiles (including two major protein bands of 62 and 26 kDa, corresponding to the urease enzyme subunits). With the same technique, organisms with the colony morphology, growth requirements, enzyme activities, and microscopic appearances of H pylori were isolated from the faeces of 9 of 23 randomly selected children aged 3-27 months from a Gambian village with a high prevalence of H pylori infection in early life. Faecal-oral transmission is probably important in the spread of infection in such communities.

Dietary products used in infants for treatment and prevention of food allergy.: Joint statement of the European Society for Paediatric Allergology and Clinical Immunology (ESPACI) Committee on Hypoallergenic Formulas and the European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) Committee on Nutrition

For more than 50 years, many children with food protein allergies and other forms of dietary protein intolerance have been treated successfully with protein hydrolysates with highly reduced allergenicity and, more recently, also with products based on amino acid mixtures. Strategies for the prevention of allergy have been proposed, including the use of products with extensively reduced allergenicity. Products designed to have a moderately reduced allergenicity have also been proposed and marketed in Europe as hypoallergenic formulas. The European Society for Paediatric Allergology and Clinical Immunology (ESPACI) and the European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) have commented previously on these issues,1 2 and the Commission of the European Union has issued a regulation for the requirements of infant formulas with reduced allergenicity or reduced antigenicity.3 This paper comments on the current developments and unresolved issues in the dietary treatment and prevention of food allergy in infancy to help inform paediatricians and other health care professionals, as well as manufacturers of infant foods. Adverse reactions to foods are a problem, particularly in infancy and early childhood, and can present with a wide spectrum of clinical reactions such as cutaneous, gastrointestinal, respiratory, or other symptoms. Reproducible adverse reactions to food(s) can be the result of one or more immune mechanism(s) or they can be non-immunologically mediated. Immunologically mediated reactions, which are often immediate IgE mediated reactions, are defined as food protein allergy. Non-immunologically mediated reactions can be divided into enzymatic or transport defects (for example, lactase deficiency, or glucose/galactose malabsorption), pharmacological or other (undefined) reactions.2 4 The pattern and threshold of adverse reactions to foods varies. None of the symptoms related to immunologically or non- immunologically mediated adverse reactions to foods are pathognomonic, and no single laboratory test is diagnostic of food allergy. Therefore, the diagnosis …

Effects on birth weight and perinatal mortality of maternal dietary supplements in rural Gambia: 5 year randomised controlled trial .

Abstract Objective: To test the efficacy in terms of birth weight and infant survival of a diet supplement programme in pregnant African women through a primary healthcare system. Design: 5 year controlled trial of all pregnant women in 28 villages randomised to daily supplementation with high energy groundnut biscuits (4.3MJ/day) for about 20 weeks before delivery (intervention) or after delivery (control). Setting: Rural Gambia. Subjects: Chronically undernourished women (twin bearers excluded), yielding 2047 singleton live births and 35 stillbirths. Main outcome measures: Birth weight; prevalence of low birth weight (<2500 g); head circumference; birth length; gestational age; prevalence of stillbirths; neonatal and postneonatal mortality. Results: Supplementation increased weight gain in pregnancy and significantly increased birth weight, particularly during the nutritionally debilitating hungry season (June to October). Weight gain increased by 201 g (P<0.001) in the hungry season, by 94 g (P<0.01) in the harvest season (November to May), and by 136 g (P<0.001) over the whole year. The odds ratio for low birthweight babies in supplemented women was 0.61 (95% confidence interval 0.47 to 0.79, P<0.001). Head circumference was significantly increased (P<0.01), but by only 3.1 mm. Birth length and duration of gestation were not affected. Supplementation significantly reduced perinatal mortality: the odds ratio was 0.47 (0.23 to 0.99, P<0.05) for stillbirths and 0.54 (0.35 to 0.85, P<0.01) for all deaths in first week of life. Mortality after 7 days was unaffected. Conclusion: Prenatal dietary supplementation reduced retardation in intrauterine growth when effectively targeted at genuinely at-risk mothers. This was associated with a substantial reduction in the prevalence of stillbirths and in early neonatal mortality. The intervention can be successfully delivered through a primary healthcare system. Key messages In developing countries chronic maternal undernutrition is a prime contributor to the birth of over 25 million low birthweight babies annually and to high rates of neonatal mortality. An absence of well designed field trials has created uncertainty about the potential efficacy of maternal feeding programmes This large scale randomised controlled trial shows that dietary supplementation in pregnancy can be highly effective in reducing the proportion of low birthweight babies and perinatal mortality Incorporating supplementary feeding into a rural primary healthcare system is feasible Late pregnancy is the period most amenable to intervention

Probiotic bacteria in dietetic products for infants: A commentary by the ESPGHAN Committee on Nutrition

*University of Milano, Milano, Italy; †University of Lund, Malmo, Sweden; ‡University Children’s Hospital, Zurich, Switzerland (Committee guest); §Hopital Necker Enfants-Malades, Paris, France; Ludwig-Maximilians-University, Munich, Germany (Committee Chair); ¶The Royal Veterinary and Agricultural University, Frederiksberg, Denmark; #University of Liege, Liege, Belgium; **Meyer Children’s Hospital of Haifa, Israel; ††The Medical University of Warsaw, Warsaw, Poland (Committee Secretary); ‡‡University of Lille, Lille, France; §§University of Glasgow, Glasgow, United Kingdom.

Helicobacter pylori Colonization in Early Life

Helicobacter pylori infection is a major cause of upper gastrointestinal disease throughout the world. Colonization begins in childhood, although little is known about its age of onset, rate, or mode of colonization. Our aim was to identify the age of acquisition of H. pylori colonization in Gambian children. A cohort of 248 Gambian children aged 3 to 45 months was studied at intervals of 3 months for 2 years, using the 13C-urea breath test, specific IgM and specific IgG serology. The prevalence of positive breath tests rose from 19% at 3 months of age to 84% by age 30 months. Elevated specific IgG and IgM antibody levels were associated with positive breath tests, although there was discrepancy between breath test results and serology, particularly IgG serology, during the 1st year of life. Neither IgG nor IgM serology could be validated as reliable diagnostic tools for infant H. pylori colonization compared with the 13C-urea breath test. Reversion to negative breath test, in association with declining specific antibody levels, occurred in 48/248 (20%) of children. On the assumption that the 13C-urea breath test is a reliable index of H. pylori colonization, we conclude that the infection is extremely common from an early age in Gambian children. Transient colonization may occur. Previous studies relying on serodiagnosis may have significantly underestimated the true early prevalence of colonization in the developing world, where the target age for intervention studies is probably early infancy.

Maternal docosahexaenoic acid supplementation during pregnancy and visual evoked potential development in term infants: a double blind, prospective, randomised trial

Aim: To test the hypothesis that maternal docosahexaenoic acid (DHA) supplementation during pregnancy enhances maturation of the visual evoked potential (VEP) in healthy term infants. Methods: One hundred women were supplemented with either fish oil capsules rich in DHA (n = 50) or placebo capsules (n = 50) from week 15 of pregnancy until delivery. Total fatty acids in red blood cells and plasma were measured at weeks 15, 28, and 40 of pregnancy and at delivery in umbilical cord blood. Infant visual pathway development was assessed using VEPs recorded to flash stimuli shortly after birth and to both flash and pattern-reversal stimuli at 50 and 66 weeks post-conceptional age (PCA). Results: Maternal supplementation did not significantly elevate the level of DHA in umbilical cord blood. Moreover, there were no significant differences in any of the VEP measures observed between supplementation groups. However, maturity of the pattern-reversal VEP at 50 and 66 weeks PCA was associated with DHA status of the infants at birth. Infants with higher DHA status, both as a concentration and as a percentage of total fatty acids, showed shorter P100 peak latencies of the pattern-reversal VEP than those with lower DHA status. Conclusions: Maternal DHA supplementation during pregnancy did not enhance VEP maturation in healthy term infants. However, these results show an association between the DHA status of infants at term and early postnatal development of the pattern-reversal VEP, suggesting that DHA status itself may influence maturation of the central visual pathways.

Nutrition in infancy and long-term risk of obesity: evidence from 2 randomized controlled trials

BACKGROUND Growth acceleration as a consequence of relative overnutrition in infancy has been suggested to increase the risk of later obesity. However, few studies have investigated this association by using an experimental study design. OBJECTIVE We investigated the effect of early growth promotion on later body composition in 2 studies of infants born small for gestational age (weight <10th percentile in study 1 and <20th percentile in study 2). DESIGN We reviewed a subset of children (n = 153 of 299 in study 1 and 90 of 246 in study 2) randomly assigned at birth to receive either a control formula or a nutrient-enriched formula (which contained 28-43% more protein and 6-12% more energy than the control formula) at 5-8 y of age. Fat mass was measured by using bioelectric impedance analysis in study 1 and deuterium dilution in study 2. RESULTS Fat mass was lower in children assigned to receive the control formula than in children assigned to receive the nutrient-enriched formula in both trials [mean (95% CI) difference for fat mass after adjustment for sex: study 1: -38% (-67%, -10%), P = 0.009; study 2: -18% (-36%, -0.3%), P = 0.04]. In nonrandomized analyses, faster weight gain in infancy was associated with greater fat mass in childhood. CONCLUSIONS In 2 prospective randomized trials, we showed that a nutrient-enriched diet in infancy increased fat mass later in childhood. These experimental data support a causal link between faster early weight gain and a later risk of obesity, have important implications for the management of infants born small for gestational age, and suggest that the primary prevention of obesity could begin in infancy.

Butyrate production from oligofructose fermentation by the human faecal flora: what is the contribution of extracellular acetate and lactate?

Butyrate is an important substrate for maintenance of colonic health and oligofructose fermentation by human faecal bacteria can increase butyrate production in vitro. However, oligofructose appears to be fermented by mainly acetate and lactate-producing bacteria rather than butyrate-producing bacteria. Isotope labelling studies using [U-(13)C(6)]glucose were used to show that (13)C(2) and (13)C(4) were the major labelled butyrate species produced from glucose fermentation, via [(13)C(2)]acetate-acetyl CoA as intermediate. Bacterial interconversion reactions were quantified and acetate conversion to butyrate and lactate conversion to acetate, propionate and butyrate were observed. Addition of oligofructose to faecal batch cultures significantly increased butyrate production. Of the newly synthesised butyrate from oligofructose fermentation, 80 % was derived from interconversion of extracellular acetate and lactate, with acetate being quantitatively more significant. Carbohydrates, such as oligofructose, have prebiotic properties. In addition, oligofructose selectively stimulates the bacterial conversion of acetate and lactate to butyrate. Carbohydrates with similar properties represent a refinement of the prebiotic definition, termed butyrogenic prebiotics, because of their additional functionality.

Genotype-phenotype analysis in childhood-onset Crohn's disease: NOD2/CARD15 variants consistently predict phenotypic characteristics of severe disease.

Introduction: The incidence of early‐onset CD in Scotland is among the highest worldwide. Three single nucleotide polymorphisms (SNPs) R702W, G908R and Leu1007finsC in the NOD2/CARD15 gene predispose to adult CD. We investigated the contribution of these variants to disease susceptibility and phenotype in the Scottish early‐onset IBD population. Patients and Methods: 906 individuals including 247 Scottish IBD patients aged <16 years at diagnosis, 414 parents and 245 controls were genotyped. Transmission disequilibrium testing (TDT), case‐control analysis and detailed genotype‐phenotype analysis were performed. Results: The Leu1007finsC variant was associated with susceptibility to CD by case‐control (4.2% versus. 1.4%, P = 0.01) and TDT analysis (P = 0.006). The Population Attributable Risk (PAR) for the 3 NOD2/CARD15 mutations was 7.9%. Carriage of NOD2/CARD15 variants was associated with, at diagnosis: decreased albumin (31.0% versus. 9.0%, P = 0.001) and raised CRP (25% versus. 9.5%, P = 0.04) and at follow up: need for surgery (39.5% versus. 12.8%, P = 0.0002) jejunal involvement (50% versus. 18.4%, P = 0.01) jejunal and ileal involvement (50% versus. 10.7%, P = 0.009), raised CRP (57.1% and 12.8%, P = 0.0009), lower weight/height centile (75.0% versus. 20.2%, P = 0.03, 50.0% versus. 16.0%, P = 0.001 respectively) and stricturing disease (45.5% versus. 19.4%, P < 0.05). Multifactorial analysis demonstrated carriage was associated with need for surgery (P = 0.004, OR 4.9 [1.5‐14.7]). Conclusions: These NOD2/CARD 15 variants in the Scottish early onset CD population have a definite, albeit relatively small contribution to CD susceptibility (PAR 7.9%) but a major impact on phenotype. In particular NOD2/CARD15 variants are strongly associated with several markers of disease severity in pediatric CD, notably need for surgery.

Protection by human milk IgA against Helicobacter pylori infection in infancy

The potential protective effect of specific human milk IgA (gamma-A globulin) was studied in 12 mothers and their infants from a Gambian village in which most infants are breastfed during the first 2 years of life. 6-14 samples of milk were collected from each mother over 9-16 days at 3-8 months postpartum. Helicobacter pylori IgA was measured by enzyme-linked immunosorbent assay (ELISA). 13C-urea breath tests were used to detect H pylori infection in the 12 infants at ages 3 6 9 and 12 months with a test solution containing 100 mg 13C-urea. Breath samples were collected at 0 15 30 and 50 minutes after administration of substrate. Isotopic enrichment in expired breath was expressed as Craig corrected delta relative to the international standard Pee Dee belemnite (PDB) limestone. Children and enrichment of 13C02 in expired breath of 6 or more delta units relative to PDB above baseline at 15 30 and 60 minutes after ingestion of substrate were diagnosed as infected with H pylori. 114 breast milk samples were analyzed. There was a connection between the concentration of specific breast milk IgA and the age of acquisition of H pylori infection. By ranking mothers according to the level of anti-H-pylori IgA they secreted their children could be divided into 2 groups according to whether or not H pylori infection was diagnosed by 9 months of age (p=0.004). All 5 infected children at this age came from the 5 mothers with the lowest specific breast milk IgA. By 12 months of age only 3 children were infection-free including the children of the 2 mothers who produced the highest specific breast milk IgA (p=0.04). Early infection with H pylori may compromise the gastric acid barrier and facilitate the passage of enteropathogenic bacteria from contaminated foods to the immunologically naive infant gut. Specific human milk IgA may be crucial in delaying the onset of H pylori infection and maintaining the integrity of the gastric acid barrier throughout the vulnerable weaning period.