Florence Campeotto

Conditions of bifidobacterial colonization in preterm infants : A prospective analysis

Background: Premature birth results in a delayed and abnormal qualitative pattern of gut colonization. This abnormal pattern is thought to affect intestinal development and contribute to a higher risk of gastrointestinal infectious diseases such as neonatal necrotizing enterocolitis (NEC). In particular, bifidobacteria are thought to play a major role. We therefore studied bifidobacterial colonization in preterm infants during the first month of life. Patients and Methods: Fecal samples were prospectively analyzed in 52 infants born at a gestational age ranging from 30 to 35 weeks fed with a preterm formula alone and, in 18, with their mothers milk. Fecal samples were collected twice per week during the hospital stay. Bifidobacterial colonization was analyzed with culture and a molecular method. Results: Bifidobacterial colonization occurred in 18 infants at a median age of 11 days, always greater than the corrected mean gestational age of 35.4 weeks (SD, 0.9) and greater than 34 weeks for 16 of 18. Colonization by bifidobacteria was affected by neither birthweight nor mode of delivery nor antibiotics given to the mother or infant. In contrast, birth gestational age had a significant impact on colonization by bifidobacteria (P < 0.05), which always occurred in children born at a birth gestational age greater than 32.9 weeks (P < 0.05). Conclusions: Birth gestational age seems to act as a major determinant of bifidobacterial colonization in the premature infant, suggesting the role of gut maturation, a finding that should probably be taken into account in manipulations of the gut flora aimed at reducing NEC.

A fermented formula in pre-term infants: clinical tolerance, gut microbiota, down-regulation of faecal calprotectin and up-regulation of faecal secretory IgA

Intestinal bacterial colonisation in pre-term infants is delayed compared with full-term infants, leading to an increased risk of gastrointestinal disease. Modulation of colonisation through dietary supplementation with probiotics or prebiotics could decrease such a risk. The present study evaluated clinical tolerance, the effects on gut microbiota, and inflammatory and immunological mucosal responses to an infant formula adapted for pre-term infants that included in its manufacturing process a fermentation step with two probiotic strains, Bifidobacterium breve C50 and Streptococcus thermophilus 065, inactivated by heat at the end of the process. A total of fifty-eight infants (gestational age: 30-35 weeks), fed either the fermented pre-term formula or a standard pre-term formula, were followed up during their hospital stay. Clinical tolerance, faecal microbiota using a culture and a culture-independent method (temporal temperature gel electrophoresis), faecal calprotectin and secretory IgA were analysed weekly. No difference was observed regarding anthropometric data and digestive tolerance, except for abdominal distension, the incidence of which was lower in infants fed the fermented formula for 2 weeks. Bacterial colonisation was not modified by the type of feeding, particularly for bifidobacteria. Faecal calprotectin was significantly lower in infants fed the fermented formula for 2 weeks, and secretory IgA increased with both mothers milk and the fermented formula. The fermented formula was well tolerated and did not significantly modulate the bacterial colonisation but had benefits on inflammatory and immune markers, which might be related to some features of gastrointestinal tolerance.

Fecal calprotectin: cutoff values for identifying intestinal distress in preterm infants.

This study aimed to determine cutoff levels for fecal calprotectin as a marker of intestinal distress in preterm neonates. A total of 126 infants born at a median gestational age of 33 weeks (range 25.7–35 weeks) were enrolled. Samples (n = 312) were collected weekly from the end of the first week of life until the end of the first month and if any gastrointestinal event occurred. Receiver operating characteristic curves analysis gave cutoff values of 363 μg/g (sensitivity 0.65, specificity 0.82) and 636 μg/g (sensitivity 0.72, specificity 0.95) for the development of mild or severe enteropathy.

Faecal Calprotectin in Term and Preterm Neonates

Objectives: The aim of this review was to examine the characteristics of the faecal calprotectin assay in neonates and the evidence for its use as a noninvasive marker of intestinal illnesses during the neonatal period. Methods: Bibliographic searches were performed in the MEDLINE electronic database up to February 2010 looking for the following words (all fields): “infants” or “neonates” and “calprotectin.” Twenty studies, in which 1180 neonates were enrolled, were selected. Results: During the neonatal period, calprotectin levels are characterized by significantly higher values in both healthy full-term and preterm infants during their first year of life compared with reference values established for children and adults. No difference was observed according to gestational age or birth weight, whereas a higher faecal calprotectin level was detected during intestinal distress in neonates with either inflammatory or patent digestive alterations. Despite high interindividual variations, cutoff levels are proposed to identify infants with a high risk of intestinal illnesses. Conclusions: Compared with adults and children, healthy full-term and preterm neonates have high calprotectin levels. The measurement of calprotectin levels in faeces can be a promising noninvasive clinical screening test for intestinal distress in neonates.

Mise en place de la flore intestinale du nouveau-né

Resume Le microbiote intestinal est un ecosysteme extremement complexe, comportant environ 1014 micro-organismes recouvrant pres de 400 especes bacteriennes. C’est un element actif de la physiologie intestinale, avec des fonctions metaboliques, de flore de barriere et de stimulation du systeme immunitaire intestinal. La plupart des etudes de ce microbiote sont basees sur des techniques de culture, mais des techniques de biologie moleculaire permettent de completer ces donnees. La formation de cet ecosysteme debute tres rapidement apres la naissance. Le nouveau-ne, sterile a la naissance, se colonise avec une flore resultant du contact avec sa mere et son environnement. Si les facteurs d’implantation de la flore sont peu connus, de nombreux facteurs vont influencer l’etablissement de ce microbiote : mode d’accouchement, environnement, mode d’alimentation, âge gestationnel et antibiotherapie. Des donnees recentes font etat de modifications dans l’etablissement de cette flore, avec un retard d’implantation des bacteries enteriques d’origine maternelle, dues entre autres aux conditions d’hygiene strictes entourant les accouchements. Les consequences cliniques de ces modifications sont mal connues mais pourraient etre responsables d’une absence de flore de barriere ou d’une mauvaise stimulation du systeme immunitaire intestinal. La question de l’interet de la modulation de la flore du nouveau-ne par l’ajout dans les formules infantiles de probiotiques, prebiotiques, bacteries non viables et leurs metabolites, ou nucleotides est posee et discutee.

Clostridia in Premature Neonates' Gut: Incidence, Antibiotic Susceptibility, and Perinatal Determinants Influencing Colonization

Background Although premature neonates (PN) gut microbiota has been studied, data about gut clostridial colonization in PN are scarce. Few studies have reported clostridia colonization in PN whereas Bacteroides and bifidobacteria have been seldom isolated. Such aberrant gut microbiota has been suggested to be a risk factor for the development of intestinal infections. Besides, PN are often treated by broad spectrum antibiotics, but little is known about how antibiotics can influence clostridial colonization based on their susceptibility patterns. The aim of this study was to report the distribution of Clostridium species isolated in feces from PN and to determine their antimicrobial susceptibility patterns. Additionally, clostridial colonization perinatal determinants were analyzed. Results Of the 76 PN followed until hospital discharge in three French neonatal intensive care units (NICUs), 79% were colonized by clostridia. Clostridium sp. colonization, with a high diversity of species, increased throughout the hospitalization. Antibiotic courses had no effect on the clostridial colonization incidence although strains were found susceptible (except C. difficile) to anti-anaerobe molecules tested. However, levels of colonization were decreased by either antenatal or neonatal (during more than 10 days) antibiotic courses (p = 0.006 and p = 0.001, respectively). Besides, incidence of colonization was depending on the NICU (p = 0.048). Conclusion This study shows that clostridia are part of the PN gut microbiota. It provides for the first time information on the status of clostridia antimicrobial susceptibility in PN showing that strains were susceptible to most antibiotic molecules. Thus, the high prevalence of this genus is not linked to a high degree of resistance to antimicrobial agents or to the use of antibiotics in NICUs. The main perinatal determinant influencing PN clostridia colonization appears to be the NICU environment.

Intestinal permeability and fecal eosinophil-derived neurotoxin are the best diagnosis tools for digestive non-IgE-mediated cow’s milk allergy in toddlers

Abstract Background: Food allergy is a common problem in France involving 4%–6% of toddlers. As opposed to IgE-mediated cow’s milk allergy (CMA), delayed-onset CMA, mostly, non-IgE-mediated, remains difficult to diagnose in toddlers. Our study assessed the diagnostic performances of intestinal permeability and of fecal markers, in comparison with the standard allergic work-up in children referred for CMA diagnosis. Methods: Twenty-five consecutive children, mean age (standard deviation) 6.3 months (4.8) with digestive and/or extra-digestive manifestations suggesting CMA, were prospectively studied based on a standardized allergic work-up (specific cow’s protein IgE and IgG, skin prick test, atopy patch test and oral open cow’s milk challenge) and digestive work-up including fecal microbiota analysis, intestinal permeability determination (urinary lactitol/mannitol ratio) and fecal markers measurement, i.e., α1-antitrypsin, tumor necrosis factor-α, calprotectin, β-defensin2, secretory IgA and eosinophil-derived neurotoxin (EDN). Receiver operating characteristic (ROC) curves were calculated for all markers in order to define cut-off levels. Results: The cow’s milk challenge was positive in 11 children and negative in 14. The global test performances, i.e., the number of true positive+negative cases/the total number of cases, were 76% for intestinal permeability; 72% for fecal EDN; contrasting with atopy patch test, 68%; IgE, 60%; skin prick test, 55% and IgG, 52%. Conclusions: In this routine diagnosis allergy work-up for CMA in toddlers, the best efficacy was seen for intestinal permeability compared to IgE, IgG, skin prick test and atopy patch test. Moreover, fecal EDN in a single spot sample displayed a similar performance.

Time course of faecal calprotectin in preterm newborns during the first month of life.

1.Service de Néonatologie, APHP, Groupe Hospitalier Cochin-Saint Vincent de Paul, Paris, France 2.UFR de Médecine, Université Paris Descartes, Paris, France 3.Laboratoire de Microbiologie, UFR Pharmacie, Université Paris Descartes, Paris, France 4.Laboratoire de Coprologie, APHP, Groupe Hospitalier Pitié-Salpétrière, Paris, France 5.Laboratoire de Parasitologie, UFR Pharmacie, Université Paris Descartes, Paris, France

Diversity of gut Bifidobacterium species is not altered between allergic and non-allergic French infants.

Some clinical studies have suggested a relationship between allergic diseases and gut microbiota. We aimed to study bifidobacterial colonization at species and strain levels in ten allergic French infants included at their first clinical consultation and 20 controls matching for age at sampling, mode of delivery, per partum antibiotics, type of feeding and antibiotics in the first weeks of life. The faecal microbiota was analyzed by culture methods and TTGE. Bifidobacterial species and strains were identified using multiplex PCR and Box-PCR fingerprinting. No differences were observed between groups in the number of colonized infants or in the levels of colonization by the main aerobic and anaerobic genera. All infants were colonized with high levels of Bifidobacterium except for one in each group. One to 5 Bifidobacterium species and 1 to 7 strains were observed per subject independently of allergic status and age at sampling. Our study showed the infants to be colonized by several species and strains, including several strains from the same species. This diversity in Bifidobacterium colonization was not related with the allergic status and showed that the link between Bifidobacterium colonization and allergic diseases is complex and cannot be restricted to the role attributed to Bifidobacterium species.

Fecal Expression of Human β-Defensin-2 following Birth

Background: Newborns display high intestinal permeability and a naive adaptive immune system, but infections are rare, indicating strong innate defense mechanisms. Objective: To measure the kinetics of fecal β-defensin-2 (HBD2), an inducible endogenous antimicrobial peptide produced by intestinal epithelial cells, in full-term and preterm infants. Methods: As a first step of this bicentric study, we enrolled 30 healthy full-term infants and 20 healthy preterm infants, with fecal samples collected at days 3, 7 12 and 30 in full-term infants and at days 15, 30 and 60 in preterm infants. As a second step, we enrolled 10 preterm infants with intestinal distress, either necrotizing enterocolitis (NEC) Bell’s stage III (n = 3) or isolated rectal bleeding (n = 7) and 20 controls, cross-matched for gestational age and age at sampling. Results: HBD2 decreased significantly from day 3 to day 7 (227 ng/g; 14–440 vs. 117 ng/g; 30–470, p = 0.01) then moderately until day 30 (84 ng/g; 10–500) in healthy full-term infants. Healthy preterm infants showed similar high levels between days 15 and 60 (82 ng/g; 30–154 and 85 ng/g; 26–390, respectively). No significant variation of fecal HBD2 levels was observed between infants with clinical features of intestinal distress (77 ng/g, 2–1,271) and cross-matched controls (56 ng/g, 31–164). However, 2/3 infants with NEC and 1/7 infants with isolated rectal bleeding had HBD2 levels above the maximal level observed in controls. Conclusions: The kinetics of fecal HBD2 in the neonatal period indicate that this inducible defensin can be detected at high level in the feces of full-term and preterm infants, independently of gestational age or mode of feeding. The potential role of fecal HBD2 in detecting NEC is suggested.