Although the health-promoting roles of bifidobacteria are widely accepted, the diversity of bifidobacteria among the human intestinal microbiota is still poorly understood. We performed a census of bifidobacterial populations from human intestinal mucosal and fecal samples by plating them on selective medium, coupled with molecular analysis of selected rRNA gene sequences (16S rRNA gene and internally transcribed spacer [ITS] 16S-23S spacer sequences) of isolated colonies. A total of 900 isolates were collected, of which 704 were shown to belong to bifidobacteria. Analyses showed that the culturable bifidobacterial population from intestinal and fecal samples include six main phylogenetic taxa, i.e., Bifidobacterium longum , Bifidobacterium pseudocatenulatum , Bifidobacterium adolescentis , Bifidobacterium pseudolongum , Bifidobacterium breve , and Bifidobacterium bifidum , and two species mostly detected in fecal samples, i.e., Bifidobacterium dentium and Bifidobacterium animalis subp. lactis . Analysis of bifidobacterial distribution based on age of the subject revealed that certain identified bifidobacterial species were exclusively present in the adult human gut microbiota whereas others were found to be widely distributed. We encountered significant intersubject variability and composition differences between fecal and mucosa-adherent bifidobacterial communities. In contrast, a modest diversification of bifidobacterial populations was noticed between different intestinal regions within the same individual (intrasubject variability). Notably, a small number of bifidobacterial isolates were shown to display a wide ecological distribution, thus suggesting that they possess a broad colonization capacity.

Vitamin D plays a pivotal role in the regulation of calcium-phosphorus metabolism, particularly during pediatric age when nutritional rickets and impaired bone mass acquisition may occur. Besides its historical skeletal functions, in the last years it has been demonstrated that vitamin D directly or indirectly regulates up to 1250 genes, playing so-called extraskeletal actions. Indeed, recent data suggest a possible role of vitamin D in the pathogenesis of several pathological conditions, including infectious, allergic and autoimmune diseases. Thus, vitamin D deficiency may affect not only musculoskeletal health but also a potentially wide range of acute and chronic conditions. At present, the prevalence of vitamin D deficiency is high in Italian children and adolescents, and national recommendations on vitamin D supplementation during pediatric age are lacking. An expert panel of the Italian Society of Preventive and Social Pediatrics reviewed available literature focusing on randomized controlled trials of vitamin D supplementation to provide a practical approach to vitamin D supplementation for infants, children and adolescents.

Helicobacter pylori infection is mainly acquired in childhood and may predispose to peptic ulcer or gastric cancer later in life.1 Non-invasive diagnostic tools are particularly useful in children as screening tests and for epidemiological studies, but their accuracy has to be tested against that of invasive tests in symptomatic patients before they are used in any particular population. Of the non-invasive tests now available, serological testing is not accurate in young patients and the 13C urea breath test is expensive. In 1998 an enzyme linked immunoassay (ELISA) (Premier-Platinum-HpSA, Meridian Diagnostics, Cincinnati, OH, USA) was approved by the Food and Drug Administration for both diagnosis in adult symptomatic patients, and monitoring the response to treatment. It is now commercially available, but its correlation with gastric infection has not been assessed in children. We evaluated its diagnostic accuracy against invasive tests in children undergoing endoscopy for clinical evaluation, and we determined the cut off values for the paediatric population. View this table: Test performance calculated according to different reading techniques (at 450 …

Summary: Background : Infliximab is an effective therapy in adult patients with refractory and fistulizing Crohn's disease. Experience in children is still limited.Aim : To evaluate the experience in 22 children and adolescents treated with infliximab with refractory and/or fistulizing Crohn's disease, and to compare duration of response in children between early Crohn's disease and late Crohn's disease.Methods : The experience in 22 children and adolescents treated with a total of 73 infusions was evaluated retrospectively. Treatment indication was refractory Crohn's disease in 9/22 patients, fistulizing Crohn's disease in 7/22 patients and both these conditions in 6/22. All patients with refractory Crohn's disease had late Crohn's disease (> 1 year), whereas 6/13 patients with fistulas had early disease (< 1 year).Results : Mean Paediatric Crohn's Disease Activity Index (PCDAI) decreased from 41.2 to 16.2 at 4 weeks (P < 0.01), and to 15.4 at 18 weeks (P < 0.01). Mean PCDAI at 18 weeks in children with early Crohn's disease and late Crohn's disease was 5.5 and 18.1, respectively (P < 0.05). Complete closure of fistulas was obtained in 5/6 children with early Crohn's disease and in 2/7 children with late Crohn's disease. Immediate adverse reactions were observed in two children.Conclusions : Infliximab is a highly effective treatment in children and adolescents with both severe refractory or fistulizing Crohn's disease. Children with early Crohn's disease have a higher chance of prolonged response to infliximab than children with late Crohn's disease.