Eugenia Bruzzese

Intestinal inflammation is a frequent feature of cystic fibrosis and is reduced by probiotic administration

Aims : To assess the incidence of intestinal inflammation in children with cystic fibrosis and to investigate whether probiotics decrease it.

A formula containing galacto- and fructo-oligosaccharides prevents intestinal and extra-intestinal infections: an observational study.

BACKGROUND & AIM The addition of prebiotics to infant formula modifies the composition of intestinal microflora. Aim of the study was to test the hypothesis that prebiotics reduce the incidence of intestinal and respiratory infections in healthy infants. METHODS A prospective, randomized, placebo-controlled, open trial was performed. Healthy infants were enrolled and randomized to a formula additioned with a mixture of galacto- and fructo-oligosaccharides or to a control formula. The incidence of intestinal and respiratory tract infections and the anthropometric measures were monitored for 12 months. RESULTS Three hundred and forty two infants (mean age 53.7+/-32.1 days) were enrolled. The incidence of gastroenteritis was lower in the supplemented group than in the controls (0.12+/-0.04 vs. 0.29+/-0.05 episodes/child/12 months; p=0.015). The number of children with more than 3 episodes tended to be lower in prebiotic group (17/60 vs. 29/65; p=0.06). The number of children with multiple antibiotic courses/year was lower in children receiving prebiotics (24/60 vs. 43/65; p=0.004). A transient increase in body weight was observed in children on prebiotics compared to controls during the first 6 months of follow-up. CONCLUSIONS Prebiotic administration reduce intestinal and, possibly, respiratory infections in healthy infants during the first year of age.

Lactoferrin Induces Concentration-Dependent Functional Modulation of Intestinal Proliferation and Differentiation

Human milk stimulates intestinal development through the effects of various moieties. Lactoferrin (LF) is a glycoprotein of human milk whose concentration is highest in colostrum decreasing in mature milk. LF promotes enterocyte growth in intestinal cell lines. We tested the hypothesis that LF induces a distinct effect on enterocyte proliferation and differentiation, depending on its concentration. We examined the dose-related effects by human-native LF (N-LF) in Caco-2 (human colon adenocarcinoma) cells. At high concentrations, N-LF stimulated cell proliferation in immature Caco-2 cells, as judged by 3H-thymidine incorporation. In contrast, sucrase and lactase activities were increased at low but not high LF concentrations and their mRNA were also increased, indicating a transcriptional effect. Because iron binds specific LF sites, we compared the potency of N-LF and iron-saturated LF (I-LF) and found the native form more potent. Finally, we tested the effects by bovine LF (bLF) in the same system and found the latter more potent than the human isoform in inducing cell growth and lactase expression. These results suggest that LF directly induces enterocyte growth and proliferation, depending on its concentration, thereby regulating the earlyx postnatal intestinal development. bLF could be added to infant formula as a growth factor in selected intestinal diseases.

Disrupted Intestinal Microbiota and Intestinal Inflammation in Children with Cystic Fibrosis and Its Restoration with Lactobacillus GG: A Randomised Clinical Trial

Background & Aims Intestinal inflammation is a hallmark of cystic fibrosis (CF). Administration of probiotics can reduce intestinal inflammation and the incidence of pulmonary exacerbations. We investigated the composition of intestinal microbiota in children with CF and analyzed its relationship with intestinal inflammation. We also investigated the microflora structure before and after Lactobacillus GG (LGG) administration in children with CF with and without antibiotic treatment. Methods The intestinal microbiota were analyzed by denaturing gradient gel electrophoresis (DGGE), real-time polymerase chain reaction (RT-PCR), and fluorescence in situ hybridization (FISH). Intestinal inflammation was assessed by measuring fecal calprotectin (CLP) and rectal nitric oxide (rNO) production in children with CF as compared with healthy controls. We then carried out a small double-blind randomized clinical trial with LGG. Results Twenty-two children with CF children were enrolled in the study (median age, 7 years; range, 2–9 years). Fecal CLP and rNO levels were higher in children with CF than in healthy controls (184±146 µg/g vs. 52±46 µg/g; 18±15 vs. 2.6±1.2 µmol/L NO2 −, respectively; P<0.01). Compared with healthy controls, children with CF had significantly different intestinal microbial core structures. The levels of Eubacterium rectale, Bacteroides uniformis, Bacteroides vulgatus, Bifidobacterium adolescentis, Bifidobacterium catenulatum, and Faecalibacterium prausnitzii were reduced in children with CF. A similar but more extreme pattern was observed in children with CF who were taking antibiotics. LGG administration reduced fecal CLP and partially restored intestinal microbiota. There was a significant correlation between reduced microbial richness and intestinal inflammation. Conclusions CF causes qualitative and quantitative changes in intestinal microbiota, which may represent a novel therapeutic target in the treatment of CF. Administration of probiotics restored gut microbiota, supporting the efficacy of probiotics in reducing intestinal inflammation and pulmonary exacerbations. Trial Registration ClinicalTrials.gov NCT 01961661

Adherence to antiretroviral therapy and its determinants in children with human immunodeficiency virus infection: a multicentre, national study

Aim: To investigate rates and determinants of adherence to antiretroviral therapy in Italian children infected with the human immunodeficiency virus (HIV). Methods: An observational, cross‐sectional multicentre study was performed through a structured interview with the caregivers of HIV‐infected children. The interview included quantitative information on adherence in the 4 d before interview. Sociodemographic, clinical and psychosocial characteristics of children were recorded. Results: 129 children (median age 96 mo) were enrolled, of whom 94 were on highly active antiretroviral therapy (HAART). Twenty‐one (16%) omitted more than 5% of total doses in 4 d and were considered non‐adherent. However, only 11% of caregivers reported that therapy had been administered at the correct times. No significant difference was found between age and the stage of HIV infection. Children aware of their HIV status were less adherent. Individual drugs showed a broad adherence pattern and children who received HAART were more adherent. Children receiving therapy from foster parents were more adherent than those receiving drugs from biological parents or relatives.

Impact of prebiotics on human health

It is becoming clear that intestinal microflora plays an important role in the development of local and systemic immune response. Nutritional ingredients have been added to infant formula in an attempt to make its composition similar to that of human milk. The effects of these modifications have been observed in the composition of intestinal microflora. Prebiotics are non-digestible foods able to selectively stimulate the growth/activity of a limited number of colonic bacteria. A mixture of galacto-oligosaccharides and fructo-oligosaccharides (GOS/FOS) induces an increase in Bifidobacteria, similar to that of breast-fed infants. What is less clear is whether the modifications of intestinal microflora obtained by functional foods are associated with clinically measurable effects. Preliminary indirect data suggest that increasing the load of Bifidobacteria and Lactobacilli may protect from infections and allergies and this effect may persists beyond infancy. The emerging concept is that early nutritional intervention may be effective in modifying the intestinal microflora composition in a phase in which microbiological imprinting may drive immunological imprinting thereby producing clinical effects. Further investigations and well designed randomised clinical trials are needed to demonstrate the potential beneficial effects and to exclude the potential side effects.

Smectite in the treatment of acute diarrhea: a nationwide randomized controlled study of the Italian Society of Pediatric Gastroenterology and Hepatology (SIGEP) in collaboration with primary care pediatricians. SIGEP Study Group for Smectite in Acute Diarrhea.

Background Childhood gastroenteritis is associated with considerable health costs. The natural clay dioctahedral smectite increases intestinal barrier function and is effective against infectious diarrhea in children in developing countries. The purpose of this work was to investigate the efficacy of smectite in Italian children with acute diarrhea of mild to moderate severity. Methods A national, prospective, randomized, case-controlled study was performed in collaboration with primary care pediatricians. Children seen by pediatricians for acute gastroenteritis were treated with oral rehydration solution (ORS) alone or ORS with smectite. Parents returned a form in which total duration of diarrhea, incidence of vomiting and fever, persistence of diarrhea for more than 7 days and hospital admissions were recorded. Results Eight hundred four children with acute diarrhea were randomly assigned to treated or control groups. Administration of smectite was associated with significant reduction of the duration of diarrhea, as judged by stool frequency and consistency. The incidence and duration of vomiting and fever were not different. Diarrhea lasted more than 7 days in 10% of treated and in 18% of control children (P < 0.01). Hospital admission was necessary in seven treated and six control children. No side effects were observed. Conclusions Smectite reduces the duration of diarrhea and prevents a prolonged course. It may therefore consistently reduce the costs of gastroenteritis.

Early treatment with ursodeoxycholic acid for cholestasis in children on parenteral nutrition because of primary intestinal failure.

There is conflicting evidence as to whether ursodeoxycholic acid (UDCA) reduces the incidence of parenteral nutrition‐associated cholestasis.

Enterotoxic effect of the vacuolating toxin produced by Helicobacter pylori in Caco-2 cells

Preliminary clinical evidence suggests that Helicobacter pylori may be associated with diarrhea through its vacuolating toxin (VacA). To establish whether VacA induces intestinal secretion, epithelial damage, or both, purified pH-activated VacA was added to Caco-2 cell monolayers mounted in Ussing chambers, and electrical parameters were monitored. Mucosal addition of VacA induced an increase in short circuit current, consistent with enterotoxic effect. The effect was time- and dose-dependent and saturable. It was not found if the toxin was not pH-activated, added to the serosal side, or preheated. In cells preloaded with the Ca2+ buffering compound BAPTA/AM or with the Cl- channel inhibitor 5-nitro-2-3-(3-phenylpropylamino)benzoic acid, short circuit current did not change, indicating that VacA induces activation of Ca2+-dependent Cl- channels. VacA did not show cytopathic effects, as judged by tissue resistance. These results support the hypothesis that H. pylori may be associated with diarrhea through production of VacA.

Management of gastrointestinal disorders in children with HIV infection.

A double scenario characterizes the epidemiology of HIV infection in children. In countries where highly active antiretroviral therapy (HAART) is available, the pattern of HIV infection is evolving into that of a chronic disease, for which control strictly depends on patients’ adherence to treatment. In developing countries with no or limited access to HAART, AIDS is rapidly expanding and is loaded with a high fatality ratio, due to the combined effects of malnutrition and opportunistic infections.The digestive tract is a target of the disease in both settings. Opportunistic infections play a major role in children with severe immune impairment, with Cryptosporidium parvum being the leading agent of severe diarrhea. Several therapeutic approaches are effective in reducing fecal output, but the eradication of the parasite is rarely obtained. Other opportunistic infections may induce severe and protracted diarrhea, including atypical mycobacteria and cytomegalovirus. Diagnosis of diarrhea should be individually tailored based on presenting symptoms and risk factors. A stepwise approach is effective in limiting patient discomfort and minimizing the costs of investigations, starting with microbiologic investigation and proceeding with endoscopy and histology. Aggressive treatment of infectious diarrhea is required in severely immunocompromised children. However, antiretroviral therapy prevents the development of severe cryptosporidiosis.The liver and pancreas are also target organs in HIV infection, although functional failure is rare. The digestive-absorptive functions are impaired, with steatorrhea, nutrient malabsorption, and increased permeability occurring in 20–70% of children. Intestinal dysfunction contributes to growth failure and further immune derangement, leading to wasting, the terminal stage of AIDS. Nutritional management is crucial in HIV-infected children and is based on aggressive nutritional rehabilitation through enteral or parenteral routes and micronutrient supplementation.HIV may play a direct enteropathogenic role and is implicated in both diarrhea and intestinal dysfunction. This explains the efficacy of antiretroviral therapy in inducing remission of diarrhea and restoring intestinal function.Gastrointestinal side effects of antiretroviral drugs are increasingly observed; they are often mild and transient. Severe reactions are rare but require the withdrawal of drugs.In conclusion, severe enteric infections and intestinal dysfunction characterize the intestinal involvement of HIV infection. This is more common in, but not limited to, children who do not receive effective antiretroviral therapy. Diagnostic approaches include microbiologic and morphologic examinations and assessment of digestive processes, but immunologic and virologic data should be also carefully considered. Treatment is based upon specific anti-infectious drugs, antiretroviral therapy, and nutritional rehabilitation.