Potential role of the intestinal microbiota of the mother in neonatal immune education.

Mucosal dendritic cells are at the heart of decision-making processes that dictate immune reactivity to intestinal microbes. They ensure tolerance to commensal bacteria and a vigorous immune response to pathogens. It has recently been demonstrated that the former involves a limited migration of bacterially loaded dendritic cells from the Peyer's patches to the mesenteric lymph nodes.

The inflammatory status of the elderly: the intestinal contribution.

A common finding in the elderly population is a chronic subclinical inflammatory status that coexists with immune dysfunction. These interconnected processes are of sufficient magnitude to impact health and survival time. In this review we discuss the different signals that may stimulate the inflammatory process in the aging population as well as the molecular and cellular components that can participate in the initiation, the modulation or termination of the said process.

CD14: a soluble pattern recognition receptor in milk.

An innate immune system capable of distinguishing among self, non-self, and danger is a prerequisite for health. Upon antigenic challenge, pattern recognition receptors (PRRs), such as the Toll-like receptor (TLR) family of proteins, enable this system to recognize and interact with a number of microbial components and endogenous host proteins. In the healthy host, such interactions culminate in tolerance to self-antigen, dietary antigen, and commensal microorganisms but in protection against pathogenic attack.

Bacterial imprinting of the neonatal immune system: lessons from maternal cells?

Objective: We examined the presence of a natural bacterial inoculum in breast milk and its intracellular transport from the maternal intestine to the breast through the circulation.

Methods: Breast milk and peripheral blood were collected aseptically from healthy donors at various times after delivery, and the presence of viable bacteria was determined through plating. Temporal temperature gradient gel electrophoresis was used to examine the bacterial ribosomal DNA content in milk cells, maternal peripheral blood mononuclear cells, and feces and in corresponding infant feces.

Osteoprotegerin in human milk: a potential role in the regulation of bone metabolism and immune development.

Osteoprotegerin (OPG) is a member of the tumor necrosis factor superfamily. It is a soluble "decoy" receptor for tumor necrosis factor-related apoptosis-inducing ligand and ligand of the receptor activator of NF-kappaB. As such, OPG inhibits osteoclast activity and regulates the immune system.

Lipoteichoic acids from Lactobacillus johnsonii strain La1 and Lactobacillus acidophilus strain La10 antagonize the responsiveness of human intestinal epithelial HT29 cells to lipopolysaccharide and gram-negative bacteria.

Intestinal epithelial cells (IECs) respond to lipopolysaccharide (LPS) from gram-negative bacteria in the presence of the soluble form of CD14 (sCD14), a major endotoxin receptor. Since sCD14 is also known to interact with gram-positive bacteria and their components, we looked at whether sCD14 could mediate their effects on human IECs. To this end, we examined the production of proinflammatory cytokines following exposure of the IECs to specific gram-positive bacteria or their lipoteichoic acids (LTAs) in the absence and presence of human milk as a source of sCD14.

The intestinal mucosa as a target for dietary polyunsaturated fatty acids.

Several studies have reported beneficial effects of dietary polyunsaturated fatty acids (PUFA) on various aspects of both human and animal health, and particular reference has been made to their effects on systemic immune responses. Both immune stimulation and immune suppression have been reported, with the outcome dependent on the type of PUFA, the target cell, as well as the immune competence of the cells before exposure. The systemic and the mucosal immune systems are discrete entities, which have evolved specific approaches in the defense of the host.

Soluble CD14 in human breast milk and its role in innate immune responses.

Immune factors secreted in milk are important for health in the neonatal gut. We have detected the bacterial pattern recognition receptor, soluble CD14 (sCD14) in human breast milk at different times during lactation. The molecule occurs in a single form in milk, in contrast to human serum, in which there are two isoforms.

Short-term fish oil supplementation improved innate immunity, but increased ex vivo oxidation of LDL in man--a pilot study.

Background: Fish and fish oils are rich in the two long-chain polyunsaturated fatty acids (LCPUFAs) eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3). The n-3 LCPUFAs have been reported to have beneficial effects on cardiovascular functions, but their role in relation to immune functions is still controversial.

Aim Of The Study: The objectives of this study were to determine the effects of supplementation with fish oil on immune cell functions in human subjects.

Remission induced by a new specific oral polymeric diet in children with Crohn's disease.

We have been able to show that CT3211 is an effective oral treatment in children with active Crohn's disease. It was well tolerated, and there were minimal side effects. At the mucosal site of disease there was macroscopic and histological improvement, together with evidence of downregulation of the pro-inflammatory cytokines IL-1 beta, IL-8, and IFN-gamma.

Innate recognition of bacteria in human milk is mediated by a milk-derived highly expressed pattern recognition receptor, soluble CD14.

Little is known about innate immunity to bacteria after birth in the hitherto sterile fetal intestine. Breast-feeding has long been associated with a lower incidence of gastrointestinal infections and inflammatory and allergic diseases. We found in human breast milk a 48-kD polypeptide, which we confirmed by mass spectrometry and sequencing to be a soluble form of the bacterial pattern recognition receptor CD14 (sCD14).

Mucosal healing and a fall in mucosal pro-inflammatory cytokine mRNA induced by a specific oral polymeric diet in paediatric Crohn's disease.

Background: Although enteral nutrition is a recognized form of treatment for intestinal Crohn's disease, there are persisting problems with feed palatability and only limited data as to its mode of action.

Aim: To assess the effects of a specific oral polymeric diet (CT3211; Nestle, Vevey, Switzerland), which is rich in transforming growth factor beta2, on the mucosal inflammatory process.

Methods: Twenty-nine consecutive children with active intestinal Crohn's disease were treated with CT3211 as the sole source of nutrition for 8 weeks.

Bioactive molecules in milk and their role in health and disease: the role of transforming growth factor-beta.

Human breast milk is rich in nutrients, hormones, growth factors and immunoactive molecules, which influence the growth, development and immune status of the newborn infant. Although several of these factors are also present in bovine milk, the greater susceptibility of the formula-fed infant to infection and disease and the development of allergy is often attributed to the reduced level of protective factors in milk formulas. Nevertheless, modifying manufacturing processes may preserve the biological activity of some bioactive molecules in end products.

Modulation of nonspecific mechanisms of defense by lactic acid bacteria: effective dose.

The purpose of this study was to determine the effect of a fermented milk product containing Lactobacillus johnsonii La1 (formerly known as Lactobacillus acidophilus La1) on the phagocytic activity of peripheral blood leukocytes in healthy adult volunteers. Furthermore, we sought to define the effective doses of the bacteria, examine the effect on respiratory burst activity, and, finally, examine the contribution made by the starter culture to the biological effects. Volunteers were randomly distributed among three groups; each subject received one pot (150 ml) of fermented milk each day for 3 wk.

Immune modulation of blood leukocytes in humans by lactic acid bacteria: criteria for strain selection.

Lactic acid bacteria in food can transiently colonize the intestine and exert beneficial effects (probiotic). Survival during intestinal transit or adhesion to epithelium or both seem to be important for modifying the host's immune reactivity. Because Lactobacillus acidophilus strain La1 is adherent to enterocytes in vitro, we hypothesize that contact with immune cells may occur in vivo.

Immunomodulation of human blood cells following the ingestion of lactic acid bacteria.

Because of the lack of data that convincingly show immunomodulatory properties of lactic acid bacteria in humans, a study was performed in which healthy volunteers were divided into two groups and given a fermented milk product supplemented with Lactobacillus acidophilus strain La1 or Bifidobacterium bifidum strain Bb 12 for 3 wk. Blood was sampled throughout the study to assess changes in lymphocyte subsets or leukocyte phagocytic activity following consumption of the fermented products. No modifications of lymphocyte subpopulations were detected.

Expression of MHC antigens by intestinal epithelial cells. Effect of transforming growth factor-beta 2 (TGF-beta 2).

The effect of interferon-gamma (IFN-gamma) and TGF-beta 2 on expression of MHC antigens by the human intestinal epithelial cell line HT-29 was examined by immunohistochemistry and flow cytometry. Untreated HT-29 cells constitutively expressed HLA-ABC but little HLA-DR. Expression of both molecules was increased by IFN-gamma (100 U/ml, 24 h).

Polymeric nutrition as the primary therapy in children with small bowel Crohn's disease.

Background: Recent studies in adults have shown that polymeric (whole protein) diets are as effective as semi-elemental and elemental formulae for the induction of remission in small bowel Crohn's disease. Whole protein diets are more palatable and cheaper. There have been no studies confirming efficacy in children.