Effect of maternal supplement beverage with and without probiotics during pregnancy and lactation on maternal and infant health: a randomized controlled trial in the Philippines.

BACKGROUND: Adequate nutrition is essential during pregnancy and lactation to provide sufficient energy and nutrients to meet the nutritional requirements of the mother, fetus and infant. The primary objective of this study was to assess the effect of a maternal nutritional supplement enriched with probiotics during pregnancy and early lactation on the incidence of infant diarrhea. METHODS: Healthy, pregnant (24-28 weeks gestation) women were randomized 1:1:1 to receive either no supplement or two servings per day of an oral supplement (140 kcal/serving) providing 7.9 g protein, multivitamin/minerals, and enriched or not with the probiotics Lactobacillus rhamnosus and Bifidobacterium lactis, from the third trimester of pregnancy until at least 2 months post-delivery. Incidence of infant diarrhea until 12 months post-delivery was analyzed by Poisson regression. The effect on maternal health, fetal growth, and infant growth and morbidity were also evaluated and analyzed by ANOVA. RESULTS: A total of 208 mother/infant pairs were included in the analysis. No significant difference in the incidence of infant diarrhea was observed between the three study groups. The mean maternal weight gains at delivery were similar among groups, despite an increase in caloric intake in the supplemented groups. No statistically significant differences between groups were observed in incidence of pregnancy-related or fetal adverse outcomes. Mean weight-, length-, BMI- and head circumference-for-age z-scores were below the WHO median value for all groups. Post-hoc analysis to compare the effect of the combined supplement groups versus the no supplement group on infant growth parameters showed, at 12 months, that the combined supplemented group had gained statistically significant more weight (8.97 vs. 8.61 kg, p = 0.001) and height (74.2 vs. 73.4 cm, p = 0.031), and had a higher weight-for-age z-score (- 0.62 vs. -0.88, p = 0.045) than the no supplement group. CONCLUSIONS: Maternal nutritional supplement with or without probiotics given during late pregnancy and early lactation was well tolerated and safe. Even though no difference in incidence of infant diarrhea was observed between the three groups, the analysis of the combined supplemented groups showed beneficial effects of maternal supplementation on infant weight and length gains at 12 months. TRIAL REGISTRATION: ClinicalTrial.gov: NCT01073033 . Registered 17.02.2010.

Influenza vaccine response in community-dwelling German prefrail and frail individuals.

BACKGROUND: The age-related dysregulation of the immune system in older persons results in reduced responses to vaccination and greater susceptibility to infection, especially in frail individuals who suffer the greatest of morbidity and mortality due to infection. Recently, significantly reduced anti-influenza antibody titers and increased rates of influenza infection after vaccination were reported in community-dwelling American frail older adults. The aim of our study was to further assess the relative impact of frailty and of each individual Fried frailty criterion on influenza vaccine response. Prefrail and frail community-dwelling German persons aged ≥70 years were recruited for a nutritional randomized double-blind placebo-controlled clinical trial conducted during the 2014-2015 influenza season. Herein, we present a sub-analysis study of the placebo group to compare 76 prefrail and frail participants. RESULTS: Previous seasonal influenza vaccination rate was relatively high (77.6%) in the 76 volunteers aged from 70 to 93 years. Of these participants, 65.8% were diagnosed as prefrail and 34.2% as frail according to the Fried frailty criteria. In both prefrail and frail groups, elevated levels of pre-vaccination seroprotection were observed to all vaccine strains (H1N1: 54% and 32%, H3N2: 60% and 72%, B: 10% and 16%). Post-vaccination, similar increases in haemagglutination-inhibiting antibody titers were observed for the three vaccine strains in both prefrail and frail groups. No significant difference in geometric mean titer (GMT) ratios and in rates of seroconversion or seroprotection were observed between prefrail and frail groups. Regarding the five Fried frailty criteria, only participants with low physical activity had significantly lower GMT to the strains H3N2 (55.4 vs 103.7, p = 0.001) and B (13.9 vs 20.0, p = 0.06), as compared to those having normal physical activity. CONCLUSIONS: Influenza vaccine response was not significantly affected by the frail phenotype, as defined by Fried frailty criteria, in community-dwelling German individuals. However, low physical activity may be a relevant predictor of lower serological response in vaccinated older individuals. TRIAL REGISTRATION: Clinicaltrials.gov NCT02262091 (October 8, 2013).

Metabolic phenotyping of an adoptive transfer mouse model of experimental colitis and impact of dietary fish oil intake.

Inflammatory bowel diseases are acute and chronic disabling inflammatory disorders with multiple complex etiologies that are not well-defined. Chronic intestinal inflammation has been linked to an energy-deficient state of gut epithelium with alterations in oxidative metabolism. Plasma-, urine-, stool-, and liver-specific metabonomic analyses are reported in a naïve T cell adoptive transfer (AT) experimental model of colitis, which evaluated the impact of long-chain n-3 polyunsaturated fatty acid (PUFA)-enriched diet. Metabolic profiles of AT animals and their controls under chow diet or fish oil supplementation were compared to describe the (i) consequences of inflammatory processes and (ii) the differential impact of n-3 fatty acids. Inflammation was associated with higher glycoprotein levels (related to acute-phase response) and remodeling of PUFAs. Low triglyceride levels and enhanced PUFA levels in the liver suggest activation of lipolytic pathways that could lead to the observed increase of phospholipids in the liver (including plasmalogens and sphingomyelins). In parallel, the increase in stool excretion of most amino acids may indicate a protein-losing enteropathy. Fecal content of glutamine was lower in AT mice, a feature exacerbated under fish oil intervention that may reflect a functional relationship between intestinal inflammatory status and glutamine metabolism. The decrease in Krebs cycle intermediates in urine (succinate, α-ketoglutarate) also suggests a reduction in the glutaminolytic pathway at a systemic level. Our data indicate that inflammatory status is related to this overall loss of energy homeostasis.

Challenges in IBD Research 2024: Environmental Triggers.

Environmental factors play an important role in inflammatory bowel diseases (IBD; Crohn's disease, [CD], ulcerative colitis [UC]). As part of the Crohn's & Colitis Challenges 2024 agenda, the Environmental Triggers workgroup summarized the progress made in the field of environmental impact on IBD since the last Challenges cycle in this document. The workgroup identified 4 unmet gaps in this content area pertaining to 4 broad categories: (1) Epidemiology; (2) Exposomics and environmental measurement; (3) Biologic mechanisms; and (4) Interventions and Implementation. Within epidemiology, the biggest unmet gaps were in the study of environmental factors in understudied populations including racial and ethnic minority groups and in populations witnessing rapid rise in disease incidence globally. The workgroup also identified a lack of robust knowledge of how environmental factors may impact difference stages of the disease and for different disease-related end points. Leveraging existing cohorts and targeted new prospective studies were felt to be an important need for the field. The workgroup identified the limitations of traditional questionnaire-based assessment of environmental exposure and placed high priority on the identification of measurable biomarkers that can quantify cross-sectional and longitudinal environmental exposure. This would, in turn, allow for identifying the biologic mechanisms of influence of environmental factors on IBD and understand the heterogeneity in effect of such influences. Finally, the working group emphasized the importance of generating high-quality data on effective environmental modification on an individual and societal level, and the importance of scalable and sustainable methods to deliver such changes.

Environmental factors are important in inflammatory bowel diseases. It is a high priority to identify environmental factors impacting different disease stages and in different populations, develop biomarkers for such exposures, and generate evidence for modifying them to improve outcomes.

The role of secretory immunoglobulin A in the natural sensing of commensal bacteria by mouse Peyer's patch dendritic cells.

The mammalian gastrointestinal (GI) tract harbors a diverse population of commensal species collectively known as the microbiota, which interact continuously with the host. From very early in life, secretory IgA (SIgA) is found in association with intestinal bacteria. It is considered that this helps to ensure self-limiting growth of the microbiota and hence participates in symbiosis. However, the importance of this association in contributing to the mechanisms ensuring natural host-microorganism communication is in need of further investigation. In the present work, we examined the possible role of SIgA in the transport of commensal bacteria across the GI epithelium. Using an intestinal loop mouse model and fluorescently labeled bacteria, we found that entry of commensal bacteria in Peyer's patches (PP) via the M cell pathway was mediated by their association with SIgA. Preassociation of bacteria with nonspecific SIgA increased their dynamics of entry and restored the reduced transport observed in germ-free mice known to have a marked reduction in intestinal SIgA production. Selective SIgA-mediated targeting of bacteria is restricted to the tolerogenic CD11c(+)CD11b(+)CD8(-) dendritic cell subset located in the subepithelial dome region of PPs, confirming that the host is not ignorant of its resident commensals. In conclusion, our work supports the concept that SIgA-mediated monitoring of commensal bacteria targeting dendritic cells in the subepithelial dome region of PPs represents a mechanism whereby the host mucosal immune system controls the continuous dialogue between the host and commensal bacteria.

Time-resolved quantitative proteome analysis of in vivo intestinal development.

Postnatal intestinal development is a very dynamic process characterized by substantial morphological changes that coincide with functional adaption to the nutritional change from a diet rich in fat (milk) to a diet rich in carbohydrates on from weaning. Time-resolved studies of intestinal development have so far been limited to investigation at the transcription level or to single or few proteins at a time. In the present study, we elucidate proteomic changes of primary intestinal epithelial cells from jejunum during early suckling (1-7 days of age), middle suckling (7-14 days), and weaning period (14-35 days) in mice, using a label-free proteomics approach. We show differential expression of 520 proteins during intestinal development and a pronounced change of the proteome during the middle suckling period and weaning. Proteins involved in several metabolic processes were found differentially expressed along the development. The temporal expression profiles of enzymes of the glycolysis were found to correlate with the increase in carbohydrate uptake at weaning, whereas the abundance changes of proteins involved in fatty acid metabolism as well as lactose metabolism indicated a nondiet driven preparation for the nutritional change at weaning. Further, we report the developmental abundance changes of proteins playing a vital role in the neonatal acquisition of passive immunity. In addition, different isoforms of several proteins were quantified, which may contribute to a better understanding of the roles of the specific isoforms in the small intestine. In summary, we provide a first, time-resolved proteome profile of intestinal epithelial cells along postnatal intestinal development.

Effects of increase in fish oil intake on intestinal eicosanoids and inflammation in a mouse model of colitis.

BACKGROUND: Inflammatory bowel diseases (IBD) are chronic intestinal inflammatory diseases affecting about 1% of western populations. New eating behaviors might contribute to the global emergence of IBD. Although the immunoregulatory effects of omega-3 fatty acids have been well characterized in vitro, their role in IBD is controversial. METHODS: The aim of this study was to assess the impact of increased fish oil intake on colonic gene expression, eicosanoid metabolism and development of colitis in a mouse model of IBD. Rag-2 deficient mice were fed fish oil (FO) enriched in omega-3 fatty acids i.e. EPA and DHA or control diet for 4 weeks before colitis induction by adoptive transfer of naïve T cells and maintained in the same diet for 4 additional weeks. Onset of colitis was monitored by colonoscopy and further confirmed by immunological examinations. Whole genome expression profiling was made and eicosanoids were measured by HPLC-MS/MS in colonic samples. RESULTS: A significant reduction of colonic proinflammatory eicosanoids in FO fed mice compared to control was observed. However, neither alteration of colonic gene expression signature nor reduction in IBD scores was observed under FO diet. CONCLUSION: Thus, increased intake of dietary FO did not prevent experimental colitis.

Term infant formula supplemented with milk-derived oligosaccharides shifts the gut microbiota closer to that of human milk-fed infants and improves intestinal immune defense: a randomized controlled trial.

BACKGROUND: Bovine milk-derived oligosaccharides (MOS) containing primarily galacto-oligosaccharides with inherent concentrations of sialylated oligosaccharides can be added to infant formula to enhance the oligosaccharide profile. OBJECTIVE: To investigate the effects of an MOS-supplemented infant formula on gut microbiota and intestinal immunity. METHODS: In a double-blind, randomized, controlled trial, healthy term formula-fed infants aged 21-26 d either received an intact protein cow milk-based formula (control group, CG, n = 112) or the same formula containing 7.2 g MOS/L (experimental group, EG, n = 114) until the age of 6 mo. Exclusively human milk-fed infants (HFI, n = 70) from an observational study served as the reference. Fecal samples collected at baseline, and the ages of 2.5 and 4 mo were assessed for microbiota (16S ribosomal RNA-based approaches), metabolites, and biomarkers of gut health and immune response. RESULTS: Aged 2.5 and 4 mo, redundancy analysis (P = 0.002) and average phylogenetic distance (P < 0.05) showed that the overall microbiota composition in EG was different from CG and closer to that of HFI. Similarly, EG caesarean-born infants were different from CG caesarean- or vaginally born infants and approaching HFI vaginally born infants. Relative bifidobacteria abundance was higher in EG compared with CG (P < 0.05) approaching HFI. At the age of 4 mo, counts of Clostridioides difficile and Clostridium perfringens were ∼90% (P < 0.001) and ∼65% (P < 0.01) lower in EG compared with CG, respectively. Geometric LS mean (95% CI) fecal secretory IgA in EG was twice that of CG [70 (57, 85) compared with 34 (28, 42) mg/g, P < 0.001] and closer to HFI. Fecal oral polio vaccine-specific IgA was ∼50% higher in EG compared with CG (P = 0.065). Compared with CG, EG and HFI had lower fecal calcium excretion (by ∼30%, P < 0.005) and fecal pH (P < 0.001), and higher lactate concentration (P < 0.001). CONCLUSIONS: Infant formula with MOS shifts the gut microbiota and metabolic signature closer to that of HFI, has a strong bifidogenic effect, reduces fecal pathogens, and improves the intestinal immune response.

Metabolic phenotyping of the Crohn's disease-like IBD etiopathology in the TNF(ΔARE/WT) mouse model.

The underlying biochemical consequences of inflammatory bowel disease (IBD) on the systemic and gastrointestinal metabolism have not yet been fully elucidated but could help to better understand the disease pathogenesis and to identify tissue-specific markers associated with the different disease stages. Here, we applied a metabonomic approach to monitor metabolic events associated with the gradual development of Crohn's disease (CD)-like ileitis in the TNF(ΔARE/WT) mouse model. Metabolic profiles of different intestinal compartments from the age of 4 up to 24 weeks were generated by combining proton nuclear magnetic resonance ((1)H NMR) spectroscopy and liquid chromatography-mass spectrometry (LC-MS). From 8 weeks onward, mice developed CD similar to the immune and tissue-related phenotype of human CD with ileal involvement, including ileal histological abnormalities, reduced fat mass and body weight, as well as hallmarks of malabsorption with higher energy wasting. The metabonomic approach highlighted shifts in the intestinal lipid metabolism concomitant to the histological onset of inflammation. Moreover, the advanced disease status was characterized by a significantly altered metabolism of cholesterol, triglycerides, phospholipids, plasmalogens, and sphingomyelins in the inflamed tissue (ileum) and the adjacent intestinal parts (proximal colon). These results describe different biological processes associated with the disease onset, including modifications of the general cell membrane composition, alteration of energy homeostasis, and finally the generation of inflammatory lipid mediators. Taken together, this provides novel insights into IBD-related alterations of specific lipid-dependant processes during inflammatory states.

Potentiation of polarized intestinal Caco-2 cell responsiveness to probiotics complexed with secretory IgA.

The precise mechanisms underlying the interaction between intestinal bacteria and the host epithelium lead to multiple consequences that remain poorly understood at the molecular level. Deciphering such events can provide valuable information as to the mode of action of commensal and probiotic microorganisms in the gastrointestinal environment. Potential roles of such microorganisms along the privileged target represented by the mucosal immune system include maturation prior, during and after weaning, and the reduction of inflammatory reactions in pathogenic conditions. Using human intestinal epithelial Caco-2 cell grown as polarized monolayers, we found that association of a Lactobacillus or a Bifidobacterium with nonspecific secretory IgA (SIgA) enhanced probiotic adhesion by a factor of 3.4-fold or more. Bacteria alone or in complex with SIgA reinforced transepithelial electrical resistance, a phenomenon coupled with increased phosphorylation of tight junction proteins zonula occludens-1 and occludin. In contrast, association with SIgA resulted in both enhanced level of nuclear translocation of NF-κB and production of epithelial polymeric Ig receptor as compared with bacteria alone. Moreover, thymic stromal lymphopoietin production was increased upon exposure to bacteria and further enhanced with SIgA-based complexes, whereas the level of pro-inflammatory epithelial cell mediators remained unaffected. Interestingly, SIgA-mediated potentiation of the Caco-2 cell responsiveness to the two probiotics tested involved Fab-independent interaction with the bacteria. These findings add to the multiple functions of SIgA and underscore a novel role of the antibody in interaction with intestinal bacteria.

Lactobacillus paracasei reduces intestinal inflammation in adoptive transfer mouse model of experimental colitis.

Studies showed that specific probiotics provide therapeutic benefits in inflammatory bowel disease. In vitro evidence suggested that Lactobacillus paracasei also called ST11 (CNCM I-2116) is a potent strain with immune modulation properties. However, little is known about its capacity to alleviate inflammatory symptoms in vivo In this context, the main objective of this study was to investigate the role of ST11 on intestinal inflammation using the adoptive transfer mouse model of experimental colitis. Rag2(-/-) recipient mice were fed with ST11 (10(9) CFU/day)a month prior toinduce colitis by adoptive transfer of naive T cells. One month later, in clear contrast to nonfed mice, weight loss was significantly reduced by 50% in ST11-fed mice. Further analysis of colon specimens revealed a significant reduction neutrophil infiltration and mucosal expression of IL1ß, IL-6, and IL12 proinflammatory cytokines, whereas no consistent differences in expression of antibacterial peptides or tight junction proteins were observed between PBS and ST11-fed mice. All together, our results demonstrate that oral administration of ST11 was safe and had a significant preventive effect on colitis. We conclude that probiotics such as Lactobacillus paracasei harbor worthwhile in vivo immunomodulatory properties to prevent intestinal inflammation by nutritional approaches.

Tolerance, safety, and effect on the faecal microbiota of an enteral formula supplemented with pre- and probiotics in critically ill children.

OBJECTIVES: The aim of this study was to demonstrate the tolerance and safety of an enteral formula containing prebiotics/probiotics, and its effect on the faecal microbiota in critically ill children. SUBJECTS AND METHODS: Ninety-four patients between 1 and 3 years old under mechanical ventilation requiring enteral feeding were randomised to receive either a test formula containing a synbiotic blend (composed of 2 probiotic strains [Lactobacillus paracasei NCC 2461 and Bifidobacterium longum NCC 3001], fructooligosaccharides [FOS], inulin, and Acacia gum), or a control formula. Patients remained in the intensive care unit for 7 days and were examined at day 14. Tolerance was assessed by overall caloric intake and time to reach caloric goal. Safety was assessed by abdominal distention, vomiting, and stool frequency. Microbiota was analysed by culture- and molecular-based methods. RESULTS: Overall caloric intake and time to reach caloric goal were similar between groups (noninferiority was shown). Abdominal distention, vomiting, and stool frequency were not affected by the supplementation with pre- and probiotics. Faecal bifidobacteria were higher in the test group at the end of the study. A similar trend was observed for total lactobacilli. L paracasei NCC 2461 and B longum NCC 3001 were detected in 80.4% and 17% of the test group patients, respectively. Enterobacteria levels remained unchanged during hospitalisation in the control group but diminished in the test group. CONCLUSIONS: The enteral formula supplemented with synbiotics was well tolerated by children in intensive care units; it was safe and produced an increase in faecal bacterial groups of previously reported beneficial effects.

Characterization of the pathophysiological determinants of diarrheagenic Escherichia coli infection using a challenge model in healthy adults.

An experimental human challenge model with an attenuated diarrheagenic Escherichia coli (E. coli) strain has been used in food intervention studies aimed to increase resistance to E. coli infection. This study was designed to refine and expand this challenge model. In a double-blind study, healthy male subjects were orally challenged with 1E10 or 5E10 colony-forming units (CFU) of E. coli strain E1392/75-2A. Three weeks later, subjects were rechallenged with 1E10 CFU of E. coli. Before and after both challenges, clinical symptoms and infection- and immune-related biomarkers were analyzed. Subset analysis was performed on clinically high- and low-responders. Regardless of inoculation dose, the first challenge induced clinical symptoms for 2-3 days. In blood, neutrophils, CRP, CXCL10, and CFA/II-specific IgG were induced, and in feces calprotectin and CFA/II-specific IgA. Despite clinical differences between high- and low-responders, infection and immune biomarkers did not differ. The first inoculation induced protection at the second challenge, with a minor clinical response, and no change in biomarkers. The refined study design resulted in a larger dynamic range of symptoms, and identification of biomarkers induced by a challenge with the attenuated E. coli strain E1392/75-2A, which is of value for future intervention studies. Addition of a second inoculation allows to study the protective response induced by a primary infection.Clinicaltrials.gov registration: NCT02541695 (04/09/2015).

Lactobacillus paracasei CNCM I-2116 (ST11) inhibits substance P-induced skin inflammation and accelerates skin barrier function recovery in vitro.

Over the past few decades the number of people presenting reactive skin has increased in industrial countries. Skin inflammation mediated by neuropeptides and impaired skin barrier function are both underlying features of reactive skin conditions. Live microorganisms defined as probiotics have been successfully used to improve health status in humans. Beyond the effects on intestinal microbiota, some probiotic strains display potent immune-modulatory properties at the skin level. The aim of this study was to evaluate whether Lactobacillus paracasei CNCM-I 2116 (ST11) could modulate reactive skin-associated inflammatory mechanisms. The Caco-2/PBMC co-culture cell system was stimulated on the apical side with probiotics. The resulting medium collected from the basolateral compartment of the cell culture system, so called conditioned medium, was tested in ex vivo human abdominal plastic skin explant models of substance P-induced skin inflammation and skin barrier reconstruction. We show that ST11 was able to abrogate vasodilation, edema, mast cell degranulation and TNF-alpha release induced by substance P, compared to control. Moreover, using ex vivo skin organ culture, we show that ST11-conditioned medium induced a significantly faster barrier function recovery after SLS disruption, compared to control. These results support a beneficial role of ST11 on key biological processes associated with barrier function and skin reactivity.

Early Effect of Supplemented Infant Formulae on Intestinal Biomarkers and Microbiota: A Randomized Clinical Trial.

BACKGROUND: Post-natal gut maturation in infants interrelates maturation of the morphology, digestive, and immunological functions and gut microbiota development. Here, we explored both microbiota development and markers of gut barrier and maturation in healthy term infants during their early life to assess the interconnection of gut functions during different infant formulae regimes. METHODS: A total of 203 infants were enrolled in this randomized double-blind controlled trial including a breastfed reference group. Infants were fed starter formulae for the first four weeks of life, supplemented with different combination of nutrients (lactoferrin, probiotics (Bifidobacterium animal subsp. Lactis) and prebiotics (Bovine Milk-derived Oligosaccharides-BMOS)) and subsequently fed the control formula up to eight weeks of life. Stool microbiota profiles and biomarkers of early gut maturation, calprotectin (primary outcome), elastase, α-1 antitrypsin (AAT) and neopterin were measured in feces at one, two, four, and eight weeks. RESULTS: Infants fed formula containing BMOS had lower mean calprotectin levels over the first two to four weeks compared to the other formula groups. Elastase and AAT levels were closer to levels observed in breastfed infants. No differences were observed for neopterin. Global differences between the bacterial communities of all groups were assessed by constrained multivariate analysis with hypothesis testing. The canonical correspondence analysis (CCA) at genus level showed overlap between microbiota profiles at one and four weeks of age in the BMOS supplemented formula group with the breastfed reference, dominated by bifidobacteria. Microbiota profiles of all groups at four weeks were significantly associated with the calprotectin levels at 4 (CCA, p = 0.018) and eight weeks of age (CCA, p = 0.026). CONCLUSION: A meaningful correlation was observed between changes in microbiota composition and gut maturation marker calprotectin. The supplementation with BMOS seems to favor gut maturation closer to that of breastfed infants.

Oral supplementation with Lactobacillus rhamnosus CGMCC 1.3724 prevents development of atopic dermatitis in NC/NgaTnd mice possibly by modulating local production of IFN-gamma.

Prevalence of allergies has increased during the last two decades. Alteration of the gut microbiota composition is thought to play a crucial role in development of atopic diseases. Oral administration of probiotics has been reported to treat and/or prevent symptoms of atopic diseases in infants, but the results are still controversial. We investigated the potential efficacy of dietary interventions by a probiotic strain on prevention and treatment of atopic dermatitis (AD) in a human-like AD model, NC/NgaTnd mice by perinatal administration. Pregnant NC/NgaTnd mice were orally treated with the probiotic strain Lactobacillus rhamnosus CGMCC 1.3724 (LPR), which was followed by treatment of pups until 12 weeks of age. LPR-treated mice exhibited significant lower clinical symptoms of dermatitis, reduced scratching frequency, lower levels of plasma total Immunoglobulin E and higher levels of interferon-gamma in skin biopsies, compared with untreated mice. The protective effect was also observed when mice started to be treated at weaning time (5 weeks of age) even with limited supplementation period of 2 weeks. However, treatment of mice with the probiotic starting 1 week after the onset of the disease (8 weeks of age) had limited effects. The usefulness of LPR for primary prevention of AD was supported.

Feeding a diet containing a fructooligosaccharide mix can enhance Salmonella vaccine efficacy in mice.

Fructooligosaccharides (FOS) are considered prebiotics because of their ability to promote growth of specific beneficial gut bacteria, such as bifidobacteria. Some studies reported potential immune-modulating properties. The aim of this study was to investigate the effect of FOS:inulin mix on murine response to Salmonella vaccine and evaluate the relevance toward protection against Salmonella infection. Balb/c mice were fed a diet containing 5% FOS:inulin mix or a control diet 1 wk before oral immunization with a suboptimal dose of live attenuated Salmonella typhimurium vaccine. Four weeks after vaccination, mice were infected with LD100 of virulent S. typhimurium. Specific blood Salmonella immunoglobulin G and fecal immunoglobulin A significantly increased in mice fed the diet containing prebiotics compared with control mice 4 wk postimmunization. Peritoneal macrophage phagocytic activity also significantly increased in FOS:inulin-fed mice at 1 wk postimmunization compared with control mice. No detectable effects were observed on the percentage of lymphoid cell subsets in the spleen. However, production of cytokines, interferon-gamma, interleukin-12, and tumor necrosis factor alpha, was numerically increased in spleen cell cultures stimulated with mitogens from FOS:inulin-fed mice 1 and 4 wk postimmunization. Salmonella translocation to lymphoid organs was not affected by feeding FOS:inulin. However, the improved response to Salmonella vaccine was concomitant with an increase in the survival rate of FOS:inulin-fed mice upon challenge with virulent Salmonella. No detectable effects were observed on the composition or the metabolic activity of the microbiota. Overall, the data suggest that a diet supplemented with FOS:inulin mix stimulates mucosal immunity and seems to improve efficacy of an oral vaccine.

Effect of Lactobacillus paracasei NCC2461 on antigen-specific T-cell mediated immune responses in aged mice.

Aging is associated with a reduced capacity to mount proper immune responses, in particular to vaccines. Probiotic lactic acid bacteria may improve the immune status of the elderly; however, there is little evidence showing an effect of these bacteria on humoral and cellular immune responses. In the present study, the immunomodulatory capacity of the probiotic Lactobacillus paracasei NCC2461 combined or not with a prebiotic composition, FOS/inulin, was examined in aged mice. Male C57BL/6J mice (21-months-old) were allocated to one of three groups fed ad libitum for 44 days with different diets: a normal diet (control), a normal diet plus NCC2461 given in the drinking water, or a diet containing FOS/inulin plus NCC2461 in the drinking water. All mice were immunized on day 15 and challenged on day 22 with keyhole limpet hemocyanin (KLH). T helper (Th)1 cell-dependent immune responses (anti-KLH immunoglobulin G(2a) [IgG(2a)] levels and delayed type hypersensitivity response) were increased significantly in NCC2461-supplemented mice when compared to controls. Supplementation with FOS/inulin did not further improve the immune-enhancing effect mediated by the probiotic. Splenocyte proliferation, T cell subsets, systemic total IgG levels, and mucosal total IgA responses were not affected. Interestingly, supplementation with NCC2461 modulated the intestinal microbiota composition by increasing the numbers of bifidobacteria and lactobacilli. In conclusion, oral intake of L. paracasei NCC2461 by aged mice enhanced the specific adaptive immune response to in vivo antigenic challenge without altering other cellular and humoral immune responses. The poor responsiveness to antigenic challenge, frequently observed in elderly people, may be improved by supplementation with L. paracasei NCC2461.

Prophylactic effect of oral administration of Lactobacillus johnsonii NCC533 (La1) during the weaning period on atopic dermatitis in NC/NgaTnd mice.

Bacterial exposure in infancy may be one of the determinants of atopic dermatitis (AD) morbidity in later life. Some clinical studies have shown that an intake of probiotics reduced the risks of AD in children; however, the timing and duration of administration for the prevention of AD still remain unclear. The aim of this study was to evaluate the effects on AD development of the administration of Lactobacillus johnsonii NC553 (La1) during the weaning period, using an animal model of human AD, NC/NgaTnd mice. La1 suspended in drinking water was administered to 4-week-old NC/NgaTnd mice for 4 weeks. Mice were kept up to 16 weeks of age in an air uncontrolled conventional condition. Clinical skin severity, scratching behaviour, histological features, and production of regulatory or inflammatory cytokines in spleens were analyzed. The results indicated that oral administration of La1 suppressed exacerbation of the clinical severity of dermatitis when compared to the controls. Scratching duration, which is the most important cause of skin damage, was also suppressed in mice fed with La1. La1 supplementation also suppressed epidermal hyperplasia and infiltration of inflammatory cells in skin. This study showed that exposure to La1 from the early stages might be beneficial to reduce the exacerbation of AD in children at high-risk of allergy.

Effect of supplementation with Enterococcus faecium (SF68) on immune functions in cats.

T evaluate the effect of supplementation with Enterococcus faecium strain SF68 (NCIMB10415) on immune function, responses to a multivalent vaccine were investigated in kittens given palatability enhancer with or without E. faecium SF68 daily. E. faecium SF68 was detected in the feces of seven of nine treated cats. Supplementation of kittens with E. faecium SF68 did not affect developmental parameters. The percentage of CD4+ lymphocytes was significantly higher in the treatment group. There were no statistical differences in measurements of any other nonspecific or specific immune parameters between groups.