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Biomedical subjects

Erika Isolauri

Publications and source records attributed to Erika Isolauri.

At least 37 records · Page 2Linked to original sources

Novel approaches to the nutritional management of the allergic infant.

The increased prevalence of atopic diseases, i.e. atopic eczema, allergic rhinitis and asthma, has been described as the epidemic of the 21st century in Western societies. New approaches in the fight against allergic diseases are clearly called for, the target being the persistence of the allergic responder pattern beyond infancy. The advantage afforded by elimination diets lies in the silencing of specific allergic inflammation induced by an offending food. Novel nutritional approaches, beyond the treatment of food allergies, have recently attracted research interest subsequent to the identification of the immunomodulatory potential of specific dietary compounds. Dietary lipids as immunomodulators may prevent allergic sensitization by down-regulating inflammatory response whilst protecting the epithelial barrier. Probiotic bacteria have been shown to reinforce the different lines of gut defence: immune exclusion, immune elimination and immune regulation. On this basis, the strategy against allergic disease proposed here is based on the administration of tolerogenic gut-processed peptide fragments of a specific protein, in addition to the use of specific dietary compounds such as fatty acids and antioxidants, and introducing a microbial stimulus for the immature immune system by means of cultures of beneficial live micro-organisms characteristic of the healthy infant gut microbiota.

Dinoprostone↗

Transmission of high-risk human papillomavirus (HPV) between parents and infant: a prospective study of HPV in families in Finland.

The Finnish HPV Family Study is a prospective cohort study assessing the dynamics of human papillomavirus (HPV) transmission between parents and infant. Serial genital and oral scrapings from 76 families, including mother, father, and infant, and semen samples were collected over 2 years of follow-up, analyzed by nested PCR, and confirmed by hybridization with 12 high-risk (HR) HPV types. The most common HPV profile was HR HPV in all family members (29%), followed by HPV-positive mother-infant pairs (26%). HPV-positive father-infant pairs were less frequent (11%), and in six (8%) families, only the infant was HR HPV positive. The prevalence of genital HR HPV in the parents ranged from 13 to 25%, and that of oral HPV ranged from 8 to 34%. In the infants, HPV DNA was detected in 15% of the genital and 10% of the oral samples at birth, reaching peaks of 18 and 21%, respectively, at 6 months, and declining to 10% at 24 months. Persistent HPV in the mother was a risk factor for oral HPV in the infant (odds ratio [OR], 5.69; 95% confidence interval [95% CI], 1.5 to 21.3), while oral HPV in the mother at 6 months was a risk factor for genital HR HPV (OR, 6.38; 95% CI, 1.15 to 35.32). No such independent risk could be attributed to subclinical HPV in the father. Persistent maternal cervical HPV and subclinical oral HPV affect the risk of infant HPV. The age of 6 months is a critical point for the infant to acquire or be free of HR HPV DNA.

Adult↗

Characterization of breast milk received by infants with gross blood in stools.

OBJECTIVE: The aim of this study was to ascertain factors that might be protective of the appearance of gross blood in the stools of breast-fed infants. METHODS: Logistic regression models were formed to search for variables possibly explaining the condition. In addition to the analyzed breast milk factors, mother's allergic disease was introduced into the models to control for its possible confounding effect. The breast milk samples, collected from mothers of infants with gross blood in stools (n = 23) and from mothers of healthy age-matched infants (n = 71), were analyzed for concentrations of transforming growth factor-beta2, tumor necrosis factor-alpha, interleukin (IL)-4, IL-10, prostaglandin (PG)E2, cysteinyl leukotrienes (Cys-LTs) and fatty acid composition. RESULTS AND CONCLUSIONS: Increase in the concentrations of PGE2 and Cys-LTs in the breast milk together with mother's allergic disease reduced the likelihood of gross blood in stools in the breast-fed infant. The results suggest that no single factor, but a combination of immunomodulatory factors may protect the child from gross blood in the stools of breast-fed infants. Allergic disease was not a risk factor as mother's allergic disease appeared to counterbalance the gross blood in stools. Due to the preliminary nature of the study, the results need to be verified in a larger setting. The challenge for the future lies in identifying of such active compounds for dietary modification to enforce particularly the properties of the breast milk which are immunoprotective for the infant and to reduce the likelihood of intestinal disorders in at risk infants.

Blood↗

PASSCLAIM--gut health and immunity.

BACKGROUND: The gut and immune system form a complex integrated structure that has evolved to provide effective digestion and defence against ingested toxins and pathogenic bacteria. However, great variation exists in what is considered normal healthy gut and immune function. Thus, whilst it is possible to measure many aspects of digestion and immunity, it is more difficult to interpret the benefits to individuals of variation within what is considered to be a normal range. Nevertheless, it is important to set standards for optimal function for use both by the consumer, industry and those concerned with the public health. The digestive tract is most frequently the object of functional and health claims and a large market already exists for gut-functional foods worldwide. AIM: To define normal function of the gut and immune system and describe available methods of measuring it. RESULTS: We have defined normal bowel habit and transit time, identified their role as risk factors for disease and how they may be measured. Similarly, we have tried to define what is a healthy gut flora in terms of the dominant genera and their metabolism and listed the many, varied and novel methods for determining these parameters. It has proved less easy to provide boundaries for what constitutes optimal or improved gastric emptying, gut motility, nutrient and water absorption and the function of organs such as the liver, gallbladder and pancreas. The many tests of these functions are described. We have discussed gastrointestinal well being. Sensations arising from the gut can be both pleasant and unpleasant. However, the characteristics of well being are ill defined and merge imperceptibly from acceptable to unacceptable, a state that is subjective. Nevertheless, we feel this is an important area for future work and method development. The immune system is even more difficult to make quantitative judgements about. When it is defective, then clinical problems ensure, but this is an uncommon state. The innate and adaptive immune systems work synergistically together and comprise many cellular and humoral factors. The adaptive system is extremely sophisticated and between the two arms of immunity there is great redundancy, which provides robust defences. New aspects of immune function are discovered regularly. It is not clear whether immune function can be "improved". Measuring aspects of immune function is possible but there is no one test that will define either the status or functional capacity of the immune system. Human studies are often limited by the ability to sample only blood or secretions such as saliva but it should be remembered that only 2% of lymphocytes circulate at any given time, which limits interpretation of data. We recommend assessing the functional capacity of the immune system by: measuring specific cell functions ex vivo. measuring in vivo responses to challenge, e. g. change in antibody in blood or response to antigens. determining the incidence and severity of infection in target populations during naturally occurring episodes or in response to attenuated pathogens.

Constipation↗

Dietary modification of atopic disease: Use of probiotics in the prevention of atopic dermatitis.

The increased prevalence of atopic diseases, atopic dermatitis, allergic rhinitis, and asthma has been described as an epidemic. New approaches in the fight against allergic diseases are called for, the target being the persistence of the atopic T helper 2-skewed immune responder pattern beyond infancy. Atopic dermatitis, the earliest of these conditions, might act as a portal for the development of IgE-mediated atopic manifestations. Abundant evidence implies that specific strains selected from the healthy gut microbiota exhibit powerful antipathogenic and anti-inflammatory capabilities, and several targets for the probiotic approach have emerged in atopic dermatitis: degradation/structural modification of enteral antigens, normalization of the properties of aberrant indigenous microbiota and of gut barrier functions, regulation of the secretion of inflammatory mediators, and promotion of the development of the immune system. Better understanding of the effects of different probiotic strains and deeper insight into the mechanisms of the heterogeneous manifestations of atopic disease are needed for the validation of specific strains carrying anti-allergic potential.

Dermatitis, Atopic↗

Microbial-gut interactions in health and disease. Probiotics.

The definition of probiotics has evolved from a live active culture which improves the balance of the gut microbiota composition to specific effects, in particular, the immunomodulatory potential of clearly defined strains. The strains with beneficial properties, potential sources of probiotics, most frequently belong to the genera Bifidobacterium and Lactobacillus, and some of these strains exhibit powerful anti-inflammatory properties. Indeed, probiotic therapy has attracted research interest in human infectious, inflammatory and allergic disease. The most fully documented disease altering the gut microbiota is acute infectious diarrhoea in childhood. Current probiotic research aims to provide safe but sufficient bacterial stimulus in order to avert deviant immune responsiveness related to allergic and inflammatory diseases. However, further rigorous scientific efforts are required to characterize the immunomodulatory potential of specific probiotic strains for these targets.

Bifidobacterium↗

Probiotics and down-regulation of the allergic response.

The first clinical trials with probiotics, especially in the treatment of atopic eczema, have yielded encouraging results. Experimental studies have found that probiotics exert strain-specific effects in the intestinal lumen and on epithelial cells and immune cells with anti-allergic potential. These effects include enhancement in antigen degradation and gut barrier function and induction of regulatory and proinflammatory immune responses, the latter of which occurs more likely beyond the intestinal epithelium. Future studies should address more accurately how these and other possible mechanisms operate in the complex gastrointestinal macroenvironment in vivo and how these mechanisms are related to the clinical effects in a dose-dependent manner.

Humans↗

Weaning to hypoallergenic formula improves gut barrier function in breast-fed infants with atopic eczema.

OBJECTIVES: Infants may be sensitized to dietary antigens even during exclusive breast-feeding. Because food antigen traces in breast milk may have harmful effects on gut barrier function in infants with atopy, the authors sought to evaluate whether or not it is beneficial to shift such infants from breast milk to a hypoallergenic formula. METHODS: Fifty-six infants (mean age, 5.0 months) manifesting atopic eczema during exclusive breast-feeding were studied at weaning to a tolerated hypoallergenic formula. The urinary recovery ratios of orally administered lactulose and mannitol, fecal alpha-1 antitrypsin and urinary methylhistamine, and eosinophil protein X concentrations were assessed during breast-feeding and after weaning. RESULTS: The median (interquartile range, IQR) concentration of fecal alpha-1 antitrypsin was 2.3 mg/g (range, 1.2-3.3 mg/g) during breast-feeding and 0 (0.0-1.9 mg/g) after weaning to a tolerated hypoallergenic formula, z = -4.23, P < 0.0001. The urinary recovery ratio of lactulose and mannitol decreased from 0.029 (range, 0.021-0.042) to 0.023 (range, 0.016-0.031), respectively, z = -3.45, P = 0.0006. Concomitantly, the atopic eczema improved, and the concentration of urinary eosinophil protein X decreased significantly. CONCLUSIONS: In breast-fed infants with atopy, gut barrier function is improved after cessation of breast-feeding and starting of hypoallergenic formula feeding.

Animals↗

The hygiene hypothesis of atopic disease--an extended version.

The hygiene hypothesis of atopic disease suggests that environmental changes in the industrialized world have lead to reduced microbial contact at an early age and thus resulted in the growing epidemic of atopic eczema, allergic rhinoconjunctivitis, and asthma. The epidemiological findings have been combined with the Th1/Th2 paradigm of immune responsiveness to provide a coherent theory. Recent advances in epidemiology and immunology demonstrate, however, that the hygiene hypothesis may need to be extended in three respects. First, the importance of infections in causing immune deviance may be outweighed by other sources of microbial stimulation, perhaps most importantly by the indigenous intestinal microbiota. Second, immunomodulatory and suppressive immune responses complement the Th1/Th2 paradigm. Third, in addition to protection against atopy, protection against infectious, inflammatory, and autoimmune diseases may also depend upon healthy host-microbe interactions implicated in the hygiene hypothesis.

Child, Preschool↗

Cow's milk allergy in infants with atopic eczema is associated with aberrant production of interleukin-4 during oral cow's milk challenge.

OBJECTIVES: A failure in the establishment and maintenance of oral tolerance in infancy may result in food allergy. To further assess the role of the intestinal immune system in cow's milk allergy (CMA), we investigated the systemic production of the pro-allergenic Th2 cytokine interleukin (IL)-4 and anti-allergenic cytokines IL-10, transforming growth factor (TGF)-beta1 and TGF-beta2 in infants suffering from atopic eczema with and without CMA during antigen elimination diet and oral antigen exposure. METHODS: 18 infants (mean age, 9.6 months; 95% confidence interval 8.1-11.1 months) with atopic eczema and CMA and 17 infants (mean age, 9.7 months; 95% confidence interval 8.6-10.9 months) with atopic eczema tolerant to milk as assessed by a double blind, placebo-controlled cow's milk challenge were investigated. Peripheral blood mononuclear cells were obtained during antigen elimination diet and during oral cow's milk challenge and stimulated with Concanavalin-A or cow's milk or were left unstimulated. The cytokine concentrations were measured by enzyme-linked immunosorbent assay. RESULTS: During antigen elimination, the Concanavalin A-stimulated production of TGF-beta2 was significantly lower in infants with CMA as compared with infants without CMA: 129 pg/mL (interquartile ratio, 124-144 pg/mL) vs. 149 pg/mL (interquartile ratio, 133-169 pg/mL); P = 0.016. During oral antigen exposure, the immune responses in infants with CMA were characterized by significantly higher spontaneous production of IL-4 as compared with those without CMA: 12.0 pg/mL (interquartile ratio, 5.2-28.3 pg/mL) vs. 4.2 pg/mL (interquartile ratio, 1.5-7.6 pg/mL); P = 0.018. CONCLUSIONS: Infants with atopic eczema and CMA exhibit markedly increased systemic pro-allergenic IL-4 responses on intestinal antigen contact, which may partially be explained by a defective ability to launch anti-allergenic TGF-beta2 responses.

Age of Onset↗

Microbiota composition of the intestinal mucosa: association with fecal microbiota?

The fecal and mucosal microbiota of infants with rectal bleeding and the fecal microbiota of healthy age-matched controls were investigated by fluorescent in situ hybridization. Bifidobacteria were the main genus in both the feces and mucosa. The other genera tested, Bacteroides, Clostridium, Escherichia coli and lactobacilli/enterococci, represented only minor constituents. No differences in fecal microbiota were observed between patients and controls. In the patients, however, four times greater numbers of bifidobacteria were observed in the feces when compared to the mucosa. Notwithstanding this difference, a strong positive correlation prevailed for bifidobacteria in feces and mucosal samples. The genera assessed accounted for 16% of total bacterial counts on mucosal samples and for 47% of total bacterial counts in feces. This indicates that the unidentified part of the microbiota, especially on the mucosa, deserves more attention.

Bacteria↗

Probiotics and prevention of atopic disease: 4-year follow-up of a randomised placebo-controlled trial.

Perinatal administration of the probiotic Lactobacillus rhamnosus strain GG (ATCC 53103), reduces incidence of atopic eczema in at-risk children during the first 2 years of life (infancy). We have therefore assessed persistence of the potential to prevent atopic eczema at 4 years. Atopic disease was diagnosed on the basis of a questionnaire and a clinical examination. 14 of 53 children receiving lactobacillus had developed atopic eczema, compared with 25 of 54 receiving placebo (relative risk 0.57, 95% CI 0.33-0.97). Skin prick test reactivity was the same in both groups: ten of 50 children previously given lactobacillus compared with nine of 50 given placebo tested positive. Our results suggest that the preventive effect of lactobacillus GG on atopic eczema extends beyond infancy.

Child, Preschool↗

Breast milk fatty acids, eicosanoids, and cytokines in mothers with and without allergic disease.

Allergic disease (AD), including atopic eczema, asthma, allergic rhinitis, and food allergy, is characterized by an imbalance between cytokines produced by distinct T-helper cell subtypes. Whether this imbalance can be transferred from mother to breast milk remains to be established. The objective was to investigate the concentrations and interactions of nutritional and inflammatory factors in breast milk. Breast milk samples were collected from mothers with AD (n = 43) and without AD (n = 51). The concentrations of transforming growth factor (TGF)-beta2, tumor necrosis factor-alpha, IL-4, IL-10, prostaglandin E2, and cysteinyl leukotrienes were measured by immunoassays and fatty acid composition by gas chromatography. Mothers with AD had a lower concentration of TGF-beta2 in breast milk [median (interquartile range), 420 (278-701) ng/L] compared with those without AD [539 (378-1108) ng/L; p = 0.003], whereas other cytokines, prostaglandin E2, and cysteinyl leukotriene concentrations or fatty acid composition were not significantly different between the groups. The breast milk inflammatory factors and fatty acid composition were shown to be related. A positive association was observed between TGF-beta2 and the proportion of polyunsaturated fatty acids (p = 0.038) and a negative association between TGF-beta2 and the proportion of saturated fatty acids (p = 0.029) in breast milk. The reduced TGF-beta2 concentration in the breast milk of mothers with AD may interfere with the development of the mucosal immune system of the breast-fed infant. The observed associations between nutritional and inflammatory factors in breast milk suggest that it may be possible to influence the immunologic properties of breast milk by dietary intervention of the mother.

Cytokines↗

Probiotic bacteria in the management of atopic disease: underscoring the importance of viability.

OBJECTIVES: The aim of this study was to assess the efficacy of oral supplementation of viable and heat-inactivated probiotic bacteria in the management of atopic disease and to observe their effects on the composition of the gut microbiota. METHODS: The study population included 35 infants with atopic eczema and allergy to cow's milk. At a mean age of 5.5 months, they were assigned in a randomized double-blind manner to receive either extensively hydrolyzed whey formula (placebo group) or the same formula supplemented with viable (viable LGG group) or heat-inactivated Lactobacillus GG (heat-inactivated LGG group), respectively. The changes in symptoms were assessed by the SCORAD method and the presence of some predominant bacterial genera in the feces detected with 16S rRNA-specific probes. RESULTS: The treatment with heat-inactivated LGG was associated with adverse gastrointestinal symptoms and diarrhea. Consequently, the recruitment of patients was stopped after the pilot phase. Within the study population, atopic eczema and subjective symptoms were significantly alleviated in all the groups; the SCORAD scores (interquartile range) decreased from 13 (range, 4-29) to 8 (range, 0-29) units in the placebo group, from 19 (range, 4-47) to 5 (range, 0-18) units in the viable LGG group, and from 15 (range, 0-29) to 7 (range, 0-26) units in the heat-inactivated LGG group. The decrease in the SCORAD scores within the viable LGG group tended to be greater than within the placebo group. The treatments did not appear to affect the bacterial numbers within the genera enumerated. CONCLUSIONS: Supplementation of infant formulas with viable but not heat-inactivated LGG is a potential approach for the management of atopic eczema and cow's milk allergy.

Administration, Oral↗

Role of intestinal flora in the development of allergy.

PURPOSE OF REVIEW: The frequency of allergic diseases is increasing worldwide. Experimental and clinical studies have linked a reduced number of early infections to this trend. The gastrointestinal system, which comprises the largest lymphoid tissue and microbial reservoir of the body, has received more attention during the last few years as a potential determiner in the development of atopic disease. RECENT FINDINGS: Alterations in intestinal microbiota have been detected both in infants suffering from allergic disease and in those later developing the disorder. Delay in the compositional development of and in gut microflora was a general finding in allergic children. In a subsequent study, perinatal administration of lactobacilli halved the later development of atopic eczema during the first 2 years of life. Specific strains of the healthy gut microbiota have been shown to induce the production of IL-10 and transforming growth factor-beta, which possess an important regulative role in the development of allergic type immune response. Probiotics also strengthen gut defence barrier mechanisms and reduce antigen load in the gut. Pattern recognition receptors in intestinal epithelial and antigen-presenting cells have been demonstrated to mediate a continuing dialogue between host and gut microbiota. SUMMARY: Despite several promising findings, the exact role of gut normal microbiota in the development of allergy remains to be elucidated. For successful interventions, more data concerning a communication between host and specific microbial species are needed.

Animals↗

Common respiratory infections early in life may reduce the risk of atopic dermatitis.

Infections that occur early in life may protect against atopic disease later in life. To investigate the relationship between common acute respiratory infections and atopic dermatitis in early childhood, we closely observed a cohort of 329 children from the ages of 2 to 24 months. We assessed the effect of proven viral infections and acute otitis media on the occurrence of atopic dermatitis. If the child had his or her first respiratory infection before the age of 6 months, the child's remaining risk of developing atopic dermatitis was reduced by 49% (95% confidence interval, -24% to 79%). The individual risk of developing atopic dermatitis was similarly reduced after infection experienced at >/=6 months of age, but the remaining risk was low, because most cases of atopic dermatitis had manifested by this time. Our results are consistent with the hypothesis that early infections may reduce the risk of atopic disease.

Child↗

The role of the intestinal microflora for the development of the immune system in early childhood.

The intestinal tract performs many different functions; in addition to absorption and digestion it is also the body's largest organ of host defence. Part of the intestinal mucosal barrier function is formed by a common mucosal immune system which provides communication between the different mucosal surfaces of the body. The intestine also contains a microbial ecosystem with a large body of microbes, 1-11/2 kg in an adult. The microbes and their activity have a major impact on the development and functioning of the intestinal immune system and vice versa. This mutual influence also affects the host beyond the intestine. The intestinal colonisation with a balanced microflora is of main importance for the correct development of the immune system. The importance of the intestinal microflora is most clearly seen in germfree animals, but also diseases like atopy are associated with disturbances in the intestinal microflora. This often manifests itself in a low number of bifidobacteria. The use of probiotics or prebiotics to correct this imbalance and modulate the immune activity has received increasing scientific documentation. The precise mechanisms behind these immune modulatory activities are not well understood and require further investigation.

Bifidobacterium↗