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Biomedical subjects

E Isolauri

Publications and source records attributed to E Isolauri.

At least 19 recordsLinked to original sources

Probiotics: a role in the treatment of intestinal infection and inflammation?

Probiotic therapy is based on the concept of normal healthy microflora. The development of novel means of characterising the gut microflora, in particular those based on the different levels of conservation in the ribosomal RNA sequences of different genera, have opened up new angles on the role of the gut microflora in health and disease. Components of the human intestinal microflora or organisms entering the intestine may have harmful or beneficial effects on human health. Abundant evidence implies that specific strains selected from the healthy gut microflora exhibit powerful antipathogenic and anti-inflammatory capabilities, and are consequently involved with enhanced colonisation resistance in the intestine. Realisation of this has led to the introduction of novel modes of therapeutic and prophylactic intervention based on the consumption of mono and mixed cultures of beneficial live microorganisms as probiotics.

Acute Disease↗

Aberrant composition of gut microbiota of allergic infants: a target of bifidobacterial therapy at weaning?

BACKGROUND: Recent data have outlined a relationship between the composition of the intestinal microflora and allergic inflammation, and demonstrated the competence of probiotics in downregulation of such inflammation. AIMS: Our aims were to characterise the relationship between gut microbes and the extent of allergic sensitisation and to assess whether the efficacy of bifidobacterial supplementation in the treatment of allergy could relate to modulation of the intestinal microbiota. METHODS: This randomised study included 21 infants with early onset atopic eczema of whom eight were intolerant (highly sensitised group (HSG)) and 13 tolerant (sensitised group (SG)) to extensively hydrolysed whey formula (EHF). In the SG, six were weaned to EHF without (placebo group (PG)) and seven to EHF with Bifidobacterium lactis Bb-12 supplementation (bifidobacteria treated group (BbG)). The faecal microflora of infants in the HSG was analysed only before weaning whereas in the SG the faecal microflora was analysed both before and after weaning. RESULTS: Infants in the HSG had greater numbers of lactobacilli/enterococci than those in the SG. Serum total IgE concentration correlated directly with Escherichia coli counts in all infants and with bacteroides counts in the HSG, indicating that the presence of these bacteria is associated with the extent of atopic sensitisation. The effect of supplementation was characterised as a decrease in the numbers of Escherichia coli and protection against an increase in bacteroides numbers during weaning. CONCLUSIONS: These data indicate that bifidobacterial supplementation appears to modify the gut microbiota in a manner that may alleviate allergic inflammation. Further studies are needed to confirm this conclusion.

Animals↗

Probiotics in primary prevention of atopic disease: a randomised placebo-controlled trial.

BACKGROUND: Reversal of the progressive increase in frequency of atopic disease would be an important breakthrough for health care and wellbeing in western societies. In the hygiene hypothesis this increase is attributed to reduced microbial exposure in early life. Probiotics are cultures of potentially beneficial bacteria of the healthy gut microflora. We assessed the effect on atopic disease of Lactobacillus GG (which is safe at an early age and effective in treatment of allergic inflammation and food allergy). METHODS: In a double-blind, randomised placebo-controlled trial we gave Lactobacillus GG prenatally to mothers who had at least one first-degree relative (or partner) with atopic eczema, allergic rhinitis, or asthma, and postnatally for 6 months to their infants. Chronic recurring atopic eczema, which is the main sign of atopic disease in the first years of life, was the primary endpoint. FINDINGS: Atopic eczema was diagnosed in 46 of 132 (35%) children aged 2 years. Asthma was diagnosed in six of these children and allergic rhinitis in one. The frequency of atopic eczema in the probiotic group was half that of the placebo group (15/64 [23%] vs 31/68 [46%]; relative risk 0.51 [95% CI 0.32-0.84]). The number needed to treat was 4.5 (95% CI 2.6-15.6). INTERPRETATIONS: Lactobacillus GG was effective in prevention of early atopic disease in children at high risk. Thus, gut microflora might be a hitherto unexplored source of natural immunomodulators and probiotics, for prevention of atopic disease.

Child, Preschool↗

The influence of polyunsaturated fatty acids on probiotic growth and adhesion.

The establishment of the intestinal microflora, and probiotic bacteria, may control the inflammatory conditions in the gut. As polyunsaturated fatty acids (PUFA) possess antimicrobial activities, they may deter the action of probiotics. We assessed whether free linoleic, gamma-linolenic, arachidonic, alpha-linolenic and docosahexaenoic acids at physiological concentrations in the growth media would influence the growth and adhesion of Lactobacillus GG (probiotic), Lactobacillus casei Shirota (probiotic) and Lactobacillus bulgaricus (dairy strain). Higher concentrations of PUFA (10-40 microg PUFA ml(-1)) inhibited growth and mucus adhesion of all tested bacterial strains, whilst growth and mucus adhesion of L. casei Shirota was promoted by low concentrations of gamma-linolenic acid and arachidonic acid (at 5 microg ml(-1)), respectively. PUFA also altered bacterial adhesion sites on Caco-2 cells. Caco-2 cells grown in the presence of arachidonic acid were less adhered to by all three bacterial strains. Yet, L. casei Shirota adhered better on Caco-2 cells grown in the presence of alpha-linolenic acid. As the adhesion to mucosal surfaces is pivotal in health promoting effects by probiotics, our results indicate that the action of probiotics in the gut may be modulated by dietary PUFA.

Bacterial Adhesion↗

Differences in composition and mucosal adhesion of bifidobacteria isolated from healthy adults and healthy seniors.

Fifty-one Bifidobacterium strains were isolated from the feces of healthy adults (30-40 years old) and seniors (older than 70 years of age). B. adolescentis, B. breve, B. infantis, and B. longum were isolated from the healthy adults and B. adolescentis and B. longum from elderly subjects. The tested bacteria bound, in vitro, to intestinal mucus in a strain dependent manner. The strains isolated from healthy adults, and especially B. adolescentis, bound better to intestinal mucus than those isolated from seniors. These results indicate that the mucosal adhesive properties of the human Bifidobacterium flora were reduced with the aging of the host. This shift to a Bifidobacterium flora with reduced adhesive abilities may explain the decrease in bifidobacteria levels in the intestinal microflora of aging people.

Adult↗

Suppression of T-cell activation by Lactobacillus rhamnosus GG-degraded bovine casein.

Earlier data indicate that Lactobacillus rhomnosus GG ATCC 53103 (L. GG), a commensal intestinal bacterial strain, promotes the degradation of proteins in the gut in vivo, and bovine casein hydrolysed with L. GG-derived proteases suppresses lymphocyte proliferation in vitro. The present study aimed to evaluate the effect of L. GG-degraded bovine casein on T-cell activation, i.e. IL-2 mRNA expression and protein kinase C (PKC) translocation. To this end, Northern blot analyses for IL-2 mRNA expression and PKC assays with and without L. GG-degraded casein were carried out on T cells isolated from 11 healthy adults. Cell cultures in 8-11 experiments contained 1 mg ml(-1) bovine casein in degraded or undegraded form in the presence of a mitogen, i.e. phorbol 12,13-dibutyrate plus calcium ionophore (PBDu + A23187) or anti-CD3. Also IL-2, IL-4 and IFN-gamma syntheses were determined in 24-h culture supernatants. IL-2 mRNA expression was reduced in experiments with L. GG-degraded casein. In parallel, the IL-2 concentration in PBDu + A23187-stimulated culture supernatants, expressed as geometric means (95% confidence interval), decreased from 15,892 (7174-35,203) pg ml(-1) to 4744 (2095-10,742) pg ml(-1) when containing L. GG-degraded casein. L. GG-degraded casein inhibited PKC translocation, the action resembling that of PKC inhibitor, RO31-8220. These results extend previous data on L. GG-degraded casein, showing in vitro the suppression of T-cell activation.

Animals↗

Breast milk--immunomodulatory signals against allergic diseases.

Breastfeeding holds a key position with regard to the increasing burden of allergic diseases in the industrialized countries. Not only does it provide the infant with nutrients for growth and development, it also confers immunological protection during a critical period in life, when the infant's own defense mechanisms are immature. A delicate balance of stimulatory, even inflammatory, maturational signals, together with a myriad of anti-inflammatory compounds, is transferred from mother to infant via breastfeeding. Breastfeeding mothers, however, do not constitute a uniform group. The composition of breast milk shows marked individual variation and so, consequently, does the success of breastfeeding in reducing the risk of disease. Recent clinical studies indicate that the potential of breastfeeding to counteract allergic disease may be promoted by dietary means. While uncoordinated elimination diets result in a risk of general nutritional inadequacy or deficiency of essential single nutrients, a balanced diet following current dietary recommendations, specifically containing fresh fruits and vegetables (antioxidants) and fat of predominantly vegetable origin, may be associated with a lower incidence of atopy in the infant. As early nutrition appears to program the subsequent health of the child, the importance of the maternal dietary composition during breastfeeding should be emphasized. In future, an improved understanding of the mechanisms of this programming may offer specific therapeutic modalities for the prevention of allergic disease.

Adjuvants, Immunologic↗

Polyunsaturated fatty acids in maternal diet, breast milk, and serum lipid fatty acids of infants in relation to atopy.

BACKGROUND: The increased consumption of n-6 polyunsaturated fatty acids (PUFA) has been shown to coincide with the increased prevalence of atopic diseases. We aimed to investigate whether maternal diet and atopic status influence the PUFA composition of breast milk and the serum lipid fatty acids of infants. METHODS: Maternal diet was assessed by a food questionnaire. The PUFA composition of breast milk obtained at 3 months from 20 allergic and 20 healthy mothers and of their infants' (10 atopic and 10 nonatopic/group of mothers) serum lipids was analyzed. RESULTS: Although no differences in maternal PUFA intake were observed, the breast milk of allergic mothers contained less gamma-linolenic acid (18:3 n-6) than that of healthy mothers. Similarly, atopic infants had less gamma-linolenic acid in phospholipids than healthy infants, although n-6 PUFA were elevated in other serum lipid fractions in atopic infants. The serum lipid fatty acids in atopic infants did not correlate with those in maternal breast milk. CONCLUSION: Our results suggest that dietary n-6 PUFA are not as readily transferred into breast milk or incorporated into serum phospholipids, but may be utilized for other purposes, such as eicosanoid precursors, in allergic/atopic individuals. Subsequently, high dietary proportions of n-6 PUFA, or reduced proportions of regulatory PUFA, such as gamma-linolenic acid and n-3 PUFA, may be a risk factor for the development of atopic disease.

Cholesterol Esters↗

Prospective, controlled, multi-center study on the effect of an amino-acid-based formula in infants with cow's milk allergy/intolerance and atopic dermatitis.

Cow's milk allergy/intolerance is treated by complete avoidance of cow's milk proteins. Because cow's milk is an important food for infants, its avoidance may lead to an increased risk of growth impairment. Whilst there is evidence for the beneficial effects of extensively hydrolyzed cow's milk formulate (eHF) in infants with cow's milk allergy/intolerance, little is known about the effects of amino-acid-based formulae (AA) in such infants. We therefore performed a prospective, controlled, multi-center trial to study the efficacy of AA in comparison with eHF, on the growth and clinical symptoms of 73 infants (median age 5.7 months) with cow's milk allergy/intolerance and atopic dermatitis. Cow's milk allergy/intolerance was proven in all infants by double-blind, placebo-controlled food-challenge. We observed a significant improvement in the SCORAD index in both groups, from a mean of 24.6, at entry, to a mean of 10.7 (p < 0.0001) after 6 months. In the AA group there was a significant increase in the length standard deviation score (p < 0.04), whilst there was no difference in the eHF group. The weight-for-length values were stable in both groups. The energy intake during the study was similar in both groups. Both an AA and eHF resulted in a significant clinical improvement in infants with an early onset of symptoms of cow's milk allergy/intolerance. Feeding an AA resulted in improved growth compared with feeding eHF, despite similar dietary intakes, and may therefore be considered as a beneficial alternative in infants with severe cow's milk allergy intolerance.

Animals↗

Distinct patterns of neonatal gut microflora in infants in whom atopy was and was not developing.

BACKGROUND: Improved hygiene has altered early microbial exposure by reducing childhood infections, which has been suggested as a cause for the continuously rising prevalence of atopic diseases. On the basis of both intensity and timing of stimulus, it has been hypothesized that exposure to commensal microflora may represent another key protective modulator of immunity against atopy and subsequent atopic diseases. OBJECTIVE: We sought to investigate whether differences in early gut microflora precede the later development of atopic sensitization. METHODS: Intestinal microflora from 76 infants at high risk of atopic diseases were analyzed at 3 weeks and 3 months of age by using conventional bacterial cultivation and 2 culture-independent methods, gas-liquid chromatography of bacterial cellular fatty acids and quantitative fluorescence in situ hybridization of bacterial cells. Infants evincing at least one positive skin prick reaction at 12 months were grouped as atopic subjects, and those without positive reactions were grouped as nonatopic subjects. RESULTS: Atopic sensitization was observed in 22 (29%) of 76 children. At 3 weeks, the bacterial cellular fatty acid profile in fecal samples differed significantly between infants in whom atopy was and was not developing (P =.005). By using fluorescence in situ hydridization, atopic subjects had more clostridia (geometric mean [95% confidence interval]: 9.3 x 10(7) [3.8-22.9 x 10(7)] vs 3.3 x 10(7) [1.8-6.1 x 10(7)], P =.04) and tended to have fewer bifidobacteria (1.8 x 10(9) [0.4-7.6 x 10(9)] vs 6.1 x 10(9) [2.5-14.6 x 10(9)], P =.11) in their stools than nonatopic subjects, resulting in a reduced ratio of bifidobacteria to clostridia (P =.03). The differences were not detected by bacterial cultivation. CONCLUSION: Differences in the neonatal gut microflora precede the development of atopy, suggesting a crucial role of the balance of indigenous intestinal bacteria for the maturation of human immunity to a nonatopic mode.

Humans↗

Could TH1 and TH2 diseases coexist? Evaluation of asthma incidence in children with coeliac disease, type 1 diabetes, or rheumatoid arthritis: a register study.

BACKGROUND: Asthma is generally regarded as a disease with strong T(H)2-type cytokine expression, whereas in autoimmune disorders, such as coeliac disease (CD), insulin-dependent diabetes mellitus (IDDM), and rheumatoid arthritis (RA), T(H)1-type expression is seen. According to the cross-regulatory properties of T(H)1 and T(H)2 cells, one would assume that these diseases exist in different patient populations. OBJECTIVE: We sought to test the hypothesis that asthma could exist in children with T(H)1-type diseases, such as CD, IDDM, and RA. METHODS: Comparison was made of the cumulative incidence of asthma in children with CD, IDDM, or RA by linking Finnish Medical Birth Register data on the whole 1987 birth cohort (n = 60,254 births) with the data of several national health registers to obtain information on the incidences of these diseases during the first 7 years of life. RESULTS: The cumulative incidence of asthma in children with CD (24.6%) or RA (10.0%) was significantly higher than in children without CD (3.4%) or RA (3.4%; P < .001 and P = .016, respectively). Asthma tended to be more common in children with IDDM than in children without IDDM. CONCLUSION: These data indicate that the T(H)1 and T(H)2 diseases can coexist, indicating a common environmental denominator behind the disease processes.

Arthritis, Rheumatoid↗

Quality assurance criteria for probiotic bacteria.

Acid and bile stability and intestinal mucosal adhesion properties are among the criteria used to select probiotic microbes. The quality control of probiotic cultures in foods traditionally has relied solely on tests to ensure that an adequate number of viable bacteria are present in the products throughout their shelf lives. Viability is an important factor, but not the only criterion for quality assurance. To be effective, probiotic strains must retain the functional health characteristics for which they were originally selected. Such characteristics include the ability to survive transit through the stomach and small intestine and to colonize the human gastrointestinal tract. In vitro test protocols can be readily adopted to examine the maintenance of a strain's ability to tolerate acidic conditions, survive and grow in the presence of bile, and metabolize selective substrates. Molecular techniques are also available to examine strain stability. Adhesion characterization may be an important quality-control method for assessing gut barrier effects. Adhesion has been related to shortening the duration of diarrhea, immunogenic effects, competitive exclusion, and other health effects. Adhesion properties should be carefully monitored, including adhesion to intestinal cells (eg, Caco-2) and human intestinal mucus. This article outlines the types of in vitro testing that can be used to ensure quality control of functional probiotic strains.

Bacteria↗

Probiotics: effects on immunity.

The gastrointestinal tract functions as a barrier against antigens from microorganisms and food. The generation of immunophysiologic regulation in the gut depends on the establishment of indigenous microflora. This has led to the introduction of novel therapeutic interventions based on the consumption of cultures of beneficial live microorganisms that act as probiotics. Among the possible mechanisms of probiotic therapy is promotion of a nonimmunologic gut defense barrier, which includes the normalization of increased intestinal permeability and altered gut microecology. Another possible mechanism of probiotic therapy is improvement of the intestine's immunologic barrier, particularly through intestinal immunoglobulin A responses and alleviation of intestinal inflammatory responses, which produce a gut-stabilizing effect. Many probiotic effects are mediated through immune regulation, particularly through balance control of proinflammatory and anti-inflammatory cytokines. These data show that probiotics can be used as innovative tools to alleviate intestinal inflammation, normalize gut mucosal dysfunction, and down-regulate hypersensitivity reactions. More recent data show that differences exist in the immunomodulatory effects of candidate probiotic bacteria. Moreover, distinct regulatory effects have been detected in healthy subjects and in patients with inflammatory diseases. These results suggest that specific immunomodulatory properties of probiotic bacteria should be characterized when developing clinical applications for extended target populations.

Adjuvants, Immunologic↗

Probiotics in human disease.

Western civilization is facing a progressive increase in immune-mediated, gut-related health problems, such as allergies and autoimmune and inflammatory diseases, and genetic factors are an unlikely explanation for these rapid increases in disease incidence. Two environmental factors that relate to the modern lifestyle in Western societies are hygiene and nutrition. There has been a decline in the incidence of microbial stimulation by infectious diseases as a result of improved hygiene, vaccination, and antimicrobial medication. In the past, methods of food preservation involved either the natural fermentation or drying of foods; thus, the human diet once contained several thousand times more bacteria than it does today. The development of probiotic, functional foods aims to "kill two birds with one stone," which is accomplished by providing a microbial stimulus to the host immune system by means of beneficial live microorganism cultures that are characteristic of the healthy, human gut microflora, ie, probiotics. Probiotic bacteria were shown to reinforce the different lines of gut defense, which are immune exclusion, immune elimination, and immune regulation. They were also shown to stimulate nonspecific host resistance to microbial pathogens, thereby aiding in pathogen eradication. Consequently, the best documented clinical application of probiotics is in the treatment of acute diarrhea. In humans, documented effects were reported for the alleviation of intestinal inflammation, normalization of gut mucosal dysfunction, and down-regulation of hypersensitivity reactions. These data show that probiotics promote endogenous host defense mechanisms. Thus, modification of gut microflora by probiotic therapy may offer a therapeutic potential in clinical conditions associated with gut-barrier dysfunction and inflammatory response.

Diet↗