Prebiotics, probiotics and synbiotics are known to have major beneficial effects on human health due to their ability to modify the composition and the function of the gut mucosa, the gut microbiota ...and the immune system. These components largely function in a healthy population throughout different periods of life to confer homeostasis. Indeed, they can modulate the composition of the gut microbiota by increasing bacteria strands that are beneficial for health, such as
and
, and decreasing harmful bacteria, such as
. Their immunomodulation properties have been extensively studied in different innate cells (dendritic cells, macrophages, monocytes) and adaptive cells (Th, Treg, B cells). They can confer a protolerogenic environment but also modulate pro-inflammatory responses. Due to all these beneficial effects, these compounds have been investigated to prevent or to treat different diseases, such as cancer, diabetes, allergies, autoimmune diseases, etc. Regarding the literature, the effects of these components on dendritic cells, monocytes and T cells have been studied and presented in a number of reviews, but their impact on B-cell response has been less widely discussed.
For the first time, we propose here a review of the literature on the immunomodulation of B-lymphocytes response by prebiotics, probiotics and synbiotics, both in healthy conditions and in pathologies.
Promising studies have been performed in animal models, highlighting the potential of prebiotics, probiotics and synbiotics intake to treat or to prevent diseases associated with B-cell immunomodulation, but this needs to be validated in humans with a full characterization of B-cell subsets and not only the humoral response.
Breastmilk is known to be very important for infants because it provides nutrients and immunological compounds. Among these compounds, human milk oligosaccharides (HMOs) represent the third most ...important component of breastmilk after lipids and lactose. Several experiments demonstrated the beneficial effects of these components on the microbiota, the immune system and epithelial barriers, which are three major biological systems. Indeed, HMOs induce bacterial colonization in the intestinal tract, which is beneficial for health. The gut bacteria can act directly and indirectly on the immune system by stimulating innate immunity and controlling inflammatory reactions and by inducing an adaptive immune response and a tolerogenic environment. In parallel, HMOs directly strengthen the intestinal epithelial barrier, protecting the host against pathogens. Here, we review the molecular mechanisms of HMOs in these different compartments and highlight their potential use as new therapeutic agents, especially in allergy prevention.
Inflammatory bowel diseases (IBD), a heterogeneous group of inflammatory conditions that encompass both ulcerative colitis and Crohn's disease, represent a major public health concern. The etiology ...of IBD is not yet fully understood and no cure is available, with current treatments only showing long-term effectiveness in a minority of patients. A need to increase our knowledge on IBD pathophysiology is growing, to define preventive measures, to improve disease outcome, and to develop new effective and lasting treatments. IBD pathogenesis is sustained by aberrant immune responses, associated with alterations of the intestinal epithelial barrier (IEB), modifications of the enteric nervous system, and changes in microbiota composition. Currently, most of the treatments target the inflammation and the immune system, but holistic approaches targeting lifestyle and diet improvements are emerging. As dysbiosis is involved in IBD pathogenesis, pre-, pro-, syn-, and postbiotics are used/tested to reduce the inflammation or strengthen the IEB. The present review will resume these works, pointing out the stage of life, the duration, and the environmental conditions that should go along with microbiota or microbiota-derived treatments.
Allergic diseases now affect over 30% of individuals in many communities, particularly young children, underscoring the need for effective prevention strategies in early life. These allergic ...conditions have been linked to environmental and lifestyle changes driving the dysfunction of three interdependent biological systems: microbiota, epithelial barrier and immune system. While this is multifactorial, dietary changes are of particular interest in the altered establishment and maturation of the microbiome, including the associated profile of metabolites that modulate immune development and barrier function. Prebiotics are non-digestible food ingredients that beneficially influence the health of the host by 1) acting as a fermentable substrate for some specific commensal host bacteria leading to the release of short-chain fatty acids in the gut intestinal tract influencing many molecular and cellular processes; 2) acting directly on several compartments and specifically on different patterns of cells (epithelial and immune cells). Nutrients with prebiotic properties are therefore of central interest in allergy prevention for their potential to promote a more tolerogenic environment through these multiple pathways. Both observational studies and experimental models lend further credence to this hypothesis. In this review, we describe both the mechanisms and the therapeutic evidence from preclinical and clinical studies exploring the role of prebiotics in allergy prevention.
Food allergy is associated with alterations in the gut microbiota, epithelial barrier, and immune tolerance. These dysfunctions are observed within the first months of life, indicating that early ...intervention is crucial for disease prevention. Preventive nutritional strategies with prebiotics are an attractive option, as prebiotics such as galacto-oligosaccharides and inulin can promote tolerance, epithelial barrier reinforcement, and gut microbiota modulation. Nonetheless, the ideal period for intervention remains unknown. Here, we investigated whether galacto-oligosaccharide/inulin supplementation during gestation could protect offspring from wheat allergy development in BALB/cJRj mice. We demonstrated that gestational prebiotic supplementation promoted the presence of beneficial strains in the fecal microbiota of dams during gestation and partially during mid-lactation. This specific microbiota was transferred to their offspring and maintained to adulthood. The presence of B and T regulatory immune cell subsets was also increased in the lymph nodes of offspring born from supplemented mothers, suggestive of a more tolerogenic immune environment. Indeed, antenatal prebiotic supplementation reduced the development of wheat allergy symptoms in offspring. Our study thus demonstrates that prebiotic supplementation during pregnancy induces, in the offspring, a tolerogenic environment and a microbial imprint that mitigates food allergy development.
The gut microbiota is influenced by environmental factors such as food. Maternal diet during pregnancy modifies the gut microbiota composition and function, leading to the production of specific ...compounds that are transferred to the fetus and enhance the ontogeny and maturation of the immune system. Prebiotics are fermented by gut bacteria, leading to the release of short-chain fatty acids that can specifically interact with the immune system, inducing a switch toward tolerogenic populations and therefore conferring health benefits. In this study, pregnant BALB/cJRj mice were fed either a control diet or a diet enriched in prebiotics (Galacto-oligosaccharides/Inulin). We hypothesized that galacto-oligosaccharides/inulin supplementation during gestation could modify the maternal microbiota, favoring healthy immune imprinting in the fetus. Galacto-oligosaccharides/inulin supplementation during gestation increases the abundance of
and decreases that of
in the gut microbiota, leading to increased production of fecal acetate, which was found for the first time in amniotic fluid. Prebiotic supplementation increased the abundance of regulatory B and T cells in gestational tissues and in the fetus. Interestingly, these regulatory cells remained later in life. In conclusion, prebiotic supplementation during pregnancy leads to the transmission of specific microbial and immune factors from mother to child, allowing the establishment of tolerogenic immune imprinting in the fetus that may be beneficial for infant health outcomes.
Maternal diet during pregnancy plays a likely role in infant immune development through both direct nutrient specific immunomodulatory effects and by modulating the composition and metabolic activity ...of the maternal gut microbiome. Dietary fibers, as major substrates for microbial fermentation, are of interest in this context. This is the first study to examine maternal intakes of different fiber sub-types and subsequent infant allergic disease. In an observational study of 639 mother-infant pairs (all infants had a family history of allergic disease) we examined maternal intakes of total fiber, soluble fiber, insoluble fiber, resistant starch, and prebiotic fiber, by a semi-quantitative food frequency questionnaire at 36-40 weeks' gestation. Infants attended an allergy clinical assessment at 12 months of age, including skin prick testing to common allergens. Higher maternal dietary intakes of resistant starch were associated with reduced doctor diagnosed infant wheeze, adjusted odds ratio (aOR) 0.68 (95% CI 0.49, 0.95,
= 0.02). However, in contrast, higher maternal intakes of resistant starch were associated with higher risk of parent reported eczema aOR 1.27 (95% CI 1.09, 1.49,
< 0.01) and doctor diagnosed eczema aOR 1.19 (95% CI 1.01, 1.41,
= 0.04). In conclusion, maternal resistant starch consumption was differentially associated with infant phenotypes, with reduced risk of infant wheeze, but increased risk of eczema.
Hen's egg allergy is the second most frequent food allergy found in children. Allergic symptoms can be caused by raw or heated egg, but a majority of egg‐allergic children can tolerate hard‐boiled or ...baked egg. Understanding the reasons for the tolerance towards heated egg provides clues about the molecular mechanisms involved in egg allergy, and the differential allergenicity of heated and baked egg might be exploited to prevent or treat egg allergy. In this review, we therefore discuss (i) why some patients are able to tolerate heated egg; by highlighting the structural changes of egg white (EW) proteins upon heating and their impact on immunoreactivity, as well as patient characteristics, and (ii) to what extent heated or baked EW might be useful for primary prevention strategies or oral immunotherapy. We describe that the level of immunoreactivity towards EW helps to discriminate patients tolerant or reactive to heated or baked egg. Furthermore, the use of heated or baked egg seems effective in primary prevention strategies and might limit adverse reactions. Oral immunotherapy is a promising treatment strategy, but it can sometimes cause significant adverse events. The use of heated or baked egg might limit these, but current literature is insufficient to conclude about its efficacy.
Scope
Food allergies result from a complex immune response involving both innate and adaptive immune cells. Major proteins of wheat flour, gliadins, appear to be important allergens, and their ...characteristics can influence the allergic response. This study investigates the immune reaction when developing a food allergy to gliadins in native, deamidated, or hydrolyzed forms.
Methods
The immune response after one or two intraperitoneal sensitizations and after oral challenge with each gliadin form is analyzed.
Results
Results demonstrate that deamidated gliadins induce a stronger allergic reaction compared to native gliadins. Moreover, deamidation induces an earlier increase in intestinal permeability associated with more pronounced Th2 and Th17 polarizations together with an influx of antigen‐presenting cells, especially cDC2.
Conclusion
Altogether, Results indicate that industrial processes such as deamidation or hydrolysis influences food allergenicity through immune modulation and helps us to develop tools to determine how these processes can influence this reaction and encourage or decrease allergic reactions.
Major proteins of wheat flour, gliadins, are important allergens and their characteristics can influence the allergic response. The immune reaction when developing a food allergy to gliadins under different form is investigated. Results demonstrate that deamidation worsens the allergic reaction, whereas hydrolyzation displays a minor effect.
We recently reported that offspring of mice treated during pregnancy with the microbial-derived immunomodulator OM-85 manifest striking resistance to allergic airways inflammation, and localized the ...potential treatment target to fetal conventional dendritic cell (cDC) progenitors. Here, we profile maternal OM-85 treatment-associated transcriptomic signatures in fetal bone marrow, and identify a series of immunometabolic pathways which provide essential metabolites for accelerated myelopoiesis. Additionally, the cDC progenitor compartment displayed treatment-associated activation of the XBP1-ERN1 signalling axis which has been shown to be crucial for tissue survival of cDC, particularly within the lungs. Our forerunner studies indicate uniquely rapid turnover of airway mucosal cDCs at baseline, with further large-scale upregulation of population dynamics during aeroallergen and/or pathogen challenge. We suggest that enhanced capacity for XBP1-ERN1-dependent cDC survival within the airway mucosal tissue microenvironment may be a crucial element of OM-85-mediated transplacental innate immune training which results in postnatal resistance to airway inflammatory disease.
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