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Current Allergy and Asthma Reports Mar 2019The infant gut microbiota has become a focus of multiple epidemiologic and cohort studies. This microbiome is derived from the mother (via the vaginal canal, maternal... (Review)
Review
PURPOSE OF REVIEW
The infant gut microbiota has become a focus of multiple epidemiologic and cohort studies. This microbiome is derived from the mother (via the vaginal canal, maternal skin contact, breastfeeding, and possibly in utero microbial transfer) and is likely influenced by multiple external factors. It is now believed by some experts that colonization and formation of the newborn and alterations of gut microbiota in children are dependent on earlier alterations of the microbiota of mothers during or perhaps even before pregnancy. This review will focus on specific factors (pet keeping, breastfeeding, antibiotic use, and mode of delivery) that influence the infant gut microbiome and atopy.
RECENT FINDINGS
This is a review of recent literature describing how pet keeping, breastfeeding, antibiotic use, and mode of delivery influences and changes the infant gut microbiome and atopy. General trends in gut microbiota differences have emerged in different birth cohorts when each external factor is analyzed, but consistency between studies is difficult to replicate. The aforementioned factors do not seem to confer an overwhelming risk for development of atopy alone. This review provides a comprehensive review of early life environmental factors and their influence on the infant gut microbiome and atopy.
Topics: Animals; Anti-Bacterial Agents; Breast Feeding; Child; Delivery, Obstetric; Female; Gastrointestinal Microbiome; Humans; Infant; Infant, Newborn; Pets; Pregnancy; Prenatal Exposure Delayed Effects
PubMed: 30859338
DOI: 10.1007/s11882-019-0851-9 -
Clinical Reviews in Allergy & Immunology Dec 2019Atopy and fungi have a long associative history. Fungal spores were among the first substances to which humans were noted to be sensitized. Humans contact fungal spores... (Review)
Review
Atopy and fungi have a long associative history. Fungal spores were among the first substances to which humans were noted to be sensitized. Humans contact fungal spores in the outdoor, indoor, and occupational environments. As organisms, fungi have their own kingdom and are found in all environmental niches on earth. Currently, fungal exposure in the indoor environment especially related to wet housing conditions is of particular concern. Sensitization rates to fungi typically exceed 5% of the general public with higher rates among the atopic population. Alternaria is the best studied of the allergic fungi; however, cross sensitization to multiple fungi is well documented. Recent advances in understanding mechanisms of the innate immune system are beginning to explain why the fungal atopy relationship is unique and why fungal sensitivity seems to extend to many non-atopic individuals. Evidence has been accumulated that indicates fungal allergen exposure can be via intact spores as well as spore and mycelial fragments. Germinating spores produce a different and often increased allergen picture. Much evidence has been developed through animal studies that extends the mechanisms surrounding long-term low-level fungal exposure. However, it should be emphasized that the presence of fungi in the air does not necessarily equate with illness. Indeed, in the absence of an atopic individual and/or a significant immune response against fungi, there is little evidence suggesting pathology. Allergists frequently deal with patients who have concerns about indoor fungal exposure and respiratory disease in those patients with an allergic response.
Topics: Allergens; Animals; Antigens, Fungal; Disease Susceptibility; Environmental Exposure; Fungi; Host-Pathogen Interactions; Humans; Hypersensitivity, Immediate
PubMed: 31321665
DOI: 10.1007/s12016-019-08750-z -
Nature Medicine Oct 2016Gut microbiota bacterial depletions and altered metabolic activity at 3 months are implicated in childhood atopy and asthma. We hypothesized that compositionally...
Gut microbiota bacterial depletions and altered metabolic activity at 3 months are implicated in childhood atopy and asthma. We hypothesized that compositionally distinct human neonatal gut microbiota (NGM) exist, and are differentially related to relative risk (RR) of childhood atopy and asthma. Using stool samples (n = 298; aged 1-11 months) from a US birth cohort and 16S rRNA sequencing, neonates (median age, 35 d) were divisible into three microbiota composition states (NGM1-3). Each incurred a substantially different RR for multisensitized atopy at age 2 years and doctor-diagnosed asthma at age 4 years. The highest risk group, labeled NGM3, showed lower relative abundance of certain bacteria (for example, Bifidobacterium, Akkermansia and Faecalibacterium), higher relative abundance of particular fungi (Candida and Rhodotorula) and a distinct fecal metabolome enriched for pro-inflammatory metabolites. Ex vivo culture of human adult peripheral T cells with sterile fecal water from NGM3 subjects increased the proportion of CD4 cells producing interleukin (IL)-4 and reduced the relative abundance of CD4CD25FOXP3 cells. 12,13-DiHOME, enriched in NGM3 versus lower-risk NGM states, recapitulated the effect of NGM3 fecal water on relative CD4CD25FOXP3 cell abundance. These findings suggest that neonatal gut microbiome dysbiosis might promote CD4 T cell dysfunction associated with childhood atopy.
Topics: Asthma; Bifidobacterium; CD4-Positive T-Lymphocytes; Candida; Cell Differentiation; Child, Preschool; Faecalibacterium; Feces; Female; Forkhead Transcription Factors; Gastrointestinal Microbiome; Humans; Hypersensitivity; Infant; Infant, Newborn; Interleukin-2 Receptor alpha Subunit; Interleukin-4; Male; Odds Ratio; RNA, Ribosomal, 16S; Rhodotorula; Sequence Analysis, RNA; T-Lymphocytes
PubMed: 27618652
DOI: 10.1038/nm.4176 -
Clinical and Experimental Allergy :... Jan 2015The prevalence of obesity has increased worldwide, and weight gain has been shown to influence the development and clinical expression of various conditions including... (Review)
Review
The prevalence of obesity has increased worldwide, and weight gain has been shown to influence the development and clinical expression of various conditions including asthma. The relationships between atopy and obesity remain uncertain, both in adults and in children. Although there are physiopathologic mechanisms which could explain how obesity could influence the immune system and promote the process of sensitization, evidences in favour of a possible role of obesity on the development of atopy have been inconsistent. Furthermore, the bulk of evidence suggests that atopy does not mediate the relationship between obesity and asthma, although in some populations, particularly in children and women, such association has been reported. Such lack of relationship has also been found with rhinoconjunctivitis although it has been observed for atopic dermatitis. Several factors may explain these variable results, including populational or environmental characteristics, socioeconomic status, confounding factors, in addition to sample size, and methodology of the performed studies. The possibility that obesity influences atopy through its effects on sex hormones is suggested by a more frequent link between atopy and obesity in women, particularly postpuberal. Further research should be conducted on the influence of weight gain on atopy and atopic diseases.
Topics: Adolescent; Adult; Animals; Asthma; Child; Child, Preschool; Conjunctivitis; Dermatitis, Atopic; Female; Humans; Male; Obesity; Rhinitis; Sex Characteristics
PubMed: 25323112
DOI: 10.1111/cea.12435 -
The Journal of Allergy and Clinical... Feb 2022
Topics: Anti-Asthmatic Agents; Asthma; COVID-19; Glucocorticoids; Humans; Nasopharynx; SARS-CoV-2; Severity of Illness Index; Survival Analysis
PubMed: 34942236
DOI: 10.1016/j.jaci.2021.12.762 -
Life (Basel, Switzerland) Jun 2023Keratoconus is a disease of the cornea that results in progressive steepening and thinning of the cornea and subsequent vision loss. It nearly always presents as a... (Review)
Review
Keratoconus is a disease of the cornea that results in progressive steepening and thinning of the cornea and subsequent vision loss. It nearly always presents as a bilateral disease, suggesting that there is an underlying abnormality of the corneas that becomes manifest with time. However, the mechanisms underlying the development of keratoconus are largely unknown. Associations reported between keratoconus and systemic diseases are abundant in the literature, and the list of possible associations is very long. We found that atopy, Down syndrome, and various connective tissue diseases were the most frequently cited associations in our broad literature search. Additionally, Diabetes Mellitus has been increasingly studied as a possible protective factor against keratoconus. In this review, we have summarized the evidence for and against these particular systemic conditions and keratoconus and have discussed some of the implications of keratoconus patients having these conditions.
PubMed: 37374145
DOI: 10.3390/life13061363 -
The Pan African Medical Journal 2019Keratosis pilaris is characterized by small bumps around hair follicles. Keratosis pilaris simplex results in gray and keratotic papules mainly on the arms, thighs and...
Keratosis pilaris is characterized by small bumps around hair follicles. Keratosis pilaris simplex results in gray and keratotic papules mainly on the arms, thighs and buttocks. It mainly affects women. Keratosis pilaris rubra often results in keratosis pilaris atrophicans. Common variants of keratosis pilaris include: ulerythema ophryogenes, atrophoderma vermiculata, Siemens alopecia. Keratosis pilaris is a genetic disorder and can occur in association with other hereditary diseases such as Noonan syndrome or vitamin disorders. Treatment is mainly based on emollients and keratolytics, but they have only a suspensive effect. We report the case of a 30 year old woman with a personal and family history of atopy, presenting with diffuse keratotic papules on the trunk. The remainder of the physical examination revealed no genetic abnormality. Treatment was based on emollients and keratolytics with slight improvement.
PubMed: 31692799
DOI: 10.11604/pamj.2019.33.274.16158 -
Annales de Dermatologie Et de... Nov 2020Atopy is defined by the propensity to develop an exaggerated type-2 inflammatory response to environmental molecules. Clinically, atopy is diagnosed when atopic disease...
Atopy is defined by the propensity to develop an exaggerated type-2 inflammatory response to environmental molecules. Clinically, atopy is diagnosed when atopic disease occurs: atopic dermatitis, food allergy, atopic asthma and allergic rhinitis and conjunctivitis. Whereas the classical "atopic march" is increasingly challenged through epidemiological studies, type-2 cellular inflammation is a characteristic shared by the atopic diseases. This inflammation can be innate (non-specific: eosinophils, mast cells, dendritic cells, innate lymphoid cells [ILC]), or adaptive (antigen-specific, involving T cells). Interleukins (IL-)4, 5 and 13 are major actors of type-2 inflammation and are mainly produced by ILC and T cells. The efficacy of treatments targeting these type-2 cytokines highlight the importance of type-2 inflammation in atopic diseases. However, several patients do not respond to type-2 targeting treatments, highlighting the presence of other actors in pathophysiology of atopic diseases: alteration of epithelial barrier, IgE-mediated allergic responses, type-17 inflammation. Thus, the term "endotype" can illustrate this diversity in pathophysiology. Finally, a global approach of atopic diseases, as type-2 inflammatory diseases, is fundamental, but not sufficient. An approach by endotype is advisable, in a personalized medicine perspective. © 2020 Elsevier Masson SAS. All rights reserved.
Topics: Dermatitis, Atopic; Eczema; Food Hypersensitivity; Humans; Immunity, Innate; Lymphocytes
PubMed: 33250137
DOI: 10.1016/S0151-9638(20)31082-6 -
Current Opinion in Pediatrics Dec 2018The mechanisms underlying the overlap of, and relationship between, atopy and immunodeficiency are just beginning to be recognized, through the identification of novel... (Review)
Review
PURPOSE OF REVIEW
The mechanisms underlying the overlap of, and relationship between, atopy and immunodeficiency are just beginning to be recognized, through the identification of novel genetic conditions and the reexamination of well known primary immunodeficiencies. The present review seeks both to frame the topic and to highlight the most recent literature combining allergy in the context of immunodeficiency.
RECENT FINDINGS
The true prevalence of atopic disorders in the setting of primary immunodeficiency as a whole is difficult to pinpoint, however there have been recent attempts to measure prevalence. Individual immunodeficiency disorders have been more carefully dissected for atopic disease and the mechanisms underlying the atopic phenotypic, whereas several newly described immune deficiencies because of single gene mutations are highly associated with atopic phenotypes. Finally, a number of novel genetic conditions with atopy being the primary feature, even in the absence of overt immune deficiency, have been described, providing instrumental clues into the diagnostic dilemmas these syndromes create.
SUMMARY
Defining and examining diseases with primary features of atopy and infection allow for a better understanding of the interplay between the two in rare disease, and hopefully sheds light on fundamental pathways involved in atopy and host defense in the general population.
Topics: Child; Genetic Predisposition to Disease; Humans; Hypersensitivity; Immunologic Deficiency Syndromes; Mutation; Prevalence
PubMed: 30407976
DOI: 10.1097/MOP.0000000000000697