The abundance of administration. house dust mite (HDM)-treated murine models of asthma. Of these, administration was the most effective: it alleviated airway inflammation, decreased total IgE and HDM-IgG1, and reduced Th2-associated pro-inflammatory cytokines. Moreover, modulation of specific microbial genera by was more effective in asthma prevention than the modulation of the overall microbiota composition. and were enriched after supplementation and were closely associated with total IgE and IL-13 production. Furthermore, specifically altered the gut microbial function toward butyrate generation. Thus, may reduce the risk of asthma development by modulating specific gut microbiota to improve the lung immune environment. Our study suggests a novel option for gut microbiome manipulation via supplementation for suppression of asthma and other allergic diseases. Introduction Allergies are immune-mediated disorders primarily caused by an IgE-dependent immunological reaction to an allergen (an innocuous environmental antigen). Depending on the allergen contact site, different clinical HUP2 manifestations, characterized by the presence of IL-4, IL-5, IL-13, and IL-17A and increased levels of IgE and IgG, may occur in the gastrointestinal tract, skin, or airways [1C3]. Asthma is one such allergic disease, and it is defined as an allergen-mediated airway inflammatory disease [4], and among the most common affliction in the world [5]. The currently available treatment options alleviate the symptoms of asthma and other allergic diseases but cannot provide complete cure. Intestinal microbiota is an important stimulatory factor for immune system development and function. The microbiota composition and metabolites in individuals with allergies have been reported to be different from those in healthy individuals [6C8]. Moreover, asthma involves gut microbiome perturbation and is associated with metabolic dysfunction. In mice, manipulation Maropitant of the gut microbiome using oral probiotics or high-fiber dietary supplementation (which increases the synthesis of short-chain fatty acids (SCFA)) facilitates pro-resolving local and remote mucosal immunity [9,10]. Therefore, targeting the gut microbiota with probiotics, prebiotics, and dietary alteration would be a rational therapeutic approach to prevent asthma and other allergic diseases. is one of the most widely known probiotics. Low relative abundance of was reported to be associated with asthma development early in life [11]. GG was shown to be effective in the prevention of asthma in children at high risk [7], whereas supplementation did not ameliorate asthma in infants [13]. Thus, several studies have focused on the effectiveness of in asthma, and supplementation has been reported as an effective preventive strategy for allergy development in experimental and clinical studies. However, the precise species that provide the essential beneficial effect and the underlying gut microbiome-dependent mechanisms remain unclear. Therefore, in this study, Maropitant we investigated the asthma-preventive effects of six species, each constituting five strains. We aimed to assess the effectiveness of against asthma and explore the mechanisms involved to better understand the immunomodulatory and preventive effects of probiotic in allergies. Materials and methods Bacterial strains The study included 30 strains belonging to six species: for 15 min at 4C), washed twice with sterile saline, and stored at ?80C until further use. Each candidate strain was adjusted to 109 CFU. Five strains of the same species were mixed and administered orally to each mouse. The gradient dilution method was used to determine the number of bacterial cells. Table 1 Strains used in animal experiments. species, starting 1 week before the first sensitization and Maropitant continued till the end of the experiment. Allergic airway inflammation was analyzed on week 5 after the last challenge (Fig 1). Open in a separate window Fig 1 House dust mite (HDM) sensitization and exposure protocols.A timeline of HDM immunization Maropitant and exposure and the administration of the six species in the model has been provided. Characterization of the allergic phenotype To characterize the allergic phenotype, the following parameters were analyzed: (a) inflammation score in lung histology, (b) serum immunoglobulin, and (c) cytokines in BALF. Serum immunoglobulin analysis Mouse serum was collected and frozen at ?20C. Serum immunoglobulins were measured using.