**8. Probiotics in allergic rhinitis**

On these bases, probiotic bacteria are capable of altering immune responses through a range of mechanisms that could minimize allergic reactions to airborne allergens without the side effects of any current drugs, and these possible mechanisms, as shown in **Figure 1**, include regulatory T cells that dampen immune responses and suppress the production of IgE antibodies [92, 93]. There are contradictory studies about the effectiveness of probiotics in treating allergic rhinitis [94]. It is reported that *L. casei* decreased the number of episodes of rhinitis in 64 preschoolers with allergic rhinitis [95]. Nonetheless, another study found that patients treated with *Lactobacillus* GG during the birch pollen season who were allergic to birch pollen and apple food found no improvement in symptom score and no reduced sensitivity to birch pollen and apple following probiotic supplementation [96]. Probiotic consumption increased life performance in allergic rhinitis patients. Blood or immunological parameters did not alter significantly in the probiotic community. This indicates probiotics may be useful in allergic rhinitis, but the data present are not sufficient to make any guidelines for treatment [97, 98].

**Figure 1.**

*Probiotic mechanism against the allergen include increasing regulatory T cells that damp down immune responses and suppress the production of IgE.*

### **9. Probiotics in food allergy**

Food allergy (FA) is one of the pediatric age's most common allergic disorders and has been considered a global health issue, particularly in the developed world.

Naturally, many subjects with FA outgrow this over time. Cow's milk allergy (CMA), hen's egg allergy, and wheat allergy resolve by 5–10 years in 50% of children. Many FAs (including peanuts, tree nuts, and fish) have low-resolution levels and are seen as persistent [99]. Furthermore, certain types of FA may be correlated with the subsequent development of other allergic symptoms such as oculorhinitis, atopic dermatitis, asthma, and urticaria (the so-called "Atopic March") [100] as well as other diseases such as functional gastrointestinal disorders (FGIDs), inflammatory intestinal diseases (IBD) [101], and psychiatric disorders such as attentive autistic spectrum disorders (ASD).

The gut microbiome-immune system axis that influences the frequency of FA may be modulated by several genetic, environmental, and dietary factors [102]. For example, increased family size, pet and/or rural exposure, balanced diet (full of fibers, fermented foods, antioxidants, omega-3), breastfeeding, and probiotic use are correlated with FA safety. Conversely, C-section, prenatal, and early-life exposure to antibiotics/gastric acid inhibitors/antiseptic agents, unhealthy diet (low fibers/high saturated fats, and junk foods) may increase the risk of developing FA. All these environmental factors mainly operate on a modulation of the structure and function of the gut microbiota, which may in effect be responsible for the epigenetic control of genes involved in immune tolerance.

The pathogenesis of these incidents also is largely unknown, but increasing evidence suggests the hypothesis that disturbance of intestinal microbiome, leading to alterations in the immune system and gut-brain axis, may affect the occurrence of FA and FA-related conditions later in life [103] (**Figure 2**).

**145**

**10. Conclusion**

**Figure 2.**

*Probiotic Bacteria in Microbiome against Allergy DOI: http://dx.doi.org/10.5772/intechopen.93385*

Mediterranean diet (MD) is described as a healthy, balanced diet. It is associated with a high intake of assorted cereals, legumes, fruit, vegetables, olive oil, and nuts; moderate consumption of red wine, poultry, and fish; and a lower intake of red meat and sweets. MD has been shown to have a protective role against allergic

Elevated adherence to MD was associated with increased levels of Prevotella and other Firmicutes and production of short-chain fatty acids (SCFAs) [102]. One of the strongest links between diet, gut microbiome, and allergic diseases is the immunomodulatory mechanisms elicited by SCFAs [105]. Common SCFAs contain acetate, butyrate, propionate, and valerate. SCFA-producing bacteria include *Faecalibacterium prausnitzii* and *Eubacterium rectale*. Roseburia is an important butyrate producer [106]. SCFAs are a major source of energy for colonocytes and epigenetically influence many nonimmune functions (tightened junction proteins, and mucus production) and immune functions (macrophages, neutrophils, dendritic cells (DCs), and T and B cells) [107, 108]. Enterocyte interaction of SCFAs is mediated by G-protein-coupled receptors, namely GPCRs, GPR41, GPR43, GPR109A, and Olfr78 [109, 110]. The hopeful target of novel therapeutic and preventive approaches against FA may be the gut microbiome. The results of the studies are promising, but more research is needed for the better definition of the potential for diet-gut microbiome—immune system axis modulation to counter FA. We are entering a new age in which the production and function of the immune system can be controlled by dietary intervention, and the clinical effect can be assessed by gut microbes and their metabolites. Given the current gaps in research methods and data analysis and interpretation, more scientific evidence is required which can be

The results of many studies have demonstrated that there is a strong relationship between modifications within the microbiome and many diseases. Much evidence proves that healthy microbiota affects and improves the immune system. It seems that probiotics can have an important role in the prevention of many diseases such as allergy. Microbiota diversity exists between allergic and nonallergic persons. Different mechanisms are considered for the anti-allergic impact of probiotics, like detecting related molecular patterns, including DNA motifs or LPS of the bacteria

illnesses in children during pregnancy and early life [104].

*Good microbiome as a target for food allergy intervention.*

converted into clinical evidence praxis [103].

*Probiotic Bacteria in Microbiome against Allergy DOI: http://dx.doi.org/10.5772/intechopen.93385*

*Human Microbiome*

**9. Probiotics in food allergy**

*responses and suppress the production of IgE.*

autistic spectrum disorders (ASD).

epigenetic control of genes involved in immune tolerance.

of FA and FA-related conditions later in life [103] (**Figure 2**).

world.

**Figure 1.**

Food allergy (FA) is one of the pediatric age's most common allergic disorders

Naturally, many subjects with FA outgrow this over time. Cow's milk allergy (CMA), hen's egg allergy, and wheat allergy resolve by 5–10 years in 50% of children. Many FAs (including peanuts, tree nuts, and fish) have low-resolution levels and are seen as persistent [99]. Furthermore, certain types of FA may be correlated with the subsequent development of other allergic symptoms such as oculorhinitis, atopic dermatitis, asthma, and urticaria (the so-called "Atopic March") [100] as well as other diseases such as functional gastrointestinal disorders (FGIDs), inflammatory intestinal diseases (IBD) [101], and psychiatric disorders such as attentive

The gut microbiome-immune system axis that influences the frequency of FA may be modulated by several genetic, environmental, and dietary factors [102]. For example, increased family size, pet and/or rural exposure, balanced diet (full of fibers, fermented foods, antioxidants, omega-3), breastfeeding, and probiotic use are correlated with FA safety. Conversely, C-section, prenatal, and early-life exposure to antibiotics/gastric acid inhibitors/antiseptic agents, unhealthy diet (low fibers/high saturated fats, and junk foods) may increase the risk of developing FA. All these environmental factors mainly operate on a modulation of the structure and function of the gut microbiota, which may in effect be responsible for the

The pathogenesis of these incidents also is largely unknown, but increasing evidence suggests the hypothesis that disturbance of intestinal microbiome, leading to alterations in the immune system and gut-brain axis, may affect the occurrence

and has been considered a global health issue, particularly in the developed

*Probiotic mechanism against the allergen include increasing regulatory T cells that damp down immune* 

**144**

**Figure 2.** *Good microbiome as a target for food allergy intervention.*

Mediterranean diet (MD) is described as a healthy, balanced diet. It is associated with a high intake of assorted cereals, legumes, fruit, vegetables, olive oil, and nuts; moderate consumption of red wine, poultry, and fish; and a lower intake of red meat and sweets. MD has been shown to have a protective role against allergic illnesses in children during pregnancy and early life [104].

Elevated adherence to MD was associated with increased levels of Prevotella and other Firmicutes and production of short-chain fatty acids (SCFAs) [102]. One of the strongest links between diet, gut microbiome, and allergic diseases is the immunomodulatory mechanisms elicited by SCFAs [105]. Common SCFAs contain acetate, butyrate, propionate, and valerate. SCFA-producing bacteria include *Faecalibacterium prausnitzii* and *Eubacterium rectale*. Roseburia is an important butyrate producer [106]. SCFAs are a major source of energy for colonocytes and epigenetically influence many nonimmune functions (tightened junction proteins, and mucus production) and immune functions (macrophages, neutrophils, dendritic cells (DCs), and T and B cells) [107, 108]. Enterocyte interaction of SCFAs is mediated by G-protein-coupled receptors, namely GPCRs, GPR41, GPR43, GPR109A, and Olfr78 [109, 110]. The hopeful target of novel therapeutic and preventive approaches against FA may be the gut microbiome. The results of the studies are promising, but more research is needed for the better definition of the potential for diet-gut microbiome—immune system axis modulation to counter FA. We are entering a new age in which the production and function of the immune system can be controlled by dietary intervention, and the clinical effect can be assessed by gut microbes and their metabolites. Given the current gaps in research methods and data analysis and interpretation, more scientific evidence is required which can be converted into clinical evidence praxis [103].

## **10. Conclusion**

The results of many studies have demonstrated that there is a strong relationship between modifications within the microbiome and many diseases. Much evidence proves that healthy microbiota affects and improves the immune system. It seems that probiotics can have an important role in the prevention of many diseases such as allergy. Microbiota diversity exists between allergic and nonallergic persons. Different mechanisms are considered for the anti-allergic impact of probiotics, like detecting related molecular patterns, including DNA motifs or LPS of the bacteria

by Toll-like receptors. Probiotic mechanism against the allergen includes increasing regulatory T cells that damp down immune responses and suppress the production of IgE.
