Diversity of Microbial Signatures in Asthmatic Airways

Abstract

Asthma is a chronic inflammatory disease affecting the respiratory system. The global incidence of asthma is rising. Clinical and experimental models of asthma clearly indicate that the disease is multifactorial in nature with a wide array of factors contributing to progression and exacerbation, including interactions between immunological markers and the microbial community populating the respiratory tract. In particular, strict hygiene compliance during the early years of life and early exposure to antibiotics are linked to alterations in the biological environment within the airways and to changes in immunological markers, leading to allergies, such as asthma. With the gap in current research knowledge on the various non-bacterial microbial communities in the asthmatic airways, this review summarizes current methods used to assess microbial diversity as well as evidence for the link between microbial alterations and asthma, including changes in the bacterial microbiome, often characterized by the outgrowth of certain bacterial phyla such as proteobacteria and Firmicutes, in addition to disrupted mycobiome, virome, and parasitome. The current review emphasizes the dynamic, context-dependent changes in the microbiome in asthma and the importance of broad-scope analyses, covering a wide range of taxa. In conclusion, the interaction between the resident microbiota and the immune system is essential and significant in modulating the inflammatory responses; however, further investigations are needed to improve our understanding of the risk factors that disrupt the diversity of the microbiome in the different body systems.

Mucoadhesive, Antibacterial, and Reductive Nanogels as a Mucolytic Agent for Efficient Nebulized Therapy to Combat Allergic Asthma

“…A defective mucociliary clearance will lead to colonization of certain pathogenic bacteria, and the produced toxins and metabolites will induce inflammatory reaction and thus exacerbate asthma. It is reported that certain bacteria such as Haemophilus , Neisseria , Streptococcus , and Staphylococcus are in a higher abundance in asthmatic airways. − Therefore, it is of great importance to combat bacteria growth for treatment of asthma. Since S. aureus is one of the pathogens that will exacerbate asthma, we studied the antibacterial activity of the CAT nanogels against S. aureus .…”

Microbiome and Asthma: Microbial Dysbiosis and the Origins, Phenotypes, Persistence, and Severity of Asthma

“…Microbiome study can be performed by means of samples from the upper (nose, nasopharynges, oropharynges and saliva) and lower (sputum, bronchial aspiration or bronchoalveolar lavage) airway, with the latter being the most difficult to obtain in the paediatric population. In this case, studying both is relevant [ 13 , 47 ].…”

“…We currently know that the airway is colonised by niche-specific bacterial communities, with a density up to 10 3 –10 4 times lower in the lower airway with respect to the upper airway, and as with the gut microbiome, its colonisation also begins at birth and becomes stable in the first years of life [ 12 , 47 ].…”

Complex Role of Microbiome in Pancreatic Tumorigenesis: Potential Therapeutic Implications

“…The differences in study sizes, designs, sampling methods and primers used for 16S rRNA amplification make interpretation and generalization difficult. Moreover, the decrease in gut microbial diversity in cancer patients compared to healthy individuals, along with the differences in oro-intestinal microbiome between pancreatitis and pancreatic cancer, makes the conclusions on cancer-specific microbiome difficult [ 32 , 33 , 34 , 35 ].…”