Relationship between nasopharyngeal microbiota and patient’s susceptibility to viral infection

Abstract

Introduction: The burden of respiratory viral infections is a global public health concern with significant mortality, morbidity, and economic impact. While Koch's postulate led to considering only the etiological agent, numerous works have demonstrated that commensal microbes could contribute to both the susceptibility and the severity of these infections, in particular those of the nasopharynx. Areas covered: Herein, we first propose to briefly recall the historical background that led to considering microbes inhabiting the nasopharyngeal microbiota as a potential contributor to human viral infections. We describe the evolution of the normal nasopharyngeal microbiota composition over time, especially during the first year of life. We aimed to resume the changes of the nasopharyngeal microbiota during viral respiratory infections. We also develop how nasopharyngeal microbiota could contribute to the acquisition of respiratory viral infections. We finally provide the potential therapeutic perspectives deriving from these findings. Expert opinion: Prospective studies focusing on children have identified that nasopharyngeal microbiota composition is associated with predisposition to acute respiratory illness and bronchiolitis, while data are scarce regarding adults. For the latter, further works are needed, in particular as a part of the multi-OMICS approach that should probably be performed in conjunction with gut microbiota studies.

Strengthening the Immune System and Reducing Inflammation and Oxidative Stress through Diet and Nutrition: Considerations during the COVID-19 Crisis

“…It is important to highlight the emerging role of the microbiota, its modulation by nutrition, and its influence on responses to viral infection, though human studies linking diet, gut microbiota, and infection are scarce. While mainly the gut-microbiota has been studied in relation to the immune system, the nasopharyngeal microbiota may be involved in the etiology of respiratory infections [ 186 ]. An interplay between respiratory tract infections and the gut microbiota has been emphasized.…”

Respiratory syncytial virus and airway microbiota -- A complex interplay and its reflection on morbidity

“…Antibiotic treatments were associated with higher abundances of the potential respiratory pathogens Haemophilus , Streptococcus andMoraxella , with lower abundances of Alloiococcus andCorynebacterium (figure 1C) [13]. This microbial dysbiosis may predict subsequent respiratory infections [2,[15][16][17]. Colonization with Streptococcus , Moraxella orHaemophilus spp was linked to an increased risk for LRTI, whilst nasopharyngeal microbiota dominated by Corynebacterium orAlloiococcus clusters was associated with less respiratory morbidity (figure 1D) [11][12][13].…”

The intersect of genetics, environment, and microbiota in asthma—perspectives and challenges

“…112 This suggests that interactions and mechanisms may differ by age groups. In addition, there may be possible interaction between bacterial and viral respiratory pathogens-superinfection by pathogenic bacteria such as Haemophilus, Streptococcus, and Moraxella increases the symptomatic severity of viral illnesses, 113,114 and there is also some evidence of events in the opposite direction: that increasing M catarrhalis colonization can actually precede viral respiratory infections in infants. 96 Ultimately, the details of the biological mechanisms behind these associations require further investigation.…”