Overnutrition, Nasopharyngeal Pathogenic Bacteria and Proinflammatory Cytokines in Infants with Viral Lower Respiratory Tract Infections

Abstract

Background: Little is known about the interaction between the nasopharyngeal bacterial profile and the nutritional status in children. In this study, our main goal was to evaluate the associations between overnutrition and the presence of four potentially pathogenic bacteria in the nasopharynx of infants with viral lower respiratory tract infections (LRTI). In addition, we determined whether changes in the nasopharyngeal bacterial profile were associated with mucosal and serum proinflammatory cytokines and with clinical disease severity. Methods: We enrolled 116 children less than 2 years old hospitalized for viral LRTI during two consecutive respiratory seasons (May 2016 to August 2017); their nutritional status was assessed, and nasopharyngeal and blood samples were obtained. S. aureus, S. pneumoniae, H. influenzae, M. catarrhalis, and respiratory viruses were identified in nasopharyngeal samples by qPCR. Cytokine concentrations were measured in nasopharyngeal and blood samples. Disease severity was assessed by the length of hospitalization and oxygen therapy. Results: Nasopharyngeal pathogenic bacteria were identified in 96.6% of the enrolled children, and 80% of them tested positive for two or more bacteria. The presence and loads of M. catarrhalis was higher (p = 0.001 and p = 0.022, respectively) in children with overnutrition (n = 47) compared with those with normal weights (n = 69). In addition, the detection of >2 bacteria was more frequent in children with overnutrition compared to those with normal weight (p = 0.02). Multivariate regression models showed that the presence and loads of S. pneumoniae and M. catarrhalis were associated with higher concentrations of IL-6 in plasma and TNF-α in mucosal samples in children with overnutrition. Conclusions: The nasopharyngeal profile of young children with overnutrition was characterized by an over representation of pathogenic bacteria and proinflammatory cytokines.

Cytokines in influenza in children (literature review)

“…[88]. IL-22 является также малоизученным цитокином, но, как считают G. Arias-Bravo et al, он необходим для нормального восстановления легких после инфицирования вирусом гриппа [89].…”

“…У детей с избыточной массой тела в плазме крови и в образцах из носоглотки выявляется более высокая концентрация IL-6 и TNF-α [89]. При выявлении Moraxella catarrhalis у них также обнаруживается увеличение содержания провоспалительных цитокинов, в меньшей степени -при обнаружении Streptococcus pneumoniae [90].…”

Flu in children: Clinical, laboratory indicators and cytokine profile parameters

“…У детей с избыточной массой тела описаны более высокие концентрации IL-6 в плазме крови и TNF-α в образцах носоглоточных смывов [6,7]. У этих детей также более высокая заболеваемость и смертность при гриппе и высокий риск развития вторичных бактериальных инфекций [8].…”

Microbiota Profile of the Nasal Cavity According to Lifestyles in Healthy Adults in Santiago, Chile

“…Some factors studied are diet and stress, physical activity, and smoking habits both in the gut and respiratory microbiota [ 8 , 9 ]. In a recent study, the nasopharyngeal profile of young children with overnutrition was characterized by an over-representation of pathogenic bacteria and proinflammatory cytokines [ 10 ].…”