ABSTRACT

Purpose: Livestock workers experience an increased burden of bioaerosol-induced respiratory disease. We have previously demonstrated that dairy operations generate bioaerosols spanning the inhalable size fraction. These aerosols contained complex bacterial communities and inflammagens. Because those particles with an aerodynamic diameter between 10 and 100 μm are known to deposit in the nasopharyngeal region, we believe that exposure health outcomes in the upper respiratory tract are important and need consideration, especially in the context of the nasal microbiome (i.e., collection of bacterial communities suggested to play a key role in health and disease).

Methods: We evaluated the effectiveness of a hypertonic saline nasal lavage in reducing inflammatory responses in dairy workers from a high-volume dairy operation. We collected inhalable personal breathing zone (PBZ) samples and pre-/post-shift nasal lavage samples from each participant over five consecutive days. The treatment group (n = 5) received hypertonic saline, while the control group (n = 5) received normotonic saline. PBZ samples were analyzed for particulate concentrations and endotoxin using gravimetric and enzymatic methods, respectively. Pro- and anti-inflammatory cytokines (i.e., IL-8, IL-10, and TNF-α) were measured from nasal lavage samples using a multiplex assay. To measure the air and nasal microbiomes, lavage and dust samples were analyzed using 16S rRNA sequencing.

Results/Findings: Inhalable dust concentrations ranged from 0.15 to 1.9 mg/m³. Significant differences in pro-inflammatory cytokines were observed between treatment and control groups for IL-6. Contrary to the hypothesis, IL-6 concentrations were higher in the treatment group than the control group. However, the treatment group had significantly higher IL-10 (anti-inflammatory) concentrations than the control group. Distinct bacterial communities were observed in pre- and post-shift lavage samples, with post-shift communities more closely resembling those found in dust samples.

Practical Implications: Based on pilot results, the intervention was successful in upregulating anti-inflammatory cytokines and promoting changes in the nasal microbiome. Therefore, more research is warranted to determine if a hypertonic nasal rinse is an effective intervention that does not cause adverse perturbations to the microbiome.

摘要

目的：畜牧工人遭受生物气溶胶引起的呼吸道疾病的负担增加。先前我们已经证明，乳业运营产生的生物气溶胶跨越可吸入颗粒物的一部分。这些气溶胶含有复杂的细菌群落和炎症。因为已知空气动力学直径在10至100μm之间的那些颗粒会沉积在鼻咽区域，所以我们认为在上呼吸道暴露于健康状况非常重要，需要加以考虑，尤其是在鼻腔微生物组的情况下（即收集）的细菌群落在健康和疾病中起关键作用）。

方法：我们评估了高渗盐水鼻腔灌洗在减少大批量乳制品手术中乳制品工人炎症反应方面的有效性。我们连续五天从每位参与者收集了可吸入的个人呼吸区（PBZ）样本和移位前/移位后的鼻灌洗样本。治疗组（n = 5）接受高渗盐水，而对照组（n = 5）接受降冰片盐水。分别使用重量法和酶法分析PBZ样品的颗粒物浓度和内毒素。使用多重测定从鼻灌洗液样品中测量促炎和抗炎细胞因子（即IL-8，IL-10和TNF-α）。为了测量空气和鼻微生物，使用16S rRNA测序分析了灌洗液和灰尘样品。

结果/发现：可吸入粉尘浓度范围为0.15至1.9 mg / m ³。在治疗组和对照组中，IL-6的促炎细胞因子存在显着差异。与该假设相反，治疗组的IL-6浓度高于对照组。但是，治疗组的IL-10（抗炎）浓度明显高于对照组。在轮班前和轮班后的洗手液样本中观察到了明显的细菌群落，而轮班后的群落更类似于粉尘样品中的细菌群落。

实际意义：根据试验结果，该干预成功地上调了抗炎细胞因子并促进了鼻腔微生物组的改变。因此，需要进行更多的研究来确定高渗鼻冲洗液是否是一种不会对微生物组造成不利干扰的有效干预措施。