Distinct microbiota dysbiosis in patients with laryngopharynx reflux disease compared to healthy controls

To compare the differences in the laryngopharynx microbiome between patients with laryngopharyngeal reflux disease (LPRD) and healthy people and further explore the influence of related risk factors pharyngeal microbiome.

This was a case-control study. Patients with a reflux symptom index (RSI) score > 13 or reflux finding score (RFS) score > 7 were diagnosed with suspected LPRD at the Department of Otolaryngology-Head and Neck Surgery of The 900th Hospital of Joint Logistic Support Force. Patients were assessed using a related risk factors questionnaire survey and examined by electronic naso-laryngoscopy. Simultaneously, laryngopharynx secretions were collected from the patients. The patients received at least eight weeks of proton pump inhibitor therapy, and those who responded were enrolled in the final experimental group. In parallel, laryngopharynx secretions were collected from healthy volunteers as the control group, and the laryngopharynx microbiota were analyzed using second-generation high-throughput sequencing.

A total of 23 cases each in the experimental and control group were included in this study. The experimental group microbiota were composed of Streptococcus, Prevotella, Haemophilus, Neisseria, Actinobacillus, Fusobacterium, and Porphyromonas. There was no significant difference in microbial alpha and beta-diversity analysis between the two groups. However, some advantageous bacterium groups were significantly different. The abundance of Prevotella in the experimental group was significantly higher than that of the control group (U = 117, P < 0.05), while the abundance of Fusobacterium (U = 140, P = 0.006) and Porphyromonas (U = 120, P = 0.002) was significantly lower than the control group. Smoking was positively correlated with Pectin (r = 0.46, P = 0.037), Lactobacillus (r = 0.48, P = 0.027), and Clostridium (r = 0.46, P = 0.037), while alcohol was negatively correlated with Streptococcus (r = - 0.5539, P = 0.0092).

The dominant microflora in the laryngopharynx of LPRD patients was significantly different from that of healthy people, suggesting that the change of laryngopharynx microflora may play an important role in the pathogenesis of LPRD. Smoking, drinking, eating habits, and age correlated with different genus levels of the laryngopharynx microbiota.