Increased Gut Microbiota Diversity in Patients With Retinitis Pigmentosa and Implications for Disease Phenotypes and Progression

Purpose: Inflammation is often present in retinitis pigmentosa (RP) and is reported to affect visual outcome. Gut microbiota plays a crucial role in inflammatory diseases. This study aimed to elucidate the relationship between the gut microbiota and RP. Methods: The 16S rRNA gene sequencing analysis was performed on stool samples collected from 103 patients with RP and 64 healthy individuals. The α and β diversities of gut microbiota, along with relative abundances, were compared between patients and healthy individuals, as well as between patients with or without cystoid macular edema (CME). The RP model rd10 mice were treated with or without antibiotics starting at 7 days of age. Retinal structure and function were evaluated. Results: Gut microbiota diversity was higher in patients with RP than in healthy individuals (P < 0.001). Moreover, patients with CME had greater diversity than did those without CME and showed a higher abundance of Romboutsia and Ruminococcus (P < 0.05). Antibiotics-treated rd10 mice showed suppressed apoptosis, attenuated decrease of photoreceptors, and a significantly lower incidence of retinal detachment. Retinal function was significantly preserved in mice treated with antibiotics. In antibiotics-treated mice, the expression of Il-1β, Nlrp3, Caspase-1, pNFkb, pJNK, and pCREB1 was downregulated, suggesting suppression of the NLRP3 inflammasome. Conclusions: Patients with RP exhibited distinct gut microbiota characteristics compared to that of healthy individuals. Treatment with antibiotics attenuated disease progression in the RP model mouse. Modifying the gut microbiota may be a potential therapeutic strategy for modifying disease progression in RP in future investigations.