Bifidobacterium animalis subsp. lactis BB-12 attenuates diabetic retinopathy through gut microbiota modulation: evidence for the gut– retinal axis

Jiayi Lin¹Yaqi Cheng¹Yumin Ling²Simin Gu¹Haocheng Zhu¹Meng Li¹Huan Yu²Jianbing Li¹Qian Luo¹Weihua Li^2*Shiqi Ling^1*

• ¹Department of Ophthalmology, The Third Affiliated Hospital of Sun Yat-sen University, Sun Yat-sen University, Guangzhou, China
• ²State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-sen University, Guangzhou, China

Purpose: Previous studies have shown that Bifidobacterium animalis subsp. lactis BB-12 plays a role in maintaining the intestinal barrier and regulating inflammation; however, its potential connection to ocular diseases has not been thoroughly explored. Diabetic retinopathy (DR) is a common ocular complication of diabetes and is closely associated with metabolic dysregulation. This study investigated whether BB-12 supplementation could affect systemic diabetic symptoms, the progression of DR, and the stability of gut microbiota. Materials and methods: Diabetic db/db mice were utilized to monitor metabolic parameters, assess hepatic and lipid profiles, evaluate retinal function via ERG, and examine retinal morphology through OCT and HE staining. Treg/Th17 balance was analyzed by flow cytometry, and gut microbiota composition was profiled using 16S rRNA sequencing. Results: The results showed that BB-12 reduced obesity, decreased hepatic steatosis, improved retinal blood vessel health and vision, and influenced both the Treg/Th17 balance and gut dysbiosis in diabetic mice. Conclusions: These findings lay the groundwork for regulatory role of intestinal microbiota on systemic and ocular complications of diabetes, and further examination of the gut-retina axis.