Probiotic Supplementation Mitigates Vascular Remodeling in the Retina
Authors: Singh Mahavir , George Akash K , Homme Rubens P , Majumder Avisek , Laha Anwesha , Metreveli Naira , Pushpakumar Sathnur B , Tyagi Suresh C 
Published: June 2021

Human microbiome project has brought tremendous excitement and insights into different aspects of health and disease etiology. Interestingly, a connection between ocular surface microbiota and select eye diseases has already been established however the efficacy of non‐ocular microbiome especially the probiotics in ocular health and diseases still remains to be elucidated. With the availability of latest microbial research tools along with bioinformatics analysis it is now possible to investigate the effects of microbiota and their corresponding metabolites in a host of retinal diseases. It is known that gut dysbiosis results from perturbations in gastro‐intestinal microbial populations and this dysbiosis can potentially affect retinal metabolism/ocular homeostasis. We hypothesize that restoring the gut symbiosis via probiotic supplementation could improve neuro‐retinal functioning and help mitigate vascular remodeling of the retinal architecture in a mouse model (CBS+/−) of hyperhomocysteinemia (HHcy) that is metabolically prone to ocular hypertension including retino‐vascular occlusion. To test our hypothesis we used Lactobacillus rhamnosus GG; a widely used probiotic to investigate its salutary effects on retinal health in CBS+/− mice and compared the results with that of C57BL/6J; wild type (WT) strain. Mice were administered orally Lactobacillus rhamnosus GG @ 2.5×105 CFU once daily for 12 weeks. Experimental groups were designated as: Group‐I: WT + regular chow diet, Group‐II: WT + regular chow diet + Lactobacillus rhamnosus GG, Group‐III: CBS+/− + High Methionine Diet (HMD), and Group‐IV: CBS+/− + HMD + Lactobacillus rhamnosus GG. Angiography in the CBS+/− + HMD mice revealed reduced vascularity and impaired visual functions. These conditions were subsequently improved with Lactobacillus rhamnosus GG supplementation. Further experimentations employing electro‐retinography (ERG) on CBS+/− + HMD + Lactobacillus rhamnosus GG treated group lent support to the observed beneficial effects of the probiotic treatment on visual functions. In addition, Lactobacillus rhamnosus GG administration reduced HHcy‐induced oxidative and ER stress levels in the CBS+/− + HMD mice that were revealed via expression analyses of the key marker proteins in the retinal lysates from the probiotic treated mice group. Taken together, our findings indicate that Lactobacillus rhamnosus GG consumption helped restore retinal dysfunction/metabolism and relieved adverse neuro‐retinal/vascular remodeling phenotype as induced by chronic HHcy environment in the eyes most likely via modulation of the gut microbiota composition through gut‐retina axis.Support or Funding InformationThe work was supported by grants from the National Institute of Health (Heart, Lung, and Blood Institute; No. HL‐74815, HL‐107640) and the Institute of Neurological Disorders and Stroke (No. NS‐084823).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.