Atopobiosis and Dysbiosis in Ocular Diseases: Is Fecal Microbiota Transplant and Probiotics a Promising Solution?

Abstract

Purpose: To highlight the role of atopobiosis and dysbiosis in the pathomechanism of autoimmune uveitis, therefore supporting fecal microbiota transplant (FMT) and probiotics as potential targeted-treatment for uveitis.
 Methods: This review synthesized literatures upon the relation between gut microbiota, autoimmune uveitis, FMT, and probiotics, published from January 2001 to March 2021 and indexed in PubMed, Google Scholar, CrossRef.
 Results: The basis of the gut–eye axis revolves around occurrences of molecular mimicry, increase in pro-inflammatory cytokines, gut epithelial barrier disruption, and translocation of microbes to distant sites. In patients with autoimmune uveitis, an increase of gut Fusobacterium and Enterobacterium were found. With current knowledge of aforementioned mechanisms, studies modifying the gut microbiome and restoring the physiologic gut barrier has been the main focus for pathomechanism-based therapy. In mice models, FMT and probiotics targeting repopulation of gut microbiota has shown significant improvement in clinical manifestations of uveitis. Consequently, a better understanding in the homeostasis of gut microbiome along with their role in the gut–eye axis is needed to develop practical targeted treatment.
 Conclusion: Current preliminary studies are promising in establishing a causative gut–eye axis relationship and the possibility of conducting FMT and probiotics as targeted treatment to mitigate autoimmune uveitis, to shorten disease duration, and to prevent further complications.

Conjunctival sac microbiome in anophthalmic patients: Flora diversity and the impact of ocular prosthesis materials

“…The increased of Fusobacterium may cause the disorder of ocular intestinal axis regulation, and lead to the occurrence and disease progression of autoimmune uveitis. Other studies showed that the infection of anaerobic bacteria may aggravate the symptoms of ocular diseases, and the detection of anaerobic bacteria may have the potential to develop into a new generation of diagnostic markers ( Brook, 2001 ; Brook, 2008 ; Gunardi et al., 2021 ). However, compared with healthy subjects, the abundance of Lactobacillus and Lactococcus in OP patients decreased significantly.…”

Composition of the gut microbiome, role of diet, lifestyle, and antioxidant therapies in diabetes mellitus and diabetic retinopathy

“…To date there are no studies investigating the role of FMT in treatment of DR; however, this may be a future avenue of study. 130 Finally, flora is an intermediary for many of the molecules implicated in the pathophysiology of DR and may be an avenue for a new generation of therapeutics. Individualized therapy based on the composition of a patient's microbiome may bridge the gap for patients with medically refractive DR.…”

“…To date there are no studies investigating the role of FMT in treatment of DR; however, this may be a future avenue of study. 130…”

The Gut–Eye Axis: Correlation Between the Gut Microbiota and Autoimmune Dry Eye in Individuals With Sjögren Syndrome

“…41 In addition, the reconstitution of age-associated gut dysbiosis with FMT from young donors improves aging-driven lacrimal gland circadian dysfunction, reduces lipid deposition and chronic inflammation, and modulates neural activity in aging lacrimal glands by regulating the global rhythmic gene (KEGG) expression in aging exorbital lacrimal glands. 43 Probiotics are living microorganisms that confer beneficial effects on the host organism by competing with potential pathogens or gut commensals and can be used as biotherapy to induce tolerance or modification of the immune system, 44,45 in particular, which are crucial to maintain ocular immune homeostasis and regulate autoimmune dry eye. 46 Recent animal studies of dry eye and probiotics have generally observed that antibiotic treatment increases the risk of dry eye, whereas probiotics can provide clinical benefits to dry eye by reducing inflammatory cell production.…”

“…Probiotics are living microorganisms that confer beneficial effects on the host organism by competing with potential pathogens or gut commensals and can be used as biotherapy to induce tolerance or modification of the immune system, 44,45 in particular, which are crucial to maintain ocular immune homeostasis and regulate autoimmune dry eye. 46 Recent animal studies of dry eye and probiotics have generally observed that antibiotic treatment increases the risk of dry eye, whereas probiotics can provide clinical benefits to dry eye by reducing inflammatory cell production.…”