The following is a summary of “Comparison of intestinal microbes and metabolites in active VKH versus acute anterior uveitis associated with ankylosing spondylitis,” published in the October 2023 issue of Opthalmology by Li et al.

Gut microbiome involvement in uveitis is known, but specific microbes and metabolites for different uveitis types are unclear. Researchers started a retrospective study to identify the pathogenic microbes and metabolites in Vogt Koyanagi Harada (VKH) and ankylosing spondylitis-associated uveitis.

They assessed the microbiome and metabolites in 45 individuals, which included 16 patients with VKH, 11 patients with acute anterior uveitis (AAU), and 18 healthy controls, using 16S ribosomal DNA and LC-MS/MS (liquid chromatography-tandem mass spectrometry).

The results showed the diversity of intestinal microbes in the VKH, AAU, and control groups did not differ significantly. VKH patients exhibited 13 specific microbes and 38 metabolites, of which 7 had significant changes (P<0.05), impacting nicotinamide and biotin metabolism. In comparison, the AAU group had milder intestinal changes, with 11 specific microbes and 29 metabolites affected (P<0.05), primarily influencing arachidonic acid metabolism. Some changes were common between VKH and AAU, involving three microbes and two metabolites (P<0.05). Notably, specific microbes (Pediococcus, Pseudomonas, Rhodococcus, Photobacterium, Gardnerella, and Lawsonia) and two metabolites (pyrimidine and gallocatechin) effectively distinguished VKH patients from AAU and healthy individuals, with AUC values exceeding 82%. Additionally, four microbes (Lentilactobacillus, Lachnospiraceae_UCG-010, Cetobacterium, Liquorilactobacillus) could differentiate AAU patients from VKH and healthy controls with AUC values over 76%.

They concluded that different gut microbes and metabolites may contribute to varying types of uveitis, primarily via B vitamin metabolism in VKH.

Source: bjo.bmj.com/content/early/2023/10/11/bjo-2023-324125