Intestinal Microsporidiosis in Diarrheal Patients: " Immunological and Hepatic Profile, and Evaluation of a Novel Food Color Diagnostic Stain"

Intestinal Microsporidia are fungal parasites associated with diarrhea and intestinal disorders in humans, they can invade intestinal cells and proliferate intracellularly, potentially inducing inflammatory and immune responses. This study aimed to detect Microsporidia infection and evaluate selected inflammatory, immunological, and hepatic parameters in patients with diarrhea. A total of 120 stool and blood samples were collected from patients with diarrhea, including 54 males and 66 females, in addition to 43 samples from healthy individuals, during the period from September 2025 to March 2026. Microsporidia infection was diagnosed using Modified Ziehl–Neelsen staining, which identified 30 cases of only Microsporidia infection and 17 cases of mixed infections with Entamoeba histolytica, Giardia lamblia, and Cryptosporidium. Most infections were observed among individuals older than 40 years. A red food coloring stain was also evaluated as an alternative to carbol fuchsin in modified Ziehl Neelsen staining and effectively stained Microsporidia spores. Fecal calprotectin and lactoferrin were positive in both the only Microsporidia and mixed infection groups. White blood cell and neutrophil counts were significantly higher in infected groups than in controls (P ≤ 0.0001). Immunological parameters showed increased levels of secretory immunoglobulin A, interleukin-10, and tumor necrosis factor-alpha in infected groups. Furthermore, aspartate aminotransferase and alanine aminotransferase levels were significantly elevated compared with controls, with no significant differences among infected groups. In conclusion, Microsporidia infection contributes to inflammatory, immunological, and hepatic changes, which were more pronounced in mixed infections. Red food coloring stain also showed potential as a simple, alternative for detecting Microsporidia spores.