Mechanisms of impaired glucose transport in cryptosporidiosis in goat kids.

Abstract

BACKGROUND: Cryptosporidium parvum (C. parvum) is a major cause of enteropathies in goat kids, yet the mechanisms underlying glucose malabsorption and transporter dysregulation are not well understood. This study aimed to evaluate the impact of C. parvum infection on glucose transport in enterocytes and to determine whether probiotic therapy could counteract these changes. The study was conducted in 2024 on three goat farms in the Republic of Bashkortostan. Thirty goat kids, aged 3-6 weeks, were enrolled and allocated into three groups (n&#x2009;=&#x2009;10 each): infected without treatment; infected with antiprotozoal therapy; and healthy controls. A morphometric examination of the ileum was conducted alongside quantitative molecular analysis (qPCR), immunological assays (Western blotting and immunohistochemistry), and biochemical measurements. The expression of sodium-glucose cotransporter 1 (SGLT1), glucose transporter 2 (GLUT2), and Na&#x207a;/K&#x207a;-ATPase was assessed. A Glucose Transmembrane Absorption Index (IGT) was calculated using the following formula: IGT = (SGLT1 protein &#xd7; GLUT2 protein &#xd7; Na/K-ATPase protein) / villus height. RESULTS: Infection with C. parvum markedly reduced the expression of both SGLT1 and GLUT2 at mRNA and protein levels (decreases of 2.3- and 2.1-fold, and 2.6- and 2.3-fold, respectively; p&#x2009;<&#x2009;0.0001). Na&#x207a;/K&#x207a;-ATPase protein abundance showed a significant, albeit less pronounced, decline (1.4-fold; p&#x2009;<&#x2009;0.05). Significant villus atrophy (a 38% reduction; p&#x2009;<&#x2009;0.0001), crypt hyperplasia, and a&#x2009;>&#x2009;2.5-fold decrease in the villus-to-crypt ratio were observed. IGT decreased by more than twofold (p&#x2009;<&#x2009;0.0001) and was accompanied by a 2.4-fold increase in luminal glucose concentration (p&#x2009;<&#x2009;0.0001), elevated lactate, and increased ketone bodies. Antiprotozoal therapy led to a partial improvement in morphometric and molecular parameters (p&#x2009;<&#x2009;0.05 vs. untreated animals), but did not normalise them completely. CONCLUSIONS: C. parvum infection in goat kids results in impaired glucose absorption due to morphological and transporter-mediated disturbances. The proposed IGT index reflects these multifactorial disturbances and could be used as an integrative marker of mucosal function, although it requires further validation. The therapeutic intervention provided only partial restoration, highlighting the need for broader, longer-term approaches. These findings improve our understanding of the mechanisms underlying glucose malabsorption in caprine cryptosporidiosis.