Obesity exacerbates giardiasis: metabolic, intestinal, and immune response in high-fat diet-fed gerbils

Obesity has emerged as a critical factor influencing host-pathogen interactions and infection outcomes. However, its role in protozoan infections such as giardiasis remains poorly understood. In this study, we investigated the effects of a high-calorie, high-fat diet on metabolic, intestinal, and immune parameters in gerbils infected with Giardia lamblia. Our results demonstrated that the high-fat diet significantly increased body weight and induced metabolic disturbances, including dyslipidemia, hepatic fat accumulation, and altered adipokine production. Moreover, Giardia infection exacerbated these effects, leading to intensified intestinal inflammation and epithelial damage. Notably, obese animals exhibited a compromised immune response to infection, characterized by reduced production of inflammatory cytokines and increased parasitic load after two weeks. These findings indicated that obesity weakened the immune system's ability to control Giardia infection, thereby exacerbating the severity of giardiasis. Additionally, the combination of obesity and infection resulted in morphological alterations in intestinal tissue, further amplifying inflammation and impairing immune responses. Our study underscores the importance of obesity management to mitigate the inflammatory state that worsens infectious diseases, such as giardiasis. This is particularly relevant in vulnerable populations, such as children, who are at higher risk of infection and its associated complications.