Impact of protein malnutrition on histological parameters of experimentally infected animals with Giardia lamblia

► Histological parameters in giardiasis combined with low-protein diet was evaluated. ► Quantification of G. lamblia in mucosa was not significantly affected by diet. ► Villus height was significantly affected by diet. ► Mucus production was significantly affected by diet and infection. ► Malnutrition may contribute to disease severity in Giardiasis.