Why some Indians who never even saw details Soto died after his explorations?

Some Indians who had never seen Hernando de Soto still died after his explorations due to the spread of diseases introduced by Europeans, such as smallpox and influenza, to which they had no immunity. The disruption of local ecosystems and social structures also contributed to food shortages and increased violence among tribes. Additionally, De Soto's expedition led to conflicts and warfare, resulting in casualties among indigenous populations even in areas where they had no direct contact with the explorers.