Background: Digestive tissues are essential for diet processing and nutrient accessibility, especially in omnivores, and these functions occur despite and in collaboration with dynamic microbial communities that reside within and upon these tissues. Prolonged host development and reduced digestive tissue sizes have been observed in germ-free animals, and normal host phenotypes were recovered following the re-introduction of typical gut microbiomes via coprophagy.
Results: High-resolution histological analyses of Periplaneta americana cockroach digestive tissues revealed that total prevention of microbial colonization of the gut had severe impacts on the growth and development of gut tissues, especially the posterior midgut and anterior hindgut subcompartments that are expected to be colonized and inhabited by the greatest number of bacteria.