Chapter 25 – Dysbiosis

Colonization of the gut with bacteria has a profound effect on intestinal metabolic and immunologic homeostasis, particularly in the newborn period. Disruption of the initial colonization process can result in dysbiosis at a time when intestinal metabolic and immunologic functions are just developing. This dysbiotic change can have profound effect on disease expression throughout life. Dysbiosis, altered bacterial colonization associated with disease expression, can occur with a loss of specific health promoting bacteria, altered bacterial diversity, or with an increase in pathogens in the microbiome. There are several causes of dysbiosis including genetic and environmental (antibiotic use, diet, stress, and chronic disease). In general, dysbiotic bacteria because of altered metabolism can contribute to the phenotypic expression of disease. Whether this is a cause or an effect has yet to be established. A specific species of organisms are associated with disease (either by their presence or absence); new probiotics may emerge to be used to prevent or treat these diseases. However, this represents future studies.