Urbanization activities, such as eutrophication, pollution and runoff, lead to changes by negatively impacting and reducing the diversity of the microbiome. Urban blue spaces are an integral part of cities; several communities depend on urban water bodies for their livelihood and survival and are heavily affected by rapid urbanization. They play a crucial role in maintaining both human and ecological health at the population level. Quantifying these changes is important for sustainable urban planning.
Using extensive keywords targeting urban blue spaces, such as microbiome and urbanization, we retrieved 1060 papers from two databases and one search engine based on our inclusion criteria of primary data sources for microbiome of aquatic freshwater bodies. Out of 1060, we identified 105 eligible papers after multiple screening rounds. We analyzed these manuscripts from 2000 to 2025 that examined changes in the functional traits, such as antimicrobial resistance (AMR) and nitrogen cycling of the microbiome. Data were extracted by a thematic analysis followed by a narrative synthesis on specific functional traits. This systematic review presents a comprehensive analysis of the changes and challenges caused by urbanization.
Our results indicate that urbanization leads to reduced bacterial diversity of urban water bodies, specifically an increase in Proteobacteria, Cyanobacteria and Coliform bacteria. A significant increase in AMR genes in the water bodies increases the risk of infection by a resistant pathogen.
Microbiome studies on water bodies are indicators for the extent of spread of AMR among pathogens, animals, and humans. The release of antimicrobial compounds into water bodies acts as a driving force for microbial resistance and leads to the emergence of resistant pathogens. Understanding changes in the microbiome is crucial to various blue space functions such as nutrient cycling, organic matter decomposition, and water purification. These insights help inform public health strategies and sustainable urban planning.
