Human and environmental health both face complex challenges, despite living in an era of highly advanced technology. The human microbiota is a master key to maintaining health by performing functions ranging from breaking down and digesting complex compounds, synthesizing essential vitamins, metabolizing xenobiotics, maturing the immune system, and fighting pathogens. Disturbances in the diversity of the human body’s microbiota, often triggered by various factors, can lead to serious health issues. This review emphasizes the relationship among abrupt environmental changes, declining balanced microbiota composition in humans, the severity of human health problems, and a polluted surrounding environment. This review also addresses the importance and role of the human microbiome, the reasons for microbiota disturbance or reduction, and the resulting complex human health issues, especially gut, mental, psychological, and behavioral problems across all age groups, from children to adults. Possible solutions to this alarming issue include various practices: a balanced diet, an active lifestyle, an unpolluted environment, and positive social interactions, including awareness in society at the individual and community levels, from general to scientific and research fields, for maintenance of normal microorganism levels in the human body for better survival. This review also highlights a strong relationship between a healthy human microbiome and a healthy environment and raises questions about variations and uniqueness in the normal microbiome of human communities in different regions of the world. Are advanced technology and high living standards enough for a healthy and sustainable environment? Further research addressing human health, medical aspects, changes in the normal microbiota of modern humans, and environmental health may be necessary to develop more effective strategies.