Numerous microorganisms that are important to the health of their host are found in abundance in the human gut. They can, however, also be potentially dangerous because of the alteration in their composition that occurs when the gut ecosystem experiences aberrant changes as a result of the use of antibiotics, sickness, stress, age, poor dietary practices, and lifestyle choices. Dysbiosis of the gut micro biota on humans has harmful health effects that can result in a number of chronic disorders. The potential of probiotics to treat certain disorders has led to much research into them. They are typically thought of as helpful microbes; additionally, when their products are supplied to humans in sufficient doses, they act as health adjuvants. Probiotics can prevent the beginning of disease through a number of processes, including altering gut bacteria, producing short-chain fatty acids, reducing intestinal pH, producing antimicrobial compounds, and suppressing epithelial binding growth. Additionally, they help to inhibit the invasion of pathogenic organisms, regulate the transfer of food antigens, enhance intestinal barrier performance, and alter host immunological responses. Probiotic tests have revealed encouraging outcomes in the prevention of diseases such as diarrhea, irritable bowel syndrome, colon cancer, and Crohn’s disease. Numerous epidemiological and experimental investigations, particularly those focusing on the gut microbiota, have contributed to shed light on the role of probiotics as preventative agents. This review provides a potential target for the illness prevention and treatment by summarizing and discussing the roles and potential mechanisms of gut bacteria in human health and disorders.