Is the human mouth cleaner than the human butt?

The human mouth and butt are both host to a diverse array of bacteria, with the mouth containing around 700 different species and the gut harboring over 1,000 species. However, the oral cavity is constantly exposed to the external environment through food and air intake, potentially introducing harmful pathogens. On the other hand, the gastrointestinal tract is protected by stomach acid and a mucus layer, which helps to prevent the colonization of harmful bacteria. Therefore, while neither the mouth nor the butt can be considered "cleaner" than the other in an absolute sense, the gut may have more robust mechanisms for maintaining a healthy bacterial balance.