How can bacteria impact the human body?

Bacteria have a complex relationship with the human body, and their impact can vary significantly. While some bacteria are pathogenic and can cause diseases, many bacteria are actually beneficial and play essential roles in maintaining human health. For instance, the human gut microbiome, which is a community of trillions of bacteria, helps with digestion, supports the immune system, and even contributes to mental health through the gut-brain axis.

The presence of beneficial bacteria helps to outcompete harmful bacteria, thus contributing to the body’s ability to prevent infections and maintain overall balance. This dual nature of bacteria—being capable of both causing harm in the case of pathogenic strains and providing beneficial effects in the case of non-pathogenic strains—supports the idea that bacteria can be helpful or harmful. Therefore, the correct understanding of bacteria's impact is that they are not strictly detrimental but can have both positive and negative effects on human health.