When it comes to human behaviors that contribute to decreased exposure to microbes, there are many. It starts within the womb as the maternal microbiome exposes the fetus to various microorganisms. The health and variety of the bacteria a part of the mother can either be robust and contribute to a strong immune system for the baby, or be lacking and weak. Additionally, decreased exposure to microbes occurs through various forms of sanitation including hospital sterilization, handwashing, and personal hygiene. The treatment of our food and water systems also plays a role in decreased microbe exposure as companies use pesticides, herbicides, and fertilizer on their crops to kill microorganisms that are often beneficial to the soil systems and our health. As far as our water systems, treatment facilities often use chlorine and other chemicals to filter out harmful as well as beneficial bacteria. Another critical, and likely the most dramatic behavior leading to a decreased exposure to microbes would be the use of antibiotics. Since they are used to kill the harmful bacteria, but consequently also kill the good bacteria, they destroy a large amount of the bacteria residing in the gut microbiome.