We constantly evaluate the chemicals emitted by others, influencing our social interactions and relationships.

Chemical signaling between individuals can impact biological responses, such as menstrual cycle synchronization among women.

Humans may have vestigial pheromonal effects, as evidenced by chemical signaling that can influence social and reproductive behaviors.

When selecting a mate, humans are drawn to those with immune system compositions that are most different from their own, which is often perceived through their smell.

Pheromones are chemicals that humans release, which can modulate our biology and emotions, although the existence of true human pheromonal effects is still controversial.

Pheromonal effects in animals, such as the Coolidge effect, show that chemical signals can influence mating behavior.

The early assembly of an infant's microbiota is dynamic and can be influenced by various factors, including whether they are breastfed or formula-fed, exposure to pets, and antibiotic use, which can all shape their microbial identity.

Exposure to microbes from the environment is essential for educating our immune system and maintaining its balance.

Microbiota are not only present in the gut but also in the mouth, nose, and skin, and they play a crucial role in our overall health by forming a dense and complex ecosystem that interacts with our body.