Why women need more 'guts' than men to 'kick the cigarette butt'

Women tend to find it harder to quit smoking than men and a recent study suggests why.Scientists reported in a mouse study that the difference in gender smoking patterns and smoking's effects could be due to how nicotine impacts the brain-gut relationship.

When a person smokes tobacco, nicotine is delivered mainly to the lungs. But with skin patches and chewing tobacco, nicotine crosses the skin and into the gastrointestinal tract, respectively.

The researchers set up a 13-week experiment during which they administered nicotine-infused water">nicotine-infused water to mice. An analysis of the animals' fecal samples showed major differences in the composition of the microbiomes in male and female mice.

Levels of compounds and bacterial genes associated with the nervous system and body weight were altered in different ways in male and female mice. For example, the mice exposed to nicotine, especially the males, had lower concentrations of glycine, serine, and aspartic acid, which could weaken the addictive effect of nicotine.

In addition, nicotine-treated female mice had reduced amounts of Christensenellaceae bacteria, while the treated male mice had increased levels, which are associated with a lower body mass index.

The team said that future efforts will focus on exploring the relationship of the nicotine-gut-brain interactions on a molecular level to further understand the communication paths involved.

The study is published in ACS' journal Chemical Research in Toxicology.