As scientists continue to explore the link between gut bacteria and mental health, Canadian researchers have discovered that stress in the early stages of life can alter the bacterial population in the gut—which may have lasting implications when it comes to a healthy brain and mood in adulthood.
In a study published online in the journal Nature Communications, experts from the Family Digestive Health Research Institute at McMaster University in Ontario revealed that stress in infancy may trigger changes in the developing microbiome, which in turn may increase the risk of developing anxiety and depression later in life.
For the purpose of the study, researchers used two groups of newborn mice: one with normal gut bacteria and one with no gut bacteria. To analyze the effects of early life stress, the mice in both groups were separated from their mothers for a few hours each day for nearly three weeks.
Interestingly, while both groups of mice exhibited elevated stress hormone levels, those with normal gut bacteria displayed anxious or depressed behavior as well as impaired digestive function—symptoms not seen in the mice with no gut bacteria. Lead author Dr. Premysl Bercik and his colleagues believe even small changes in gut bacteria during a child’s early years may have “profound effects” on mood and behavior as an adult.