Both diet and gender-and the interactions between the two-influence the make-up of communities of gut microbiota, reports to a study published this week in Nature Communications.

Intestinal microbial communities are particularly abundant and diverse, and promote host development, nutrition, and immunity. Diet is known to alter microbiota composition, implying that dietary treatments might alleviate diseases arising from altered microbial composition. However, it remains unclear whether diet effects are general or depend on host genotype.

Daniel Bolnick and colleagues investigated the roles of gender and diet on the make-up of vertebrate gut microbiota using data from wild fish (stickleback and Eurasian perch), captive sticklebacks, laboratory mice, and humans. In each case, diet affected microbiota composition differently in males and females. The underlying mechanism remains to be determined, but the authors propose it may be linked to gender differences in hormone or immune function. They also note that future studies of gut microbiota should account for gender, as should any attempts at therapeutic manipulation of microbiota to treat gastrointestinal conditions.