A new study suggests that your junk food cravings may be related to your gut bacteria.
Researchers from the University of New Mexico and the University of California, San Francisco, found that bacteria can influence mood and activate hunger-causing hormones. The study, published in the journal BioEssays, found that differences in microbial genes could explain why different people have different food cravings.
"Microbial genes outnumber human genes by 100 to 1 in the intestinal microbiome," the research states, and humans have as many as 36,000 bacteria in their gastrointestinal tracts. When microbes are that prevalent, "different species compete for space and nutrients in our intestines, and the more dominant ones may have more influence on their humans," according to The Atlantic.
Therefore, people with specific cravings for fat or sugar may have more of certain microbes than others. "Individuals who are 'chocolate desiring' have different microbial metabolites in their urine than 'chocolate indifferent' individuals, despite eating identical diets," the study states. Certain metabolites are also linked to changes in mood, which could explain why different infants cry different amounts.
You're not destined to be ruled by your gut bacteria, though — what you eat can influence the microbes, so resisting that sugar craving could be even more helpful in the long run.