Bacteria and Circadian Rhythms

Researchers from the Argonne National Library and the University of Chicago recently conducted a study concerning microbes that reside in mammalian stomachs and intestines that appear to have an affect on circadian rhythms.  Previous research has verified the relationship between metabolism and circadian rhythms, so it is not outrageous to assume that the microorganisms that aid in our digestion can also have an affect on how our bodies handle day and night cycles.  There is evidence that these bacteria also have an affect on allergies, mental health, and weight.

Using mice to conduct the experiment, researchers found that mice with the natural set of microbes (the control) exhibited normal daily microbial cycles, which were defined as having different species flourishing during different parts of the day and producing different compounds.  The compounds, in turn, facilitate the expression of circadian clock genes in the liver.  Another set of mice were given a high fat diet, which reduced the variation in microbial cycle, so less compounds were produced and the mice quickly gained weight.  This, researchers hypothesize, is because too much fat changes the natural compounds microbes produce.  A new set of mice, the “germ fee” mice, displayed a disrupted circadian cycle as well, however without the weight gain.  This demonstrates the possibility of a strong bond between bacteria and the regulation of circadian rhythms.  Understanding the microscopic organisms that reside in us can give us valuable insight into our dietary needs and circadian rhythms.  The researchers hope to continue their exploration of what other diets trigger these responses.