The world isn't short of new 'it' diets based on so many different kinds of research. You have diet plans that eliminate carbs, diet plans that determine what you should eat according to your blood type, diets that calculate the hours and when the right time to eat is, and the list goes on.

A new study published in the journal Nature, however, suggests that you shouldn't try all of them out - because switching diets can drastically affect your intestinal health.

In the Harvard University-led study, researchers asked 10 men and women between the ages of 21 and 33 to eat either a plant-based diet rich in grains, legumes, fruits, and vegetables—or an animal-based diet consisting of meats, eggs, and cheeses. The microbiome (the population of gut bugs) in all of the participants changed drastically AND quickly.

After only five days, the veggie eaters' digestive tracts were home to bacteria types that make amino acids the building blocks of protein, from plant sugars. Meanwhile, the meat-eaters' intestines appropriately started packing more protein-digesting bacteria.

This matters because some of the bugs found in meat-eaters' digestive tracts have been linked with inflammatory bowel disease (IBD).

The results show that changing our eating strategies can affect our stomachs. So if you've noticed your belly aching, it might be worth considering how often you're changing your diet - and it might be worth mentioning to your doctor if you're in for a visit.