Now, researchers have found that intestinal immunity cells are actually recruited by other parts of the body and venture beyond the gut to help repair muscle injuries and damaged liver tissue.

What's more, these new findings came about by chance when, during routine cataloguing, researchers at Harvard Medical School (HMS) found a specific class of T cells – Tregs – among muscle cells. Tregs are normally found in the colon to help maintain gut health and are rarely seen outside the small and large intestines.

"I stumbled upon some cells that looked very similar and had all the same features of Tregs that derive from the gut," said Bola Hanna, co-author of the study and research fellow in immunology at HMS. "This caught our attention because we know these cells are produced in the gut and are shaped by the microbiota."