London, March 5 : An immune cell population essential for intestinal health could be controlled by adding leafy greens in your diet, a new study has suggested.

The immune cells, named innate lymphoid cells (ILCs), are found in the lining of the digestive system and protect the body from `bad' bacteria in the intestine.

They are also believed to play an important role in controlling food allergies, inflammatory diseases and obesity, and may even prevent the development of bowel cancers.

Dr Gabrielle Belz, Lucie Rankin, Dr Joanna Groom and colleagues from the Walter and Eliza Hall Institute's Molecular Immunology division have discovered the gene T-bet is essential for producing a population of these critical immune cells and that the gene responds to signals in the food we eat.

Dr Belz said the research team revealed T-bet was essential for generating a subset of ILCs which is a newly discovered cell type that protects the body against infections entering through the digestive system.

"In this study, we discovered that T-bet is the key gene that instructs precursor cells to develop into ILCs, which it does in response to signals in the food we eat and to bacteria in the gut," Dr Belz said.

"ILCs are essential for immune surveillance of the digestive system and this is the first time that we have identified a gene responsible for the production of ILCs," she stated.

Dr Belz said that the proteins in green leafy (cruciferous) vegetables are known to interact with a cell surface receptor that switches on T-bet, and might play a role in producing these critical immune cells.

"Proteins in these leafy greens could be part of the same signalling pathway that is used by T-bet to produce ILCs," Dr Belz said.

ILCs are essential for maintaining the delicate balance between tolerance, immunity and inflammation. Rankin said the discovery had given the research team further insight into external factors responsible for ILC activation.

ILCs produce a hormone called interleukin-22 (IL-22), which can protect the body from invading bacteria, Dr Belz said.

"Our research shows that, without the gene T-bet, the body is more susceptible to bacterial infections that enter through the digestive system. This suggests that boosting ILCs in the gut may aid in the treatment of these bacterial infections," she said.

ILCs help to maintain a `healthy' environment in the intestine by promoting good bacteria and healing small wounds and abrasions that are common in the tissues of the gut. They may also have a role in resolving cancerous lesions.

"Understanding the biology of ILCs and the genes that are essential for generating them will help us to develop methods of targeting these cells," Dr Belz said.

"This might include boosting ILCs in situations where they may not be active enough, such as infections or some cancers, or depleting them in situations where they are overactive, such as chronic inflammatory disease," she said.

The research has been published in the journal Nature Immunology. (ANI)