How Vegetables Support Gut Immunity

By Michael A. Smith, MD

In case you didn’t already know it, most of your immune system is located in your gut.

That’s why if your gut isn’t healthy, neither is your immune system.

For instance, people with inflammatory bowel disease often suffer from immune hypersensitivities and other allergies as well.

Fortunately, new research shows that eating more cruciferous and leafy green vegetables is a great way to boost your gut immune system and improve your overall immune function throughout your entire body.

Let’s dive into the details!

Leafy Greens Activate the T-bet Gene

Researchers published in Nature Immunology the results of a study showing that activation of the immune gene, T-bet, is essential for the development of a subgroup of cells of the innate immune system.

Proteins from cruciferous and leafy green vegetables are known to interact with cellular receptors that activate the same pathway.1 Why is this important?

Well, it’s the T-bet gene that when activated, increases production of immune cells known as innate lymphoid cells. These immune cells play a vital role in fighting against harmful bacteria in your gastrointestinal system.

Additional research also shows that innate lymphoid cells may help lower food sensitivities, control obesity and ease inflammation associated with inflammatory bowel disease.

Dr. Gabriella Belz, one of the study investigators, said that T-bet is the gene that instructs precursor cells to develop into lymphoid cells. She believes that we can control T-bet by the food we eat. 1, 2

Leafy greens and cruciferous vegetables activate the gene. It’s believed that these vegetables contain proteins that interact with cell-surface receptors that switch on T-bet activity. On the other hand, refined sugars and saturated fats could suppress the gene.

Either way, food influences our genes! So, will you use food to influence genes in a positive or negative way? That’s the ultimate question.

T-bet Ultimately Increases Interleukin-22

So here’s how it works:

  1. You eat organic cruciferous vegetables, like kale, or leafy greens like spinach.
  2. Proteins from the vegetables interact with cell-surface proteins.
  3. These proteins send a signal to the cell’s nucleus that result in T-bet expression.
  4. T-bet influences precursor cells to develop into innate lymphoid cells.
  5. The lymphoid cells travel to the gut and release interleukin-22.
The effects of interleukin-22 in the gut are as follows:

  • Improved mucosal cell function3
  • Improves immune cell numbers, like T-cell and Natural Killer cells4
  • Improves antimicrobial defenses4
  • Helps restore a normal healthy flora (microorganisms)4
So, the bottom line is that cruciferous and leafy green vegetables improve your gut immunity and may lower the risk of food sensitivities, infections, and inflammatory bowel conditions. Today, we understand more clearly the detail of how it all happens.

By the way, a diet high in refined sugars might destroy — through a toxic reaction called glycation — the cell-surface receptors needed to express T-bet. And this is pretty amazing. Food can directly or indirectly influence how your genes are expressed.

The Bottom Line – Eat More Cruciferous & Leafy Green Veggies

It’s really not that hard to work more veggies into your diet. For instance, add kale and parsley to your breakfast fruit smoothie. It will change the color a dark green but not affect the taste. Or try an egg-white omelet and double the amount of spinach and purple onions.

For lunch, try a veggie burger and top it with leafy greens and extra spinach. Couple that with a small cup of vegetable soup and you’re good to go … until dinner.

Try this for dinner: Eggplant, goat cheese, kale and spinach sandwich. Throw in some grilled broccoli and cauliflower, and you’ll satisfy your hunger and help your gut immune system with all of the cruciferous and leafy green veggies.

That doesn’t sound so hard, does it?


  1. Nature Immunology. (2013) doi:10.1038/ni.2545 (
  2. March 14, 2013.
  3. Immunology. 2011 Apr;132(4):453-65. doi: 10.1111/j.1365-2567.2011.03410.x.
  4. Semin Immunopathol. (2010) 32:17–31. DOI 10.1007/s00281-009-0188-x


crispr cas9 gene editing said...

From a personal point of view, the vegetables are easy to digest after eating, so that we always maintain the intestinal patency, and therefore will be very happy to work. From a scientific point of view. Chlorophyll of vegetables can promote the activation of the digestive gene, thus accelerating the bowel movement.

Life Extension said...

crispr cas9 gene editing- Thanks for chiming in! Leafy greens do contain chlorophylls that neutralize chemicals & pesticides!

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