How Villi Help With Digestion

Intestinal villi are tiny, finger-like projections made up of cells that line the entire length of your small intestine. Villi absorb nutrients from the food you eat and then shuttle them into your bloodstream so they can travel where they're needed.

If you don't have functioning intestinal villi, you will experience malabsorption. This is when your body isn't able to absorb and make use of food. You can become malnourished or even starve, regardless of how much you eat.

This article explains the structure and function of intestinal villi. It also discusses some of the health conditions that may be related to intestinal villi damage and when you may need to consider seeing a healthcare provider.

How Big Are Your Intestinal Villi?

Your villi are really tiny—each one is no more than about 1.6 millimeters (mm) long and may be as short as 0.5 mm long. For comparison, 1.6 mm is the width of the ink line produced by the tip of a fine ballpoint pen, while 0.5 millimeters obviously is even smaller.​

Your villi alternate with depressions called crypts, where your small intestine manufactures the cells that form the villi and other parts of the intestinal lining.These crypts, when healthy, are about one-third to one-fifth as long as your villi.

While individually the villi and crypts are small, together they provide a large surface area for nutrients to be absorbed into your bloodstream. The surface becomes 6.5 times greater than it would be with a simple intestinal tube of the same size.

Conditions That Can Damage Villi

Villi can be damaged because of digestive health conditions. Intestinal villi dysfunction, or villous atrophy, also can be caused by other health conditions such as HIV infection, as well as medication.

Celiac Disease

In celiac disease, consumption of the protein gluten (found in the grains wheat, barley, and rye) triggers your immune system to attack your intestinal villi and wear them down. 

Many people with celiac disease have vitamin and mineral deficiencies when they're first diagnosed because their intestinal villi are damaged.

Inflammatory Bowel Disease

Inflammatory bowel disease, which includes Crohn's disease, also can cause your villi to erode.

Researchers think inflammatory disease may disrupt the relationship between the villi and crypts, leaving older cells in place longer in the intestinal lining.

Because these cells are more inefficient, they don't work as well in absorbing nutrients.

Lymphoma

Some studies have shown an association between certain types of lymphoma, a blood cancer, and damage to intestinal villi. They include small intestinal T-cell lymphoma, and enteropathy-associated T-cell lymphoma.

Enteropathy-associated T-cell lymphoma is closely linked to celiac disease.

Separately, a rare condition that typically affects children can cause damage to the villi. Primary intestinal lymphangiectasia (PIL), also known as Waldmann disease, is usually diagnosed before age 3 although it can be later in life.

The condition can be treated but researchers are finding an increasing amount of evidence that PIL is linked to a later diagnosis of lymphoma in both children and adults.

Medication Use

Intestinal villi damage can occur when you're taking certain medications. These include:

• Benicar (olmesartan), a blood pressure drug
• Aspirin
• Advil (ibuprofen)

In these cases, discontinuing the medication should result in your villi growing back.

Infection

Certain infections have been associated with intestinal villi damage. They include:

• Infection involving the parasite Giardia
• Infection with Helicobacter pylori (H. pylori) bacteria

Ongoing research in animal studies is finding other potential links between intestinal villi damage and infection, including toxoplasmosis. The parasitic infection is especially problematic during pregnancy or in people living with HIV.

When to See a Healthcare Provider

Intestinal villi dysfunction leads to malabsorption, so symptoms are typically consistent with nutrition deficiencies and digestive issues. These may include:

• Bouts of diarrhea
• Increased fat in your stool (steatorrhea)
• Unexplained weight loss
• Unexplained anemia
• Slow wound healing

Your healthcare provider can complete a physical exam, order blood tests, and consider other testing options to arrive at a diagnosis and discuss treatment with you.

A Word From Verywell

Intestinal villi are tiny, but when there's damage to these structures the impacts can be significant because of their key role in assuring your body receives proper nutrition. Not all conditions that affect villi are diet-related, so if you have concerns about malabsorption, contact your healthcare provider.