Malnutrition
Because worms that live in the digestive tract of humans can cause malnutrition, they can be a symptom of a larger problem. When worms invade the small intestine, they eat the nutrients your body would normally absorb and use to grow and thrive. Unfortunately, this surplus of food is fermented by the bacteria living in the small intestine, which leads to diarrhea and causes malabsorption of nutrients such as fat-soluble vitamins A, D, E, and K.
Malnutrition can also occur when a worm infection damages the villi, tiny hair-like appendages in the lining of the small intestine that is critical for absorbing nutrients from food.
A worm infection may also prevent proper absorption of protein because many worm species secrete chemicals to break down protein into its component amino acids so it can be digested more easily by themselves. As a result, worm infections caused by species such as hookworms can lead to protein energy malnutrition (PEM) in children, who are more vulnerable to malnourishment than adults. Children with PEM often have swollen bellies and are underweight for their age. Additionally, there is evidence that intestinal worms affect how well children absorb iron from food, an important nutrient needed to form red blood cells, and can contribute to anemia.
