The immune system exercises constant vigilance to protect the body from external threats–including what we eat and drink. A careful balancing act plays out as digested food travels through the intestine. Immune cells must remain alert to protect against harmful pathogens like Salmonella, but their activity also needs to be tempered since an overreaction can lead to too much inflammation and permanent tissue damage.
When you think parasites you probably don’t think of anything helpful. However, this isn’t the case and certain parasites inadvertently help the host by helping themselves. In fact, researchers have discovered how intestinal worm infections cross-talk with gut bacteria to help the immune system.
Researchers at the UNC School of Medicine found that people with anorexia nervosa have very different microbial communities residing inside their guts compared to healthy individuals and that this bacterial imbalance is associated with some of the psychological symptoms related to the eating disorder.
Bacteria aren’t the only nonhuman invaders to colonize the gut shortly after a baby’s birth. Viruses also set up house there, according to new research at Washington University School of Medicine in St. Louis. All together, these invisible residents are thought to play important roles in human health.