Kathleen Ignatoski, Ph.D., Research Laboratory Specialist, Department of Pharmacology (Jenkins Laboratory), University of Michigan Medical School
Epithelial cells of the gut do more than just absorb and process food. They provide a barrier between the body and the outside environment. An important part of that barrier is a protein called Ankyrin-G, here stained in green, which helps keep the cells tightly attached to one another, preventing invasion. Trillions of bacteria inhabit the gut. Many of these are so-called commensals, which play an important role in digestion and even in metabolism of their host. You can live in harmony with them, as long as the gut wall is intact. You may even add to their numbers by consuming probiotics. However, some rather nasty pathogens live in the gut too. One of these is Clostridium difficile (commonly known as C. diff) which can cause inflammation of the colon, called colitis, resulting in severe watery diarrhea, dehydration and even death. The elderly, people with weakened immune systems are particularly susceptible.