When poet Walt Whitman wrote that we “contain multitudes,” he was speaking metaphorically, but he was correct in the literal sense. Every human being carries over 100 trillion individual bacterial cells within the intestine – ten times more cells than comprise the body itself.
Now, David Artis, PhD, associate professor of Microbiology, along with postdoctoral fellow David Hill, PhD, from the Perelman School of Medicine at the University of Pennsylvania, and collaborators from The Children’s Hospital of Philadelphia and institutions in Japan and Germany, have found that these commensal bacteria might play an important role in influencing and controlling allergic inflammation. The commensal relationship that develops between humans and internal bacteria is one in which both humans and bacteria derive benefits.
The study – appearing this week in Nature Medicine – suggests that therapeutic targeting of immune cell responses to resident gut bacteria may be beneficial in treating allergic diseases.
The researchers build on previous work demonstrating that selective manipulation of the commensal bacterial population could affect the immune system. “Studies in human patients suggest that changes in commensal populations or exposure to broad spectrum antibiotics can predispose patients to the development of systemic allergic diseases,” Hill explains.

A thorough medical history, physical examination, and routine blood tests help rule out other conditions that could be causing the symptoms. This information often provides helpful clues, such as a family history of arthritis or unexplained liver disease.
Blood tests can determine whether the amount of iron stored in the body is too high. The transferrin saturation test reveals how much iron is bound to the protein that carries iron in the blood. Transferrin saturation values higher than 45 percent are considered too high.
The total iron binding capacity test measures how well your blood can transport iron, and the serum ferritin test shows the level of iron in the liver. If either of these tests shows higher than normal levels of iron in the body, doctors can order a special blood test to detect the HFE mutation, which will confirm the diagnosis. If the mutation is not present, hereditary hemochromatosis is not the reason for the iron buildup and the doctor will look for other causes.
A liver biopsy may be needed, in which case a tiny piece of liver tissue is removed and examined with a microscope. The biopsy will show how much iron has accumulated in the liver and whether the liver is damaged.
Hemochromatosis is considered rare and doctors may not think to test for it. Thus, the disease is often not diagnosed or treated. The initial symptoms can be diverse, vague, and mimic the symptoms of many other diseases. The doctors also may focus on the conditions caused by hemochromatosis—arthritis, liver disease, heart disease, or diabetes—rather than on the underlying iron overload. However, if the iron overload caused by hemochromatosis is diagnosed and treated before organ damage has occurred, a person can live a normal, healthy life.
Hemochromatosis is usually treated by a specialist in liver disorders called a hepatologist, a specialist in digestive disorders called a gastroenterologist, or a specialist in blood disorders called a hematologist. Because of the other problems associated with hemochromatosis, other specialists may be involved in treatment, such as an endocrinologist, cardiologist, or rheumatologist. Internists or family practitioners can also treat the disease.