You may have heard that your digestive woes -- constipation or diarrhea, digestive discomfort or heartburn -- are all related to digestive enzyme insufficiencies, and that you can treat them with supplemental enzymes. The fact is that digestive enzyme deficiencies are very rare.

Lactulose is a man-made sugar, commonly used as a stool softener to treat constipation. Lactulose contains lactose and is not recommended for use by people who have been diagnosed with lactose intolerance.

We think about bacteria as harmful, disease-causing, invisible creatures. But actually, only a few species are dangerous. The majority of bacteria are good, and without them, life on Earth wouldn’t be possible.

Fats, or lipids, are an essential part of your diet. According to nutritionist Elson Haas, M.D., lipids are part of every cell membrane and every organ and tissue in your body.

A cell is the basic structure of the body. Organelle means tiny organs and these structures within a cell perform specialized functions. For example, the nucleus contains all the DNA and directs the synthesis of proteins and the process of cell replication.

The digestive process transforms food into microscopic particles that nourish the body. Humans utilize two types of digestion -- mechanical, such as chewing, and chemical, using enzymes. Digestive juices hold these enzymes and are released by the pancreas, liver and small intestine.

Bloating and fatty stool -- stools that are foul-smelling, greasy and usually rather large in volume -- are common digestive symptoms that usually indicate some type of malabsorption.

Gastroesophageal reflux disease, or GERD, affects up to 25 percent of Americans and Europeans, according to a 2009 review in "American Family Physician." Heartburn is the most prominent symptom of GERD, but other symptoms, such as chest pain or pressure, abdominal pain and cough, are not uncommon.

No matter how nutritious, your favorite foods won't do you any good in their natural, whole state. The nutrients your body gets from food must be small enough to absorb easily into your bloodstream.

The pancreas, a small organ located behind your stomach, produces digestive enzymes that flow through the pancreatic ducts to the small intestine, where they help break down food particles into usable nutrients.

Leaky gut syndrome, also known as intestinal permeability, occurs when substances, such as partially digested food particles, toxins and bacteria, leak through the intestinal wall into the bloodstream. Dietary changes are among the treatment options recommended to heal the damaged intestines.

Probiotics are bacterial species that don't cause infection in humans, but instead provide some sort of benefit to the digestive tract or other organ systems.