Albenberg LG, Wu GD Diet and the intestinal microbiome: associations, functions, and implications for health and disease. Gastroenterology. 2014 May;146(6):1564-72. doi: 10.1053/j.gastro.2014.01.058. Epub 2014 Feb 4. Review.
Ferguson A, Sedgwick DM, Drummond J Morbidity of juvenile onset inflammatory bowel disease: effects on education and employment in early adult life. Gut. 1994 May;35(5):665-8.
HAAS SV, HAAS MP The treatment of celiac disease with the specific carbohydrate diet; report on 191 additional cases. Am J Gastroenterol. 1955 Apr;23(4):344-60.
Poullis A, Foster R, Shetty A, Fagerhol MK, Mendall MA Bowel inflammation as measured by fecal calprotectin: a link between lifestyle factors and colorectal cancer risk. Cancer Epidemiol Biomarkers Prev. 2004 Feb;13(2):279-84.
Stenman LK, Holma R, Eggert A, Korpela R A novel mechanism for gut barrier dysfunction by dietary fat: epithelial disruption by hydrophobic bile acids. Am J Physiol Gastrointest Liver Physiol. 2013 Feb 1;304(3):G227-34. doi: 10.1152/ajpgi.00267.2012. Epub 2012 Nov 29.
Interventional studies are often prospective and are specifically tailored to evaluate direct impacts of treatment or preventive measures on disease.
Observational studies are often retrospective and are used to assess potential causation in exposure-outcome relationships and therefore influence preventive methods.
Expanded access is a means by which manufacturers make investigational new drugs available, under certain circumstances, to treat a patient(s) with a serious disease or condition who cannot participate in a controlled clinical trial.
Clinical trials are conducted in a series of steps, called phases - each phase is designed to answer a separate research question.
Phase 1: Researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
Phase 2: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.
Phase 3: The drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
Phase 4: Studies are done after the drug or treatment has been marketed to gather information on the drug's effect in various populations and any side effects associated with long-term use.