Researchers have found that eliminating foods known to stimulate intestinal inflammation — a dietary approach known as the autoimmune protocol diet — improves clinical outcomes in inflammatory bowel disease (IBD) patients.
The small study, “Efficacy of the Autoimmune Protocol Diet for Inflammatory Bowel Disease,” was published in the journal Inflammatory Bowel Diseases.
IBD is a complex disease where the interplay of both genetic and environmental factors influences disease onset and progression. But while researchers have identified approximately 200 genes as risk factors for IBD, their contribution to the disease is limited, accounting for up to 13 percent of Crohn’s disease (CD) and 7 percent of ulcerative colitis (UC) cases.
Among environmental factors, diet and the gut microbiome — the collection of natural microbes that populate the intestine — are considered the two major factors to influence disease course.
Accumulating evidence suggests that modifications to diet can improve IBD clinical outcomes, but further work is required to identify dietary factors that may be useful in a nutrition-based therapy.
The so-called autoimmune protocol (AIP) diet stems from the Paleolithic diet — characterized by consumption of meats, fish, fruits, vegetables, nuts and seeds, and the avoidance of dairy products, legumes and grains.
As such, “the AIP [autoimmune protocol] diet focuses on an initial elimination phase of food groups including grains, legumes, nightshades, dairy, eggs, coffee, alcohol, nuts and seeds, refined/processed sugars, oils, and food additives,” the authors wrote.
This diet’s main objective is to avoid consuming food (and medications) that may trigger gut inflammation and changes in its microbiome.
Researchers conducted a prospective study to evaluate the potential efficacy of the autoimmune protocol diet in patients with active CD and UC.
Fifteen patients — nine with CD and six with UC — were put an autoimmune protocol diet that ran from Sept. 5 to Nov. 18, 2016. It included a six-week staged elimination of avoided foots, followed by a five-week strict-adherence or maintenance phase. Patients had IBD for a mean period of 19 years and almost half of them reported using biologicals for up to two years before the study.
The elimination phase gradually removed from patients’ diet “grains, legumes, night-shades, dairy, eggs, coffee, alcohol, nuts and seeds, refined/processed sugars, oils, and food additives,” which remained absent throughout the study.
Results showed that after six weeks, 11 of the 15 patients achieved clinical remission — six with CD and five with UC — and maintained remission during the maintenance phase.
Researchers also “identified improvements in FC [fecal calprotectin, a biomarker of intestinal inflammation] along with endoscopic improvements in the mucosal appearance in most patients undergoing follow-up endoscopy,” they wrote.
These results suggest that dietary modification is a potential treatment to use in combination with conventional IBD therapy (50 percent of study participants used biological) in patients with moderate-to-severe disease.
“Our study demonstrates that dietary modification focused on elimination of potentially immunogenic or intolerant food groups has the potential to improve symptoms and endoscopic inflammation in patients with IBD,” the researchers concluded.
These preliminary findings require validation in large randomized studies.