Patient - Irritable Bowel Syndrome (IBS) Diet and Nutrition

Agazzi A, De Ponti F, De Giorgio R, et al. "Review of the implications of dietary tryptophan intake in patients with irritable bowel syndrome and psychiatric disorders." Digestive and Liver Disease." 35:590-595, 2003.
In this review, the possible role of the essential amino acid L-tryptophan or 5-hydroxytryptophan in the production of serotonin (a neurotransmitter) is addressed as well as its role in affecting certain central and peripheral nervous system disorders, including depression and irritable bowel syndrome. L-Tryptophan may represent a link between apparently different functional disorders. On the basis of estimates showing that approximately 20% of patients with functional bowel disorders seeking care also have psychological symptoms, an attempt is made to provide a conceptual framework for defining the possible role of L-tryptophan in this population.

Alper BS.  "Evidence-based medicine. Antibody-guided food elimination may reduce symptoms of IBS."  Clinical Advisor. 8(2): 122, 2005.
This article comments on a 12-week study with 150 patients with IBS who were tested for immunoglobulin (Ig)G antibodies against 29 different foods. One group was advised to follow a diet that eliminated all foods for which they tested positive (most commonly yeast, milk, whole eggs, wheat, cashew nuts and peas). The control group was advised to eat a diet that eliminated the same number of foods, but foods for which they did not have IgG antibodies (sham diet). The antibody-based elimination diet reduced IBS symptoms 38.5 points overall on a 500-point scale and by 98 more points in those who fully followed the diet. Using the outcome of improved global rating, responses were 28% in the elimination diet vs. 17% in those who were on the sham diet; and 54% vs. 15% in those who fully followed the diet. When eliminated foods were reintroduced into the diet, they led to greater worsening of symptoms in the true-diet group compared with the sham-diet group.

Dear KL, Elia M,  Hunter JO. "Do interventions which reduce colonic bacterial fermentation improve symptoms of irritable bowel syndrome?" Digestive Diseases & Sciences. 50(4):758-66, 2005.
This study assessed the relationship between IBS symptoms and fermentation rates in the colon. Subjects used either a standard diet, a standard diet with the antibiotic metronidazole, or a fiber-free diet to reduce fermentation. Both metronidazole and a no-fiber diet significantly reduce total gas and improved abdominal symptoms. The study indicated that IBS may be associated with rapid excretion of gaseous products of fermentation and when this is reduced IBS symptoms may improve.

Floch MH. "Use of diet and probiotic therapy in the irritable bowel syndrome: analysis of the literature." Journal of Clinical Gastroenterology. 39(5 Suppl):S243-6, 2005.
This report reviews the use of diet and probiotics in patients with irritable bowel syndrome (IBS) in published reports. Dietary factors can be important in inducing symptoms that occur in patients with the IBS. Dietary intolerances, dietary allergies, specific food metabolites, and regular diet contents all may act as triggers and aggravate the symptoms of IBS. If proven to cause IBS symptoms, their elimination can result in the resolution of that patient's IBS. The most common dietary factor evaluated in this review was bran, and the most common probiotic used was Lactobacillus plantarum. Although investigations have shown that bran may be helpful in some patients, a complete review of the literature does not reveal conclusive evidence that diet therapy is effective in IBS. From the limited reports on probiotics, there appears to be a trend to decreasing symptoms. Much more research is needed to study both dietary factors and probiotics in these areas.

Floch MH, Narayan R. "Diet in the irritable bowel syndrome. Journal of Clinical Gastroenterology. 35(1 Suppl): S45-52, 2002.
Present national dietary guidelines for people with IBS recommend dietary treatment with fiber for IBS patients with constipation. Diet recommendations are made based on symptoms and may differ by predominant symptom such as constipation, diarrhea, and pain or bloating. This article reviews the relationship of foods to IBS, discusses food intolerances and hypersensitivities, and provides recommendations for diet therapy. The role of dietary fiber, both soluble and insoluble, is reviewed as are the use of probiotics and prebiotics for IBS. Few studies substantiate exact diets, but broad dietary strategies can be recommended for different IBS symptoms.

Lea R. Whorwell PJ. "The role of food intolerance in irritable bowel syndrome." Gastroenterology Clinics of North America. 34(2):247-55, 2005.
Irritable bowel syndrome patients frequently believe that food intolerances are to blame for many of their symptoms, although not uncommonly this is caused by the nonspecific increase in gut motility that occurs with food ingestion. Nevertheless, dietary manipulation may result in substantial improvement in IBS symptoms if it is individualized to the particular patient. By further understanding the mechanisms involved in dietary intolerance, it should be possible to optimize the benefits of this approach to treatment.

Santelmann H, Howard JM. "Yeast metabolic products, yeast antigens and yeasts as possible triggers for irritable bowel syndrome." European Journal of Gastroenterology & Hepatology. 17(1):21-6, 2005 Jan.
This review looks at the possible involvement of Candida and yeasts in the development of IBS. While its role in the development of IBS is unclear, there is increasing evidence for yeasts being able to cause IBS-symptoms in sensitized patients. More research is needed, however, before antifungal treatment can be recommended as first line treatment for IBS.

Zar S, Mincher L, Benson MJ, et al. "Food-specific IgG4 antibody-guided exlucsion diet improves symptoms and rectal compliance in irritable bowel syndrome." Scandinavian Journal of Gastroenterology. 40(7):800-7, 2005.
Dietary modification may improve IBS symptoms. IgG4 antibodies to common food antigens are elevated in IBS with IgG4 antibodies to milk, eggs, wheat, beef, pork and lamb being the most common. This study evaluated the effect of an exclusion diet based on IgG4 titres on IBS symptoms. Twenty-five IBS patients who went on an exclusion diet showed significant improvement in IBS symptoms, including pain severity and frequency, bloating severity, satisfaction with bowel habits and effect of IBS on life in general at 3 months. Symptom improvement was maintained at six months.