In this study, IBS sufferers ate bread low in fermentable, oligo-, di-, mono-saccharides and polyols (FODMAP) and suffered from less IBS symptoms, which can include flatulence, abdominal pain, cramps and stomach rumbling.
IBS is disorder affecting the normal functioning of the gastrointestinal tract. On average, 11% of the adult population in the developed countries are affected by this condition.
FODMAPs are simple carbohydrates which are not absorbed in the small intestine but are fermented in the upper colon. Here, intestinal gas, abnormalities in bowel motility and visceral sensitivity develop resulting in symptoms of IBS.
The inclusion of low-FODMAP rye bread in the diet of IBS patients may also be one way that IBS patients could increase their fibre intake.
Extensive studies of FODMAPs have also implicated these carbohydrates in roles central to gluten or wheat sensitivity.
Here, researchers from the University of Helsinki used a randomised double blind controlled cross-over study, enrolling a sample size of 87 individuals.
They were given normal rye bread and low-FODMAP rye bread for one month. Individual symptoms were measured with a symptom severity scoring system (IBS-SSS) and visual analogue scale (VAS).
Quality of life was also recorded and degree of colonic fermentation was measured by a breath hydrogen test and dietary intake by food diaries.
"Our study shows that reduction of FODMAP content of a major food staple, such as rye bread, may reduce some symptoms of IBS but is not enough per se to reach adequate overall symptom control in IBS, said Dr. Reijo Laatikainen, lead author of the study and dietician at the Aava Medical Centre in Finland.
“It's likely that a holistic low-FODMAP diet is needed in most cases in order to reach adequate control of overall symptoms. Low-FODMAP rye bread seems to be one way to increase fibre intake of patients with IBS. Just like the rest of the population, IBS patients tend to have a lower than recommended intake of fibre," he added.
Whole grain rye bread is seen as a good source of fibre with content varying between 11 to 14%. In Scandinavian countries, particularly in Finland, rye can account for 28–35% of fibre intake of working age adults.
In a recent Danish study, a high intake of rye bread was linked to a lower risk of death in men. Rye bread has demonstrated good satiety qualities, and contributes to an increased intake of cereal fibre which is associated with a reduced risk of colorectal cancer.
“The key finding of the study is that the modification of FODMAP content of bread alone does have an observable effect on the symptoms of IBS,” the study concluded.
“These findings in individual symptoms are in line with the observed difference in breath hydrogen excretion, i.e. less hydrogen was excreted during the low-FODMAP rye bread period confirming the lower level fermentation of FODMAPs in colon and reduced gas accumulation.”
The accumulation of gas was of particular significance to the researchers. In using the symptom severity scoring system only pain and overall satisfaction with bowel function was measured. It did not measure individual symptoms other than bloating and abdominal pain.
“Our total score of VAS symptoms consisted of 10 different symptoms of which only one (abdominal pain) was included in the IBS-SSS,” the study noted.
“Measurements of individual symptoms and their composite end point may be more sensitive to changes than IBS-SSS, which reflects more overall satisfaction and pain during the last 10 days.”
The study noted that measurements of individual symptoms were more frequently used in low-FODMAP diet studies than IBS-SSS measurements. In addition, the accumulation of gas, measured as bread hydrogen concentration, was an objective method to assess the degree of colon fermentation.
This article was amended on 2 August 2016 that previously stated that the bread used was low-carb. The bread used was low-FODMAP.
Source: Alimentary Pharmacology & Therapeutics study
Published online ahead of print, Doi: 10.1111/apt.13726
“Randomised clinical trial: low-FODMAP rye bread vs. regular rye bread to relieve the symptoms of irritable bowel syndrome.”
Authors: Reijo Laatikainen et al.