Plain language summary
Among patients with irritable bowel syndrome (IBS), many report wheat-consumption related symptoms. There is an on-going debate as to whether IBS symptoms from wheat consumption are due to FODMAPs (Fermentable, Oligo-, Di-, Mono-saccharides and Polyols) or wheat proteins such as gluten. The aim of this randomised double-blind controlled study was to evaluate the impact of sourdough fermentation on wheat tolerance in 26 participants with IBS as well as changes in the molecular content of bread. Participants were randomised to consume 150 grams of either sourdough-fermented or yeast-fermented bread daily for one week and adhered to a gluten-free diet one week prior to the start of intervention and throughout the intervention. Blood samples were taken and gastrointestinal symptoms were recorded at baseline and post-intervention. The protein and FODMAP content of both types of bread was recorded as well. This study found sourdough fermentation reduced both the quantities of wheat proteins and FODMAPs significantly, however was not tolerated symptomatically any better than yeast-fermented bread. This sheds light on the fact that studies using unfermented wheat products cannot necessarily be extrapolated to fermented wheat products such as sourdough bread. Based on these results, the authors conclude further large-scale clinical studies are required to better classify the role of wheat proteins in functional gastrointestinal disorders.
Abstract
Many patients suspect wheat as being a major trigger of their irritable bowel syndrome (IBS) symptoms. Our aim was to evaluate whether sourdough wheat bread baked without baking improvers and using a long dough fermentation time (>12 h), would result in lower quantities of alpha-amylase/trypsin inhibitors (ATIs) and Fermentable, Oligo-, Di-, Mono-saccharides and Polyols (FODMAPs), and would be better tolerated than yeast-fermented wheat bread for subjects with IBS who have a poor subjective tolerance to wheat. The study was conducted as a randomised double-blind controlled 7-day study (n = 26). Tetrameric ATI structures were unravelled in both breads vs. baking flour, but the overall reduction in ATIs to their monomeric form was higher in the sourdough bread group. Sourdough bread was also lower in FODMAPs. However, no significant differences in gastrointestinal symptoms and markers of low-grade inflammation were found between the study breads. There were significantly more feelings of tiredness, joint symptoms, and decreased alertness when the participants ate the sourdough bread (p ≤ 0.03), but these results should be interpreted with caution. Our novel finding was that sourdough baking reduces the quantities of both ATIs and FODMAPs found in wheat. Nonetheless, the sourdough bread was not tolerated better than the yeast-fermented bread.
Methodological quality
Jadad score
:
5
Allocation concealment
:
No
