Reference Number: 492
Inclusions: Wheat (whole)
A variety of foods have been implicated in symptoms of patients with Irritable Bowel Syndrome (IBS) but wheat products are most frequently cited by patients as a trigger. Our aim was to investigate the effects of breads, which were fermented for different lengths of time, on the colonic microbiota using in vitro batch culture experiments. A set of in vitro anaerobic culture systems were run over a period of 24 h using faeces from 3 different IBS donors (Rome Criteria-mainly constipated) and 3 healthy donors. Changes in gut microbiota during a time course were identified by fluorescence in situ hybridisation (FISH), whilst the small-molecular weight metabolomic profile was determined by NMR analysis. Gas production was separately investigated in non-pH-controlled, 36 h batch culture experiments. Numbers of bifidobacteria were higher in healthy subjects compared to IBS donors. In addition, the healthy donors showed a significant increase in bifidobacteria (P<0.005) after 8 h of fermentation of a bread produced using a sourdough process (type C) compared to breads produced with commercial yeasted dough (type B) and no time fermentation (Chorleywood Breadmaking process) (type A). A significant decrease of ?-Proteobacteria and most Gemmatimonadetes species was observed after 24 h fermentation of type C bread in both IBS and healthy donors. In general, IBS donors showed higher rates of gas production compared to healthy donors. Rates of gas production for type A and conventional long fermentation (type B) breads were almost identical in IBS and healthy donors. Sourdough bread produced significantly lower cumulative gas after 15 h fermentation as compared to type A and B breads in IBS donors but not in the healthy controls. In conclusion, breads fermented by the traditional long fermentation and sourdough are less likely to lead to IBS symptoms compared to bread made using the Chorleywood Breadmaking Process.
Significance of this study to the baker:
The Chorleywood Breadmaking process came about in 1961 and ramped up the scale and speed of bread production. The current study shows that commercially milled wheat grain bread (extraction rate of 85%) made via the Chorleywood process is more likely to trigger Irritable Bowel Syndrome (IBS) symptoms than a 30% sourdough with a 4-hour refreshment stage or conventional yeasted bread fermented for 16 hours. In particular, the group that consumed the 30% sourdough experienced significantly less gas production than either the 16-hour fermented yeast bread or the unfermented wheat bread. In conclusion, the study suggests that those with IBS should opt for bread that has undergone a long fermentation process in favour of bread made via the Chorleywood process. More specifically, sourdough appears to be effective at reducing gas buildup.