Safety of sourdough fermented wheat products for coeliacs

Researchers in Italy have recently published the results of two studies into the safety for coeliacs of wheat products rendered gluten-free using sough dough fermentation. One of the studies was aimed at showing the safety of sweet baked sourdough products for young patients with coeliac disease while the other evaluated the safety of daily administration of baked sourdough products amongst adults with coeliac disease.

The first study utilised lactobacilli and fungal proteases to degrade the gluten component of wheat flour to <10 ppm. The flour was then spray dried and used to make sweet baked goods. Eight young patients with coeliac disease in remission were enrolled for a pilot-scale clinical challenge, whereby they consumed 200 g of sweet baked goods, equivalent to 10 g of native gluten, each day for 60 days.

Two patients discontinued the challenge due to daily compliance difficulties. Tests carried out on the remaining patients at the completion of the trial returned normal results. While the researchers concluded that the fermented wheat flour products were not toxic for this group of patients they are not able to recommend these products for coeliacs until a formal trial has been done.

In the second study, adults with coeliac disease were randomly assigned to consumption of 200 g per day of natural flour baked goods (80,127 ppm gluten), extensively hydrolysed flour baked goods (2,480 ppm residual gluten), or fully hydrolysed flour baked goods (8 ppm residual gluten) for 60 days.

All six patients in the group who consumed natural flour baked goods had increased levels of anti-tissue transglutaminase antibodies and small bowel deterioration. The two patients who ate baked goods that had been extensively hydrolysed had no clinical complaints but tests showed they had developed subtotal atrophy. The five patients who ate the fully hydrolysed flour baked goods had no clinical complaints and all tests returned normal results.

Based on these findings, the authors concluded a 60-day diet of baked goods made from fully hydrolysed wheat flour, manufactured with sourdough lactobacilli and fungal proteases, was not toxic to patients with coeliac disease.

Reference 1: Di Cagno et al. 2010. Journal of Pediatric Gastroenterology and Nutrition. DOI: 10.1097/MPG.0b013e3181f22ba4.

Reference 2: Greco et al. 2010. Clinical Gastroenterology and Hepatology. DOI: 10.1016/j.cgh.2010.09.025.