Table 4.
Summary of interventions studies investigating the impact of sourdough bread in gastrointestinal health and disease.
| Study | Study Design | Study Population | Intervention | Control | Duration | Other Findings |
|---|---|---|---|---|---|---|
| Korem et al., 2017 [170] | Randomised crossover trial | Healthy, n = 20 |
145 g sourdough wholegrain wheat bread | 110 g white wheat bread | 1 week | Significant interpersonal variability in glycaemic responses Baseline microbiome could predict type of bread that results in lower glycaemic response in each participant |
| Polese et al., 2018 [171] | Double-blind, cross-over RCT | Healthy, n = 17 |
2 sourdough croissants | 2 brewer’s yeast croissants | Single study day | 11% decrease in gastric volume AUC 3 h post-consumption (p = 0.02) 30% lower hydrogen production during the 4 h post-consumption (p = 0.03) Milder abdominal discomfort (p = 0.002), bloating (p = 0.001) and nausea (p = 0.004) |
| Raninen et al., 2017 [172] | Randomised cross-over trial | Minor gastrointestinal symptoms, n = 8 |
6–10 slices/day of sourdough wholegrain rye bread | 6–10 slices/day of wheat bread enriched with bioprocessed (fermented) rye bran | 4 weeks | Significant difference in exhaled breath volatile organic compound profile between groups in fasting state (p = 0.026). No difference was shown at 30, 60 and 120 min after a standardised meal |
| Laatikainen et al., 2016 [11] | Randomised, double-blinded, cross-over trial | Irritable bowel syndrome, n = 87 |
7–8 slices/day low FODMAP sourdough rye bread | 7–8 slices/day traditional sourdough rye bread | 4 weeks | Lower breath H2 in low FODMAP rye bread group compared to traditional rye bread (median AUC 53 ppm vs 73; p = 0.01) Milder flatulence (p = 0.04), abdominal cramps (p = 0.01), rumbling (p = 0.001) and total symptoms (p = 0.02) No difference in IBS-SSS (p = 0.40). Lower weight in low FODMAP rye bread compared to traditional rye bread (mean difference −0.5 kg, 95% CI –0.9 –0.0; p = 0.03) |
| Laatikainen et al., 2017 [164] | Double-blinded RCT | Irritable bowel syndrome with subjective wheat intolerance, n = 26 |
6 slices/day sourdough wheat bread (fermentation time > 12 h) | 6 slices/day yeast-fermented wheat bread (fermentation time approx. 2 h) | 7 days | No difference in gastrointestinal symptoms or markers of low-grade inflammation. Worse symptoms of tiredness (p = 0.01), joint symptoms (p = 0.03) and “decreased alertness” (p = 0.003) |
| Di Cagno et al., 2010 [173] | Non-randomised, uncontrolled study | Coeliac disease, n = 8 |
200 g/day baked products with sourdough wheat flour (10 g hydrolysed gluten) | None | 60 days | All patients had normal IgG and IgA-AGA and IgA-tTG antibodies values at the end of the intervention period |
| Mandile et al., 2017 [174] | RCT | Coeliac disease, n = 20 |
Sourdough wheat bread (fermented with lactobacilli and yeast) | Traditional wheat bread | 3 days | No increase in INF-γ secretion Mobilisation of INF-γ secreting cells in the blood following traditional wheat bread |
IBS-SSS Irritable Bowel Syndrome Severity Scoring System; RCT, randomized controlled trial.