Sourdough-leavened bread improves postprandial glucose and insulin plasma levels in subjects with impaired glucose tolerance
- 464 Downloads
Sourdough bread has been reported to improve glucose metabolism in healthy subjects. In this study postprandial glycaemic and insulinaemic responses were evaluated in subjects with impaired glucose tolerance (IGT) who had a meal containing sourdough bread leavened with lactobacilli, in comparison to a reference meal containing bread leavened with baker yeast. Sixteen IGT subjects (age range 52–75, average BMI 29.9 ± 4.2 kg/m²) were randomly given a meal containing sourdough bread (A) and a meal containing the reference bread (B) in two separate occasions at the beginning of the study and after 7 days. Sourdough bread was leavened for 8 h using a starter containing autochthonous Saccharomyces cerevisiae and several bacilli able to produce a significant amount of d-and l-lactic acid, whereas the reference bread was leavened for 2 h with commercial baker yeast containing Saccharomyces cerevisiae. Plasma glucose and insulin levels were measured at time 0, 30, 60, 120, and 180 min. In IGT subjects sourdough bread induced a significantly lower plasma glucose response at 30 minutes (p = 0.048) and a smaller incremental area under curve (AUC) Δ 0–30 and Δ 0–60 min (p = 0.020 and 0.018 respectively) in comparison to the bread leavened with baker yeast. Plasma insulin response to this type of bread showed lower values at 30 min (p = 0.045) and a smaller AUC Δ 0–30 min (p = 0.018). This study shows that in subjects with IGT glycaemic and insulinaemic responses after the consumption of sourdough bread are lower than after the bread leavened with baker yeast. This effect is likely due to the lactic acid produced during dough leavening as well as the reduced availability of simple carbohydrates. Thus, sourdough bread may potentially be of benefit in subjects with impaired glucose metabolism.
KeywordsSourdough bread Impaired glucose tolerance Lactic acid
We would like to thank Ms. Alba Canu from “Centro di Restauro Soprintendenza Beni Archeologici Province di Sassari e Nuoro” for her assistance in ESEM analysis, and Gloria Calì from the Westminster School of Sassari for her assistance in checking the manuscript.
- 10.Corsetti A, Lavermicocca P, Morea M, Baruzzi F, Tosti N, Gobbetti M (2001) Phenotypic and molecular identification and clustering of lactic acid bacteria and yeasts from wheat (species Triticum durum and Triticum aestivum) sourdoughs of Southern Italy. Int J Food Microbiol 64:95–104PubMedCrossRefGoogle Scholar
- 11.Damiani P, Gobbetti M, Cossignani L, Corsetti A, Simonetti MS, Rossi J (1996) The Sourdough microflora. Characterization of hetero- and homo-fermentative lactic acid bacteria, yeast and their interactions on the basis of the volatile compounds produced. Lebensm Wiss u Technol. 29:63–70CrossRefGoogle Scholar
- 12.Foschino R, Terraneo R, Mora D, Galli A (1999) Microbial characterization of sourdoughs for sweet baked products. Ital J Food Sci 1:19–28Google Scholar
- 13.Gobbetti M, Corsetti A, Rossi J, La Rosa F, Dé Vincenzi S (1994) Identification and clustering of lactic acid bacteria and yeast from wheat sourdoughs of central Italy. Ital J Food Sci 1:85–94Google Scholar