Mouse feeding study and microbiome analysis of sourdough bread for evaluation of its health effects

Abstract

Sourdough bread fermented with yeast and lactic acid bacteria (LAB) is thought to have various beneficial health effects. However, its beneficial effects were not fully evaluated with in vivo mouse model. To evaluate these effects in vivo, a mouse feeding study and microbiome analysis of white bread containing 40% sourdough (WBS) and yeast-leavened white bread (WB) were performed. Although feed consumption and body weight increased with WBS, the glycemic index was reduced, suggesting a diabetes-lowering effect, probably due to the presence of dietary fiber and short-chain fatty acids (SCFA). In addition, a mineral absorption test showed that WBS increased magnesium absorption owing to phytate degradation during fermentation. Interestingly, WBS decreased total cholesterol and triglycerides, probably due to the dietary fiber and SCFA in LAB. In addition, the ratio of low- and high-density lipoprotein was decreased in WBS, implying potential risk reduction for cardiovascular disease. An immunomodulatory assay of WBS revealed that pro-inflammatory cytokines TNF-α and IL-6 were decreased, suggesting anti-inflammatory activity. Gluten degradation by fermentation and antioxidation activity of menaquinol/ubiquinol by gut microbiota also supported the anti-inflammatory activity of sourdough bread. Furthermore, some beneficial gut bacteria, including Akkermansia, Bifidobacterium, and Lactobacillus, were increased in WBS. In particular, Akkermansia has been associated with anti-inflammatory properties. Consequently, WBS has beneficial effects on health, including decreased glycemic index and cholesterol, increased mineral availability and absorption, anti-inflammatory properties, and establishment of healthy gut microbiota.

Does sourdough bread provide clinically relevant health benefits?

“…During sourdough fermentation, the dough is acidified to a pH less than 5.0, which solubilizes phytate salts of Fe 2+ , Mg 2+ and Ca 2+ while maintaining the activity of cereal phytases close to their optima ( 205–208 ). Improved bioacessibility after sourdough fermentation was confirmed by in vitro experiments ( 209 ). Consumption of sourdough bread increased mineral absorption in rats when compared to a diet based on yeast-fermented bread ( 210 ).…”

A Functional Bread Fermented with Saccharomyces cerevisiae UFMG A-905 Prevents Allergic Asthma in Mice

“…The existence of a gut–lung axis and the relationship between asthma and gut microbiota has already been reported [ 41 , 42 ]. Previous studies demonstrated that probiotics or sourdough can change the gut microbiota in humans and mice [ [43] , [44] , [45] , [46] , [47] ]. Thus, the administration of bread fermented with S. cerevisiae UFMG A-905 could have altered mice gut microbiota and, consequently, prevented asthma development.…”

Exploring the Nutritional Impact of Sourdough Fermentation: Its Mechanisms and Functional Potential

“…Kwon et al [112] Yeast-leavened white bread and sourdough bread, male C57BL/6 mice Mice fed with sourdough bread showed a diabeteslowering effect by decreasing the GI, owing to the existence of dietary fiber and SCFAs. Some useful bowel bacteria like Akkermansia, Bifidobacterium, and Lactobacillus were increased in mice in the sourdough bread-fed group.…”