Is sourdough bread healthier than regular bread?

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1. 1

   Nutritional benefits of sourdoughs: A systematic review

   Advances in Nutrition (Ribet et al.)Published Dec 15, 2022Checked Sep 30, 2026

   “A total of 573 articles were retrieved and investigated, of which 25 clinical trials met the inclusion criteria. The 25 clinical trials included a total of 542 individuals. The main outcomes investigated in the retrieved studies were glucose response (N = 15), appetite (N = 3), gastrointestinal markers (N = 5), and cardiovascular markers (N = 2). Overall, it is currently difficult to establish a clear consensus with regards to the beneficial effects of sourdough per se on health when compared with other types of bread because a variety of factors, such as the microbial composition of sourdough, fermentation parameters, cereals, and flour types potentially influence the nutritional properties of bread. Nonetheless, in studies using specific strains and fermentation conditions, significant improvements were observed in parameters related to glycemic response, satiety, or gastrointestinal comfort after bread ingestion. The reviewed data suggest that sourdough has great potential to produce a variety of functional foods; however, its complex and dynamic ecosystem requires further standardization to conclude its clinical health benefits.”

2. 2

   Does sourdough bread provide clinically relevant health benefits?

   Frontiers in Nutrition (D’Amico et al.)Published Jul 20, 2023Checked Sep 30, 2026

   “The latter potentially reduces their harmful effects, but depends strongly on the composition of sourdough microbiota, processing conditions and the resulting acidification. Tolerability, nutritional composition, potential health effects and consumer acceptance of sourdough bread are often suggested to be superior compared to yeast-leavened bread. However, the advantages of sourdough fermentation claimed in many publications rely mostly on data from chemical and in vitro analyzes, which raises questions about the actual impact on human nutrition. This review focuses on grain components, which may cause adverse effects in humans and the effect of sourdough microbiota on their structure, quantity and biological properties. Furthermore, presumed benefits of secondary metabolites and reduction of contaminants are discussed. The benefits claimed deriving from in vitro and in vivo experiments will be evaluated across a broader spectrum in terms of clinically relevant effects on human health. Accordingly, this critical review aims to contribute to a better understanding of the extent to which sourdough bread may result in measurable health benefits in humans.”

3. 3

   Effects of sourdough and yeast fermented breads consumption on glycaemia in healthy populations: a systematic review.

   Frontiers in nutrition (Starowicz et al.)Published Aug 4, 2026Checked Oct 4, 2026

   “Our objective was to evaluate the evidence for a positive effect of fermented bread consumption on glycaemia and insulinaemia in healthy adults. To this end, we conducted a systematic review to identify and analyze relevant human studies, complemented by a characterization of the breads investigated and a discussion of possible mechanisms of action, following the EFSA dossier framework. We identified 27 studies that met our inclusion criteria. Taking into account the risk of bias in these studies, the consistency of the reported effects, and the biological plausibility based on food characteristics and potential mechanisms of action, we conclude that the available evidence for a beneficial effect of sourdough compared to yeast-fermented bread on glycaemic and insulinaemic homeostasis in healthy individuals is neither sufficient nor convincing. For the general effect of fermentation on glycaemic and insulinaemic homeostasis in healthy individuals, evidence is considered very low.”

4. 4

   Effects of sourdough- or regular-bread fermentation, and phytate reduction on iron bioavailability, absorption, and iron status in humans: a systematic review of intervention studies.

   Frontiers in nutrition (Nikolaou et al.)Published May 5, 2026Checked Oct 4, 2026

   “30 μg Fe/100 mL), while exogenous phytase increased iron absorption by 50% for ferrous sulfate and 61% for iron bis-glycine chelate. However, long-term trials did not improve, and in one case even decreased, ferritin and total body iron; specifically, in the low-phytate sourdough rye bread group, ferritin declined from 32 ± 7 to 27 ± 6 μg/L and total body iron from 6.9 ± 1.4 to 5.4 ± 1.1 mg/kg over 12 weeks. On the other hand, phytate reduction combined with iron fortification showed positive effects on haemoglobin or prevented iron depletion; in anaemic children, fermented amaranth bread increased haemoglobin [adjusted β = 8.9 g/L (95% CI: 3.5-14.3)] and reduced anaemia prevalence (32% vs. 56%) compared to control bread. Despite convincing mechanistic evidence that the sourdough-fermentation process in bread fabrication improves iron bioavailability, through reduction of phytate, no human studies address this research question with the appropriate control and study quality.Systematic review registrationosf.io/gzt8m.”

5. 5

   Sourdough (Wikipedia)

   WikipediaPublished Sep 29, 2026Checked Sep 30, 2026

   “Sourdough is a leavening agent containing naturally occurring yeast and lactobacillus bacteria. The term is used to describe bread baked with sourdough, while the sourdough itself is referred to as a starter. In addition to leavening the bread, the fermentation process produces lactic acid, which gives the bread its distinctive sour taste and improves its keeping qualities.”

6. 6

   Probiotics in the Sourdough Bread Fermentation: Current Status

   Fermentation (Akamine et al.)Published Jan 20, 2023Checked Sep 30, 2026

   “Sourdough fermentation is an ancient technique to ferment cereal flour that improves bread quality, bringing nutritional and health benefits. The fermented dough has a complex microbiome composed mainly of lactic acid bacteria and yeasts. During fermentation, the production of metabolites and chemical reactions occur, giving the product unique characteristics and a high sensory quality. Mastery of fermentation allows adjustment of gluten levels, delaying starch digestibility, and increasing the bio-accessibility of vitamins and minerals. This review focuses on the main steps of sourdough fermentation, the microorganisms involved, and advances in bread production with functional properties. The impact of probiotics on human health, the metabolites produced, and the main microbial enzymes used in the bakery industry are also discussed.”

7. 7

   Fermented Foods: Definitions and Characteristics, Impact on the Gut Microbiota and Effects on Gastrointestinal Health and Disease

   Nutrients (Dimidi et al.)Published Aug 5, 2019Checked Sep 30, 2026

   “Putative mechanisms for the impact of fermented foods on health include the potential probiotic effect of their constituent microorganisms, the fermentation-derived production of bioactive peptides, biogenic amines, and conversion of phenolic compounds to biologically active compounds, as well as the reduction of anti-nutrients. Fermented foods that have been tested in at least one randomised controlled trial (RCT) for their gastrointestinal effects were kefir, sauerkraut, natto, and sourdough bread. Despite extensive in vitro studies, there are no RCTs investigating the impact of kombucha, miso, kimchi or tempeh in gastrointestinal health. The most widely investigated fermented food is kefir, with evidence from at least one RCT suggesting beneficial effects in both lactose malabsorption and Helicobacter pylori eradication. In summary, there is very limited clinical evidence for the effectiveness of most fermented foods in gastrointestinal health and disease. Given the convincing in vitro findings, clinical high-quality trials investigating the health benefits of fermented foods are warranted.”