Perhaps you’ve heard it said that there is a lot of practical religion in a loaf of good bread (1).
This couldn’t be more true. Everybody loves well made bread. That bread that melts in your mouth and goes down smooth.
It is my opinion that healthy, tasty bread is essential for health. Unfortunately, those who abandon grains in their diet, of which bread typically is a substantial part, may significantly reduce the health of their gut microbiome. For those who do not abandon grains, increasing numbers are lessening their use, especially the breads, for what is thought to be harms from gluten, or sugar spikes, or bread-induced weight gain. It’s clear to me that there has been an attack on our daily bread that we must get to the bottom of.
In studying the question of whether sourdough bread is healthier than commercial yeast bread, I’ve realized that a great deal of careful attention is needed to make a loaf of good bread.
Let’s get into it.
The use of natural yeast and lactic acid bacteria in bread has been around for many centuries. But in the 1800’s commercial methods of yeast making were introduced that gave a more uniform and predictable outcome with bread, had quicker proofing or fermentation times, and were thought to be safer. Unfortunately this limited the availability of the types of microbes to a few species (usually yeast). Because of convenience and predictability most people or bread manufacturers have used commercial yeast since then.
In the last few decades, however, because of the realization that we need much wider diversity of microbes in our gut for health, interest in older traditional methods of bread making that use back slopping (seeding a previous best batch into a new batch to optimize the yeast and bacteria for the next loaf of bread) have renewed. Interestingly, data on the composition of more than 1000 sourdoughs are known, which means a vastly larger number of species of bacteria and yeast are available. In Europe, the term sourdough is defined as containing lactic acid bacteria. In sourdough over 100 species of lactic acid bacteria and several dozen species of yeast have been isolated.
This paragraph from the book “How Fermented Foods Feed the Gut Microbiome” explains this issue well…
“A process called “backslopping”, in which a small portion of a previously successful fermentation is used to inoculate fresh substrate was used to generate starter cultures for future fermentations. However, these processes fell from favor in the nineteenth century concurrently with the rise in public interest and governmental regulations concerning food safety. Starter cultures for mass-produced fermented foods were subsequently required to be produced from defined GRAS microorganisms, triggering a systematic reduction of microbial diversity seeding the digestive tract. Recently, several landmark studies have highlighted the importance of a healthy gut microbiome leading to a renewed interest in more traditional (artisanal) methods of food fermentations.”
Unfortunately, studies show that while commercially prepared whole grain bread does have many health benefits, the commercial yeast breads may not have the same potential for health benefits that sourdough breads have, with one major caveat. And that’s this —Because multiple different species are present and because the starter has to be continually tended to, the potential for problems is higher if the baker does not tend to the details of keeping his sourdough starter healthy. On the other hand, if the baker does a good job keeping his sourdough starter healthy by making sure the right kind of organisms predominate in abundant numbers they can make tremendously healthy and tasty bread.
An ideal whole wheat sourdough bread can have the following benefits over commercially prepared whole what bread…
1. There may be less spiking of blood sugars and insulin levels after a meal (though more research is needed to confirm)
2. There is better breakdown of FODMAPs (non-absorbed sugars), which give abdominal bloating and pain to susceptible people, such as those with IBS. (Side note: this also depends on proofing time. Prolonged proofing times while avoiding overproofing will also significantly limit FODMAPs.)
3. Improved fermentation of multiple organisms has the potential for less allergenic, immunogenic and inflammatory wheat components. This means less risk for wheat allergies, for example.
4. If the dough ferments or proofs long enough to allow the pH to reach less than 4.5 and the starter is back slopped almost daily or at least 3-4 days per week, the toxic potential of gluten proteins is broken down better by activating proteases from lactic acid bacteria. This may reduce the risk of leaky gut and autoimmune potential, as well as improving protein peptide, and amino acid breakdown and absorption.
5. Phytates prevent absorption of certain nutrients and are common in certain plant foods if the foods are not baked/cooked and/or fermented right. Phytates are in wheat. For wheat, if the pH during proofing drops to less than 4.5, phytates in the wheat are degraded better thereby releasing numerous nutrients for absorption into the body including: zinc, iron, magnesium, calcium, and manganese. Sourdough often does this better than commercial yeast doughs.
6. There is typically less acrylamide (a cancer causing chemical) production in sourdough bread than in commercial yeast bread.
7. Sourdough bread has higher levels of resistant starch (a form of indigestible fiber) which increases healthy gut microbe output of short chain fatty acids such as butyrate. This improves the health of the gastrointestinal tract lining.
While commercial yeast breads are generally thought to be healthy and to a lesser degree ferment wheat to make it palatable and digestible for many people, there are a growing number of people who have a microbiome scarcity. This means they may have a harder time digesting commercial yeast breads. There is an urgent need for many highly skilled bakers who can guarantee an excellent starter with a wider variety of healthy microbes, who have the patience to engage in longer proofing times without over-proofing, thereby making yummy bread that is out of this world.
References:
1. Ellen White, Counsels on Diet and Foods, pp. 251, 316.
2. Whittington, H.D., Dagher, S.F., Bruno-Bárcena, J.M. (2019). Production and Conservation of Starter Cultures: From “Backslopping” to Controlled Fermentations. In: Azcarate-Peril, M., Arnold, R., Bruno-Bárcena, J. (eds) How Fermented Foods Feed a Healthy Gut Microbiota. Springer, Cham.
3. D’Amico V, Gänzle M, Call L, Zwirzitz B, Grausgruber H, D’Amico S, Brouns F. Does sourdough bread provide clinically relevant health benefits? Front Nutr. 2023 Jul 20;10:1230043.