Rye bread, which originated in present-day eastern Turkey, is one of the healthiest bread options on the market, as it is rich in vitamins and minerals. To add to the benefits of rye bread, a new study has shown that lactic acid bacteria and gut bacteria are another health benefit.
Impact on insulin metabolism
The study, published in Microbiome was conducted by the University of Eastern Finland, used a metabolomics approach in order to analyse metabolites found in food and the human body. The effects were studied in mice and an in vitro gastrointestinal model, which mimicked the function of the human gut.
Using the two models, the researchers were able to eliminate naturally occurring differences in the gut microbiome between different individuals, which made it easier to detect metabolites which originated from rye. Rye sourdough, used when baking rye bread in particular was found to be rich in lactic acid bacteria.
Improves blood sugar levels
The bacteria modify bioactive compounds found in rye and are used to ferment the dough, which creates branched-chain amino acids and amino acid-containing peptides, known to have an impact on insulin metabolism.
Compounds found in rye are processed by gut bacteria before they are absorbed by the body. In the study, it was found that gut microbes and the microbes found in sourdough produce compounds that are quite similar.
An earlier study by the same research showed that derivatives trimethylglycine or betaine, which is also found in rye, reduces the need for oxygen in heart muscle cells, which may protect the heart from ischaemia or possibly even enhance its performance. This explains why rye improves blood sugar levels and lowers the risk of cardiovascular disease.
Although the health benefits of rye bread have been known for a while, it is not clear why rye lowers insulin resistance compared to other breads such as whole wheat or why it lowers blood sugar. A researcher in the study, Ville Koistinen from the University of Eastern Finland, noted that "the major role played by microbes in human health has become more and more evident over the past decades, and this is why gut microbes should be taken care of. It's a good idea to avoid unnecessary antibiotics and feed gut microbes with optimal food – such as rye."
Image credit: iStock