New study published in Scientific Reports by Pirkola et.al:
Fermentation of dietary fiber by gut microbes produces short-chain fatty acids (SCFA), but fermentation outcomes are affected by dietary fiber source and microbiota composition. The aim of this study was to investigate the effect of two different fecal microbial compositions on in vitro fermentation of a standardized amount of oat, rye, and wheat breads. Two human fecal donors with different microbial community composition were recruited. Bread samples were digested enzymatically. An in vitro fermentation model was used to study SCFA production, dietary fiber degradation, pH, and changes in microbiota. Feces from donor I had high relative abundance of Bacteroides and Escherichia/Shigella, whereas feces from donor II were high in Prevotella and Subdoligranulum. Shifts in microbiota composition were observed during fermentation. SCFA levels were low in the samples with fecal microbiota from donor I after 8 h of fermentation, but after 24 h acetate and propionate levels were similar in the samples from the different donors. Butyrate levels were higher in the fermentation samples from donor II, especially with rye substrate, where high abundance of Subdoligranulum was observed. Dietary fiber degradation was also higher in the fermentation samples from donor II. In conclusion, fermentation capacity and substrate utilization differed between the two different microbiota compositions.
Read more here: https://doi.org/10.1038/s41598-022-26847-y
Prostate cancer is a common cancer form among men, and preventive strategies are needed. In vitro studies have shown that benzoxazinoids in rye may have beneficial effects in prostate cancers, however, human studies are missing.
In the present study published in Scientific Reports by Nordin et.al. a quantitative method for analysis of benzoxazinoids was established and the plasma levels in men with prostate cancer, that had undergone a whole grain/bran rye vs refined wheat intervention, were compared to their PSA levels. Benzoxazinoid metabolites were significantly higher after rye vs refined wheat consumption and four of the Benzoxazinoid related metabolites were inversely associated with PSA.
Read more here: https://doi.org/10.1038/s41598-022-08856-z
Updated: Jan 5
The Effect of Rye-Based Foods on Postprandial Plasma Insulin Concentration: The Rye Factor

CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=163723
Consumption of whole grain has been associated with lower incidence of type-2 diabetes, cardiovascular disease and their risk factors including improved glycemic control. In comparison with other whole grain products, rye bread has been shown to induce lower insulin response in the postprandial phase, without affecting the glucose response. This phenomenon has been referred to as the “rye factor” and is being explored in this review where we summarize the findings from meal and extended meal studies including rye-based foods.
Overall, results from intervention studies showed that rye-based foods vs. (wheat) control foods had positive effect on both insulin and glucose responses in the postprandial phase, rather than on insulin alone. Mechanistic studies have shown that the rye factor phenomenon might be due to slowing of the glucose uptake in the intestine. However, this has also been shown for wheat-based bread and is likely an effect of structural properties of the investigated foods rather than the rye per se. More carefully controlled studies where standardized structural properties of different cereals are linked to the postprandial response are needed to further elucidate the underlying mechanisms and determinants for the effect of specific cereals and product traits on postprandial glycemic control.
Read more here: https://doi.org/10.3389/fnut.2022.868938