Baguette and sliced bread lovers, we’ve got good news for you! For years, it’s been criticized for its bad nutritional reputation and has been shunned as a mere glutinous slab lacking any health benefits, but white bread may help boost some of the beneficial gut microbes, according to a new paper recently published in the Journal of Agricultural and Food Chemistry.
It’s been known for decades that the close relationship between health and gut microbiota and that a healthy diet is essential for maintaining a balanced and rich population of gut bacteria. Up until now, a large number of studies had focused, precisely, on the effects of the food we eat on our gut flora, especially dietary fibre. In contrast, there was little to no information on other highly correlated diet components, such as polyphenols. A team of researchers from the University of Oviedo and the Spanish Research Council (CSIC) wanted to close that gap and set out to explore the association between gut microbiota composition and the intake of both fibres and polyphenols (common in much of what we consume like fruit, tea, spices, chocolate or wine) in a regular diet.
The researchers recruited thirty-eight healthy adults who were asked to answer a questionnaire on their food habits. Scientists also analysed the participants’ stool samples. Unexpectedly, they found that those individuals who ate more white bread had higher levels of Lactobacillus, a group of beneficial bacteria that could ward off digestive disorders, in their digestive tracts.
It seems that white bread provides soluble hemicellulose (dietary fibre) and resistant starch in the diet. Both products have been positively related to a higher presence of Lactobacillus in the gut. “The prebiotic effect of cereals has been traditionally attributed to whole grain foods, because of their high fibres content. However, our results reveal that the consumption of refined grains, often undervalued in this regard, could beneficially modulate intestinal microbiota too”, explained the authors of this research in a press release.
However, they also warned that it was difficult to pinpoint how much resistant starch comes from bread intake, or from the diet in general. They believe effects on gut microbiota that are often attributed to isolated fibres or even polyphenols might be modified by other components in food. “Although the limited sample size and high variability of individuals do not allow firm conclusions to be established, our study highlights the importance of considering diet as a whole, rather than isolated components”, authors considered. This means that, in their opinion, future research should be focused on the broader diet, rather than on individual compounds.