Red wine and coffee modulate the microbiome

Prebiotics are foods that alter the microbiome.  They are important to many potential microbiome therapeutics because they could be used to shift the microbiome from a dysbiotic, or unhealthy state, to a normal healthy state.  Most scientists that study prebiotics investigate indigestible fiber, because these are known to survive digestion are broken down by specific microbes, thus predictably selecting for specific organisms’ growth.  Recently though, other prebiotics are being studied.  A major class of these are polyphenolic compounds, which provide the antioxidant characteristics of plant material.  Last week researchers from Spain studied the shift in the microbiome that may be induced by red wine and coffee in particular.  They published their results in the journal Food & Function.

The researchers studied 23 patients that had allergic rhinosinusitis or asthma as well as 22 age-matched controls.  They chose individuals with autoimmune diseases because of the promise of prebiotics affecting their diseases.  They asked all of the individuals to fill out a food survey of what they had eaten in the past year, and how often they ate it.  After, the scientists took samples of their feces and measured the bacteria within it.  The scientists found that the abundance of Clostridium, Lactococcus and Lactobacillus was directly associated with polyphenol intake from coffee, and that Bacteroides was positively associated with red wine consumption.  Unfortunately, they noted that these did not differ between allergic people and healthy ones.

This study was certainly lacking in its scope and rigor.  It did not attempt any interventional studies to controllably reproduce these effects, and it did not identifiy specific polyphenols that are responsible.  Nonetheless, it does begin to define how alternative prebiotics may affect our microbiome.  Polyphenols in particular are linked to all sorts of health benefits, normally attributed to their anti-oxidation, however perhaps they positively impact the microbiome as well. 

Ingesting blueberries and oats may modulate the microbiome and help diabetics

Prebiotics are foods that are consumed in order to modulate the microbiome.  They are normally composed of molecules that are not broken down by our body itself, but rather that remain intact until making it to the large intestine where bacteria can break them down.  Common prebiotics come from plant materials, like long chained complex carbohydrates, as well as polyphenols, like blueberry extract.  In a recent study, scientists from Louisiana State University performed randomized dietary intervention on obese subjects and gave them a mixture of these molecules.  They then monitored the changes in the microbiome that occurred, along with changes in health indicators.  Their results were published in The Journal of Diabetes and its Complications.

The researchers included 30 adults in the study, and split them into two groups: one to receive the microbiome modulating dietary supplement, and the other to receive a placebo.  The dietary supplement included blueberry extract, oat bran cellulose, and inulin (a common oligosaccharide of fructose).  The subjects ingested the supplement daily for four weeks, with samples being collected once before and once at the end of the sudy.

Many positive health consequences were associated with eating the prebiotics.  Those patients had improved glucose tolerance, as well as increases in satiety.  The satiety may have been caused by an increase in fasting PYY concentration, a peptide known to cause hunger suppression, which was higher in those people taking the prebiotic.  In addition, there was an increase in self-reported flatulence from taking the prebiotic, but otherwise no adverse events were recorded.  Interestingly, there were no statistically significant changes in the microbiome that resulted from eating the supplement, however higher levels of short chained fatty acids (SCFAs) were observed in the stools of those patients.  Even though no statistically significant change was measured, it is quite possible that the level of sequencing depth and analysis was robust enough to truly observe changes that may have occurred.

This study is another that shows the benefits of eating prebiotics.  Interestingly, the prebiotic used for this study is the same one used by Microbiome Therapeutics in their metformin formulation.  This prebiotic, when combined with metformin, increases its efficacy for diabetics.  This study shows that possibly the prebiotic alone is responsible for this improvement, although it gets us no closer to explaining how this occurs.  Any of our readers that are taking metformin may want to read the wealth of literature around what Microbiome Therapeutics has done, because just the simple addition of foods to the drug seems to improve the results of taking it.