Medical News Today: Common foods alter gut bacteria by influencing viruses

Of the 28 candidates, 11 compounds produced levels of virus particles at a rate higher than the controls, which signifies that they influenced phage activity.

Some of the most significant phage boosts occurred in the presence of clove, propolis (a compound produced by bees), uva ursi (also known as kinnikinnick or bearberry), and aspartame.

The most potent prophage inducer was stevia, which is a plant-derived sugar substitute. With some species of the bacterial strains, stevia increased the number of virus particles by more than 400%.

Conversely, some foods reduced the number of virus particles; most notably, these included rhubarb, fernet (a type of Italian liquor), coffee, and oregano.

To complicate matters, some compounds boosted phage activity associated with some bacteria, but reduced phage activity related to others; these compounds include toothpaste, grapefruit seed extract, and pomegranate.

According to the authors, one of the most potent antibacterial foods was hot tabasco sauce, which “reduced the growth of all three [gastrointestinal] species, except the opportunistic pathogen P. aeruginosa, by an average of 92%.”

Tabasco contains vinegar, but when they tested vinegar alone, it only reduced bacterial growth by 71%. They believe that capsaicin — the spicy compound in chilis — may explain the additional antibacterial capabilities. However, in the experiments with tabasco, no virus particles were found, so phages are unlikely to be involved.