WASHINGTON (Reuters) - Two strains of bacteria are the key
to making beans flatulence-free, Venezuelan researchers
reported on Tuesday.
They identified two bacteria, Lactobacillus casei and
Lactobacillus plantarum, which can be added to beans so they
cause minimal distress to those who eat them, and to those
around the bean-lovers, Marisela Granito of Simon Bolivar
University in Caracas, Venezuela and colleagues reported.
Flatulence is gas released by bacteria that live in the
large intestine when they break down food. Fermenting makes
food more digestible earlier on.
Writing in the Journal of the Science of Food and
Agriculture, Granito and colleagues found that adding these two
gut bacteria to beans before cooking them made them even less
likely to cause flatulence.
They tested black beans, known scientifically as Phaseolus
"Legumes, and particularly Phaseolus vulgaris, are an
important source of nutrients, especially in developing
countries," Granito's team wrote in the report.
"In spite of being part of the staple diets of these
populations, their consumption is limited by the flatulence
Smart cooks know they can ferment beans, and make them less
gas-inducing, by cooking them in the liquor from a previous
batch. But Granito's team wanted to find out just which
bacteria were responsible for this.
When the researchers fermented black beans with the two
bacteria, they found it decreased the soluble fiber content by
more than 60 percent and lowered levels of raffinose, a
compound known to cause gas, by 88 percent.
They fed the beans to rats and then analyzed the rats'
droppings to ensure that the beans were digested and kept their
When pre-soaked in the L. casei, the beans stayed
nutritious and produced few gas-causing compounds, they
"Therefore, the lactic acid bacteria involved in the bean
fermentation, which include L. casei as a probiotic, could be
used as functional starter cultures in the food industry," the
"Likewise, the cooking applied after induced fermentation
produced an additional diminution of the compounds related to