When the phrase "good bacteria" is used, the majority of Americans instantly think of yogurt as the one source that they can identify in their diets. For people in other parts of the world and going back thousands of years, a variety of other fermented foods have served the important function of providing healthy bacteria to boost digestive and immune function.
Tempeh
Tempeh is a type of fermented soy product that originated in Java, where it is a staple protein source. It is made from fermented soybeans that are pressed into a cake form. Tempeh is a good source of probiotics and has been studied to determine the precise health benefits of its probiotics and fermentation products. One such study, published in the 2010 "Journal of Agricultural and Food Chemistry" identified components in tempeh that protected intestinal cell walls against attachment of pathogenic E. coli bacteria and, as a result, conferred protection against E. coli-related diarrhea. The researchers identified arabinose -- a compound derived from the cell walls of soy cells during the fermentation process -- as the active component of tempeh.
Miso
Miso, a traditional Japanese food, is a thick, salty paste made from fermented soybeans, barley or rice and used as a condiment to flavor other foods or made into soup. The fermentation process may take weeks or even years, depending on the particular variety, and according to the website BodyEcology.com, the healthiest miso is fermented for six months to two years, after which the levels of healthy bacteria begin to decline. Antioxidant and anticancer effects of miso were evaluated in a study in the 2006 "Journal of Nutritional Science and Vitaminology." The study found the free radical-scavenging and anticancer ability of an alcohol extract of miso to be superior to a water extract.
Sauerkraut
It is possible to make sauerkraut from nothing but cabbage and salt, with the bacteria present in the ambient air as the source of fermentation starter. Sauerkraut contains a variety of beneficial bacteria, some of which produce conjugated linolenic acid -- a compound known to have significant anticancer properties. A study published in the 2009 "Journal of Food Science" sought to identify bacteria from natural sauerkraut products with the ability to produce high levels of conjugated linolenic acid. The highest levels were obtained from a strain of Lactobacillus that had a 26-percent efficiency rate of converting linoleic acid into conjugated linoleic acid.
References
- PubMed: Identification of lactic acid bacterial strains with high conjugated linoleic acid-producing ability from natural sauerkraut fermentations.
- PubMed: Chemical components, palatability, antioxidant activity and antimutagenicity of oncom miso using a mixture of fermented soybeans and okara with Neurospora intermedia.
- PubMed: First characterization of bioactive components in soybean tempe that protect human and animal intestinal cells against enterotoxigenic Escherichia coli (ETEC) infection.
- Body Ecology: Miso Soup: A Delicious Bowl of Health and Anti-Aging Power
