Fermented Vegetables as Vectors for Relocation of Microbial Diversity from the Environment to the Human Gut

Abstract

The discovery of yeasts as living cells able to produce ethanol in fermented foods and beverages in the 1920s continues to captivate our imagination with respect to the functionality and role of microbes in food preservation and human health. Mounting evidence confirms the ability of microbes to deliver nutrition, flavor and many bio-functionalities to fermented foods and the gastrointestinal (GI) tract of mammals. The microbial diversity found in fermented foods, particulalrly vegetables, can benefit the human GI tract microbiome. Critical functions for microbes associated with fresh vegetables include the contribution to growth, development and defense of host plants. In parallel, plants have evolved to select and maintain beneficial microbes, including those within their tissue. Fermentation then serves as an instrument to pre-adapt beneficial microbes indigenous to fresh vegetables to the acidic pH and high lactic acid concentration characteristic of the colon and to the metabolism of dietary fiber, particularly pectic substances naturally present in the plant material and the gut. Fermented vegetable products enjoy a long-lasting record of safety upon consumption and are an appropriate vector for the translocation of microbial diversity from plants to the gut. Fermented vegetables can enhance prebiotic fiber and beneficial microbes content and consequently augment the catalog of metabolic functions needed in and available to the gut for building resilience in a healthy individual. It is the indigenous microbiota of fermented vegetables and intrinsic chemical composition of substrates, particularly dietary fibers, which can enable beneficial health claims from the consumption of pickles.