Boron (B) is considered a prebiotic chemical element with a role in both the origin and evolution of life, as well as an essential micronutrient for plants, some bacteria, fungi, and algae. B has beneficial effects on the biological functions of humans and animals, such as reproduction, growth, calcium metabolism, bone formation, energy metabolism, immunity, brain function, and steroid hormones. In the future, naturally organic B (NOB) species may become promising novel prebiotic candidates. We included the most relevant works about NOB species, starting from our 30-year research experience. NOB-containing compounds have been shown essential for the symbiosis between different kingdoms. New insights into the essentiality of NOB species for healthy symbiosis between the human/animal host and the microbiota will determine the use of natural B-based nutraceuticals to target the colon (colonic foods). The mechanism of action (MoA) of NOB species is related to both the B signaling molecule [autoinducer-2–borate (AI-2B)], as well as the fortification of the colonic mucous gel layer with NOB species from the specific prebiotic boron-rich diet. Therefore, both microbiota and the mucous gel layer of the colon become the NOB species’ target. This paper reviews the evidence supporting the essentiality of the NOB species on the symbiosis between the microbiota and the human/animal host with the stated aim of highlighting the MoA and target of these species.