1. A dietary supplement comprising a combination of four heterologous microbes consisting of Lactobacillus brevis, Lactobacillus plantarum, Leuconostoc mesenteroides, and Pichia kudriavzevii, wherein the combination of four heterologous microbes comprises at least 1×10 7 of each of the four heterologous microbes, wherein each of the four heterologous microbes comprises a gene or gene pathway directed to biosynthesis of short chain fatty acid (SCFA) or metabolites thereof and wherein the combination produces an increased amount of SCFA when grown together relative to the summed amount of SCFA produced by an equivalent amount of each distinct microbe grown in isolation under the same conditions, wherein the combination lessens a decrease in, maintains, or improves bone health in a subject, and wherein the dietary supplement is formulated for oral delivery.