 Human gut microbiome appears to be involved in the regulation of metabolic processes, including digested food components, absorption of fat, metabolism of drugs, and conversion of indigestible foods or partially digested food ingredients to molecules that may signal physiological host mechanisms. The gut microbiome is a complex ecosystem of liquor or chime and microbiota. A change in that habitat may result in microbiota community shifts and consequential changes in brain-gut regulatory interactions. NM504 is a cobiotic formulation composed of 3 generally recognized as safe; GRAS food ingredients. One ingredient is a conventional prebiotic fiber. A second ingredient can be fermented but it also is included to change the viscosity of the biome while protecting the mucosal barrier. The 3rd ingredient is an antioxidant with poor bioavailability that alters the redox potential of the biome, selecting for some and against other microbiota growth. In a placebo-controlled double-blinded intervention this trial will investigate the effect of NM504 on the intestinal microbiota as well as markers of glucose regulation in 20 prediabetic adults. The intervention periods last 28 days. Examination of participants will happen at the beginning, weekly and at the end of intervention and will contain anthropometry; blood samples; fecal samples; oral glucose tolerance test; meal tolerance test; and scales to assess appetite, hunger, mood, and bowel habits. 