Hippocrates stated that all disease begins in the gut, an exaggeration but he had a point. Inversely recovery can begin there too depending on the presence of 'good' bacteria. Homeopaths and other types of natural healers have known all along but it is only now that main stream 'scientists' are 'discovering' this.
Perhaps an exaggeration but the point is that health greatly depends on your gut microbiota conditions. It suffices to say that in the process of digestion and metabolizing there shouldn't be any toxins or substances that are of any hindrance and thus it is advised to stay away from nanoparticles like zinc oxide, cerium dioxide, and titanium dioxide. Check the food labels and avoid ingesting it, do your own follow up research and spread the word.