Microbe diversity is associated with different diets, with dietary change of as little as four days capable of affecting the gut microbiota.2,6

Diets considered healthy and which support a high microbial diversity have a predominance of fruits and vegetables, fibre, plant-derived protein, monounsaturated fatty acids (MUFAs), and omega-3 fatty acids (n-3 polyunsaturated fatty acids or n-3 PUFAs). High fibre diets correlate to levels of Prevotella, Bifidobacteria and Lactobacilli, while high carbohydrate diets correlate to Methanobrevibacter, Prevotella and Candida.

Low SCFA levels and reduced microbial diversity can arise when meat and animal-derived protein, saturated fats, refined carbohydrates, sugars, salt, alcohol and corn-derived fructose predominate. Adverse effects include bowel inflammation, a reduced mucosal layer, increased intestinal permeability and increased risk of pathogen infection.6

Increased bile secretion due to a high-fat diet can also raise bile-tolerant microbe levels which in turn may be associated with gastric pain as well as bowel inflammation.