Diverse Diet + Diverse GI Microbiome = Better Health
The old adage, “You are what you eat”, is taking on a whole new meaning as research into the microbiome is uncovering the role that food components play in the gut microbiota and their impact on human health and disease. And one thing that has become most apparent, according to Mark Heiman, Chief Scientific Officer at MicroBiome Therapeutics, is that a diverse diet produces a diverse gastrointestinal (GI) microbiome, which leads to better health outcomes. Heiman was the Featured Lecturer on Monday afternoon and spoke on “Therapy for Gastrointestinal Microbiome-Associated Diseases Requires Dietary Diversity.”
While our genetics have not changed over the past 50 years, our food supply has become less diverse, said Heiman. About 75% of plant diversity has been lost to uniform, high-yielding varieties. And 75% of the world’s food supply is derived from only 12 plants and five animal species. Rice, maize and wheat contribute 60% of our calories from plants, noted Heiman.
Diet is the principal regulator of the GI microbiome, an ecosystem in our GI tract, comprised of trillions of bacteria (microbiota) in a solution of unabsorbed macronutrients and micronutrients. Like all ecosystems, a diverse GI microbiome is healthier than a homogeneous one, declared Heiman. In addition, the loss of dietary diversity shifts the microbiome to unhealthy states as observed by loss of GI microbiome diversity associated with metabolic diseases such as obesity, Type 2 diabetes, and GI disorders such irritable bowel syndrome and chronic constipation—all of which have increased in prevalence over the past five decades.
Heiman presented research on a GI microbiome modulator used to treat the microbiome of persons with prediabetes and Type 2 diabetes (T2D). The T2D microbiome is characterized by a decreased ability to produce short-chain fatty acids (SCFAs), increased GI and general inflammation, and an increased capacity to produce methane. Following 4 weeks of treatment with the modulator (which contained inulin, agave, beta glucan, oat, proprietary antioxidants, and blueberry), the test subjects exhibited postprandial glucose control, a healthy GI inflammatory response, better appetite control, and bowel movement regularity.
Combinations of specific food ingredients are a safe and effective approach to modulating the GI microbiome, stated Heiman.
In another experiment, Heiman sought to compare an obesogenic diet (obD) with a more diversified obesogenic diet including an activated soy pod fiber (obD+soy fiber) on mice. Following 4 weeks of treatment, the obD-fed mice showed about a 6-g weight gain while the mice fed obD+soy fiber gained only about 4 g. Remarkably, the obD-fed mice ate less food per day (2.8 g) than the obD+soy fiber-fed mice (3.1 g) at four weeks. Fecal mass was greater with the obD+soy fiber-fed mice, and included unabsorbed triglycerides, which may have implications for fatty liver diseases.
Supplementing the diet with the activated soy pod fiber protects the colon from inflammation, increases SCFA production (prebiotic effect), increases fecal loss of fat and glucose, and shifts abundances of some GI microbiota species, concluded Heiman.