In the late 1990’s, Dr. Zhao Liping, a Chinese scientist, reported that with a waist size of 43 inches and a weight increase from 132 to 176 pounds, he wondered if there was a link between his digestive microbiome, which is the collection of bacteria, viruses and fungi, both good and bad, that live in our digestive tract, and his weight gain.
Because of his background in microbiology, he had a theory that by manipulating his own digestive microbiome, he could improve his digestive and overall health. Inspired by research carried out at Washington University School of Medicine, which showed a link between obesity and gut bacteria in mice, in 2006, he decided to begin experimenting on himself by eating certain Chinese fruits and vegetables that were fermented prebiotic foods.
When he combined these prebiotic foods with a whole grain diet, he lost over 40 pounds of excess body weight in two years. His blood pressure and cholesterol levels also improved. He identified a good bacteria in his gut that had anti-inflammatory properties and which multiplied in his intestines to a degree reducing the percentage of bad bacteria in his gut. He and others have dedicated their research careers to pursuing ideas and data that will improve our understanding of the gut microbiota and its relationship to health and disease in human beings.
Therefore, is diet the most important factor that determines our health? It is well documented that Seventh Day Adventists who eat a predominantly vegetarian diet, have low rates of cardiovascular disease compared to the American population at large. In addition, their life expectancy is five to seven years longer than the average American. In the book, “The China Study,” it is proposed that low rates of heart disease and cancer in the rural Chinese population are due to a very low intake of animal protein compared to the western world.
Contrast this with health outcomes of the Pima Indian tribe in Arizona, who has the highest prevalence of Type 2 diabetes in the world. Researchers have determined this is predominantly caused by genetic factors, and to a lesser extent diet of the tribe members.
In conclusion, it seems most likely that our own health outcomes are determined by a combination of our personal dietary habits as well as genetic and environmental factors. We should expect to be learning more about how to make our gut microbiome healthier as more researchers like Liping advance knowledge in the near future in this important area.
Dr. Mark Roth writes about internal medicine for the Cleveland Jewish News. He is an internal medicine physician with University Hospitals.