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About Rodney Dietert, PhD
Rodney is Professor of Immunotoxicology at Cornell University in Ithaca, New York. He received his PhD in immunogenetics from the University of Texas at Austin. Among his authored and edited academic books are Strategies for Protecting Your Child's Immune System and Immunotoxicity, Immune Dysfunction, and Chronic Disease. Rodney previously directed Cornell's Graduate Field of Immunology, the Program on Breast Cancer and Environmental Risk Factors, and the Institute for Comparative and Environmental Toxicology, and he has served as a Senior Fellow in the Cornell Center for the Environment. Recently, he appeared in the 2014 award-winning documentary Microbirth. In 2015 he received the James G. Wilson Publication Award from the Teratology Society for the best paper of the year on the microbiome.
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Books Discussed in this Podcast
Interview Show Notes
02:70 Other Genomes Matter Too: We are made up of thousands of different species of organisms. Many are microbial. The majority of our genes come from these microbes. It influences our approach to diet, protection against environmental chemicals and toxicants, to preventative medicine and medical treatment in a way that takes those species into account. We have a stewardship opportunity.
04:48 Microbiome and Drugs: The study of toxicology is in a do-over, now beginning to include consideration the diversity of the microbiome.
06:57 Microbial Enterotypes: There is still much to learn, but there is enough information now to begin utilizing what we have learned about microbes. There are different enterotypes and they appear to be linked to the millennia of our ancestry. The enterotypes were shaped by the lifestyle and diet of our ancestors. It is probably easier to improve the health of your microbiome to move it within the enterotype rather than between enterotypes. With a healthier microbiome, beginning at birth, you have a better opportunity to prevent chronic disease.
08:43 Mother Child Microbial Transfer: The birth event is the most critical donation window. In utero babies are exposed to placental microbes, effecting the immune system. During vaginal delivery, the baby receives the majority of microbial seeding through the birth canal and skin to skin contact. If a child’s birth is not vaginal, the microbiome will come from the hospital environment. This impacts the immune system as well as brain and neurological systems. Physiology will mature differently. It translates to a higher risk of a number of different diseases and conditions, like obesity, type 1 diabetes, and asthma. There are alternatives for seeding non-vaginal births. Breastfeeding transfers microbes. Breastmilk contains components that cannot be digested by mammals. We now know that this is it is prebiotic, food for microbes, to help them grow and progress. Breastmilk also has immune boosting components. Formula does not account for the immune boosting, prebiotic or microbial transfer.
13:30 Rebiosis: Many of us try to shift our microbiome. We need to seed the microbes we want to grow. Prebiotics are the direct energy source for particular species of bacteria.
13:42 Immune Education: Physicians were taught that the immune system is fully mature at birth. The immune system at birth is not complete. The microbes and the immune system grow up together. The first few years is a critical window in which the immune system learns how to operate with the environment. If the microbes are not installed at birth and maturing with the immune system, the immune system never matures correctly and it will eventually misfire and initiate self-destruction. It can show up as allergic diseases, autoimmunity and inflammatory conditions. It is a probability, not a certainty.
15:56 Family Size and Microbiome Diversity: The entire earth is a microbial bubble. We each exist in a microbial bubble. If you are a member of a larger family and/or you have pets, you will receive a larger microbial transfer. This can be beneficial, but not always.
17:43 The Shared Microbiome of Mother and Infant: If a baby is seeded from a microbiome from a mother who has a number of chronic diseases, and nothing has been done to restore the mother’s microbiome, the baby will have a microbiome that reflects those chronic diseases. Dr. Dietert recommends rebiosis for all adults and especially pregnant women.
19:41 Rebiosis Strategies: There is no single strategy. Fermented foods from your ancestry are a good start. They help with microbiome maintenance. Probiotic supplements can be helpful, especially those that have a great number of species of bacteria. The strain and the genes that are being carried are important. Probiotic supplementation will soon apply to skin, mouth and nasal passages. FMT, fecal microbiota transplantation, has been successful for treating some recurrent infections. With FMT, the treatment is only as good as the donor. It can now be done by taking capsules. In the future, the donor will be tailored to the patient.
25:14 The Importance of Bacterial DNA: You have a flow through system. Even brief residency of probiotics can be beneficial. The hope is that they will take up residence where they belong and produce the metabolites you need when you feed them. What they are wearing on their surface, will interact with barrier cells and immune cells. These are the proteins and enzymes that bacteria are making coming from the genes. The genes are important. Sometimes we lack just a single critical species of bacteria.
28:35 Drug Metabolism: The difference between a drug being effective, ineffective or being toxic can depend upon the presence of one particular bacterial species. Doctors of the future will not prescribe drugs without knowing our microbiome profile.
30:23 Keystone Bacterial Species: Some species take care of the local environment. These keystone species thus influence the existence of other species. It is like marigolds in your garden as a pest preventative.
30:56 Influence of Fiber: Nothing is one-size-fits-all. Dr. Dietert is pro-fiber in general. Where fiber can be tolerated, it is a great option. Opportunities for other prebiotic foods exist.
32:28 Inflammation, Chronic Disease and Bacteria: Non-communicable diseases, now an epidemic, are viewed as individual diseases. Researchers work on them one disease at a time. We partition them. If you look at the underlying perturbances and the underlying features, of non-communicable diseases, they are connected by misregulated inflammation. Correcting inflammation may not be a magic bullet because permanent damage may have been done. Misdirected inflammation is reflected in the mistraining of the immune system. From as early as possible, diet and microbiome must work together.
37:54 Baby’s Immune System Control: T regulatory cells counterbalance Th17 that produce an interleukin 17 as one of their major products. Invariant natural killer T cells are also important. The relative sizes of populations are also important. The populations change greatly during a baby’s first year of life. A number of bacteria control this from their cell surface molecule as well as by what they secrete. Short chain fatty acids are important for immune, neurological health and other physiological systems. They control neural behavior and immune regulation, including T regs. It is not a single bacterial species, but a mix of species that are most important in presenting metabolites to the underlying immune cells that determine the mix of those populations. This determines whether a baby is well armed and balanced well for future health.
39:56 Microbiome Strategies for Older Folks: It is never too late to offset inflamaging, the inflammation that occurs with age. Rebalancing the microbiome is beneficial at any age. As Dr. Dietert researched and wrote about inflammation, he was unaware that he had systemic inflammation. He is in his sixties and has been able to make changes to his diet and microbiome to dampen the inflammation.
42:15 GMO Concerns: GMO foods have not been shown to be safe for the microbiome and need to be vetted. In soil microbes, there is evidence in the literature that GMOs present a hazard. It is a possibility that they a similar hazard to microbes within our bodies. Dr. Dietert steers clear of them.
44:48 Dr. Dietert’s Favorite Mineral/Nutrient: This is a difficult question. Magnesium is one of his “go to”s. It prevents cramps during physical activity and improves his metabolism. Astragalus is his favorite herb, with ginkgo a close second.
46:35 Dr. Dietert’s Morning Routine: Dr. Dietert had always worked on immune system and immunity in early life, but he did not work on the microbiome. He had been trying to write a paper on the one thing that can be done for an infant to ensure lifetime health, but he was stuck. One night in a dream the concept of the completed self, where the baby must self-complete with the microbiome, came to him. He trusted his gut instincts that it was what he needed to follow. Early mornings are often spent with an inspiration or idea and working them. It is when he does his best work. Dr. Dietert teaches a class at Cornell on creative tools for scientists that includes sleep-based problem solving. Many Nobel laureates keep a notepad or I-pad near their beds to record ideas that came to them in the night.
50:30 Dr. Dietert’s Elevator Pitch: Non-communicable diseases are the world-wide killer. We cannot afford it. By 2030 it will occupy 50% of global net worth. It is causing us to be more isolated, due to allergies, sensitivities and other health problems. There are solutions, but they are only effective when we treat the whole human, including the microbiome.