Dr. Raphael Kellman’s book, The Microbiome Breakthrough: Harness the Power of Your Gut Bacteria to Boost Your Mood and Heal Your Body, was the topic of discussion at the latest San Jose Registered Dietitian Nutritionist’s Book Club meeting. The book outlines the fundamental connection between the brain, gut, thyroid and microbiome and provides a diet and lifestyle program to relieve suffering from depression, anxiety and other mood disorders. 

The microbiome is the community of bacteria that lives in the gut and elsewhere on the body. The book claims if any one part of this system is malfunctioning, it will impact the others. The book explains in simple terms how the brain works and how, through diet and supplements, the microbiome can improve brain function. 

The four-week protocol includes:

• A menu plan with recipes
• A supplement protocol, including multiple probiotics
• Strategies for supporting the health of the thyroid
• Activating the will for wholeness 

By treating the whole person, Dr. Kellman indicates that his clinic sees very positive outcomes with patients feeling significant relief from illnesses such as anxiety, depression and brain fog. Note that brain fog isn’t a medical condition; it’s a term used for certain symptoms such as feeling confused or being unable to organize thoughts into words.  

Areas of Agreement

• Food choices influence health. Gut microbes and the brain impact each other through the vagus nerve.
• Eating whole, organic foods that are rich in fiber and nutrients while avoiding ultra-processed foods high in fat, sugar and salt improves the nutritional quality of the diet and how a person feels. The lists of high-fiber foods with natural prebiotics and fermented foods rich in probiotics found in this book are especially helpful.
• Looking at the body holistically improves outcomes.
• Wellness practices that include physical activity, meditation, yoga and affirmations will improve both mental and physical well-being. 

Where We Differ

• Following this dietary pattern, even for just 28 days, would be very expensive (e.g., all foods should be organic, and animal foods should be pasture-raised) and may not be affordable for lower income communities. Also, the diet plan includes cooking three meals a day, which may not be realistic for a person who works and has family responsibilities.
• Some claims in the book oversimplify how digestion and metabolism work. For example, “Since the brain is composed primarily of fat, you need healthy fats to support the brain” is not a commonly accepted rationale for eating healthy fats. This would be like saying a person needs to eat fleshy meats to support muscle functioning, which is not true. 
• There is no body of scientific evidence that supports the benefits of sheep and goat fermented dairy foods over cow-based yogurts and cheeses. Trials of probiotic-containing fermented dairy foods like yogurt and cheeses such as cheddar, cottage, Gouda and mozzarella demonstrate benefits on weight control and type 2 diabetes management; the impacts on brain health are still emerging.

Bottom Line

Nutrition science as it relates to both the microbiome and the impact of nutrition on mental health is very preliminary at this time, and many of the studies that show positive impacts have only been done with animals. Though this dietary plan is based on emerging scientific evidence and there are health benefits to eating more prebiotic- and probiotic-rich foods, the rigorous protocol outlined in the book is too restrictive for most people. 

What is supported by the current level of evidence? Western dietary habits that include heavily processed foods, large quantities of refined grains and soft drinks, and little to no fresh produce increase the risk of mood disorders like depression and anxiety. Health-enhancing dietary patterns that benefit the whole body, including the brain, are based on minimally processed, bioactive foods like yogurt, non-starchy vegetables, beans, legumes, fruits, whole grains, nuts, seeds, fish and plant-based oils.  

Note: we strongly agree with the book author's cautions to check with your personal health care provider before starting this regimen and do not change any medications with medical supervision.

To learn more from registered dietitian nutritionists on timely nutrition topics, subscribe to the Let's Eat Healthy Ask a Nutritionist video series.

References

Cruz, J. Brain health: probiotics — big brain boost or just hype? Today's Dietitian. 2018;20(12). https://www.todaysdietitian.com/newarchives/1218p8.shtml. Accessed March 2, 2020. 

Ebner S, Smug LN, Kneifel W, Salminen SJ, Sander ME. Probiotics in dietary guidelines and clinical recommendations outside the European Union. World J Gastroenterol. 2014;20(43):16095-16100. doi:10.3748/wjg.v20.i43.16095.