Fiber Fueled is a new book by Will Bulsiewicz, a young gastroenterologist who has embraced lifestyle medicine. His approach emphasizes the importance of the gut microbiome in controlling most aspects of health. Our genome is 99+% the same as everyone else’s but our microbiome is unique, created by inheritance and environment but mainly what we eat.

In general the more diverse the microbiome the better. This diversity is fueled by fiber and micronutrients in our food. Not only do we need lots of fiber but we must have maximum diversity in our whole plant foods and whole grains to create a wide spectrum of gut flora controlling our health. Bulsiewicz’s goal is thirty different whole plant foods a week. I tried for this goal and found I could easily do 30 in a day using different nuts and seeds, a variety of sprouts, beans, fruits and vegetables. He explains the mechanisms whereby whole plant foods change the bowel flora and goes through scientifically demonstrated benefits in various conditions. His explanation for the value of organic foods is the importance of bacteria which are destroyed by non-organic farming. A quick wash gets rid of most pathogenic bacteria; those remaining are beneficial in creating a biodiverse, healthy gut flora.

The author’s experience was very similar to mine: very little training in lifestyle in medical school, residency and fellowship; study of scientific literature which offers volumes of irrefutable evidence for a WFPB diet; personal weight loss, more energy, fewer minor illnesses; a feeling of well being. He approached dietary change gradually. Deb and I did it quickly. All three of us soon realized that we didn’t want the unhealthy foods any more.

He explains the difference between celiac disease, true allergy and food sensitivities like FODMAP, excess gas from legumes and irritable bowel aggravated by certain foods. Most Americans have a poor bowel flora which is unable to handle many foods because we have not developed the necessary bowel organisms. The solution is desensitization with gradual introduction of small quantities of many healthy foods building tolerance with the development of a diverse, health gut flora. The book offers an elaborate, step by step, 28 day introductory diet to accomplish this.

Fiber Fueled is well referenced and acknowledges the work of many scientists and clinicians. My only major complaint is lack of mention of Denis Burkitt whom I have discussed in a prior blog. Burkitt’s biography was entitled The Fibre Man since he spent the last decades of his incredible career lecturing at medical schools and to physician groups about his observations in Africa documenting the critical role that the fiber from whole grains, fruits and vegetables plays in our health.