5 Surprising Gut Health Facts A Gastroenterologist Wants You To Know

Gut health is intricately tied to the trillions of bacteria, viruses, protozoa, and fungi that live inside our intestines. Together, these germs make up the gut microbiome, a rich ecosystem with a metabolic capacity that exceeds that of the liver1. 

We know today that the gut microbiome plays a crucial role in immune function and inflammation2. Adequate exposure to the right quantity and quality of germs at birth and beyond leads to a balanced immune system, one that defends the body while avoiding overreactions to harmless food, germs, or other matter that may lead to autoimmune diseases. 

An imbalance in the microbiome, or dysbiosis, is tied to all kinds of chronic diseases, including heart disease3, cancer4, obesity5, diabetes6, autoimmune conditions7, and neurodegenerative ailments8. 

A dysbiotic microbiome is often an inflammatory one, with changes in the variety of microbial species, the chemicals they make, and the genes they stimulate. Inflammation may begin in the gut and weave through the body, contributing to illness.  

The most important food for the gut microbiome is fiber from a variety of whole plant foods, including fruits, vegetables, whole grains, legumes, and nuts. Gut microbes digest fiber and produce beneficial metabolites like short-chain fatty acids, which nourish the gut barrier, improve immune function and help to prevent inflammation. 

Unfortunately, at least 95% of Americans fail to meet the daily recommended dietary allowance (RDA) of fiber in the diet (38 grams for men and 25 grams for women). Meanwhile, optimizing gut health means going beyond RDAs. 

The more fiber you eat, the more you are able to cultivate beneficial, fiber-digesting gut bacteria and improve the overall diversity of species that make up the gut microbiome. A diverse gut microbiome is an important marker of gut health. 

While we need to include a good amount of whole plant foods in our daily diet, we also need to be mindful of the types of plants we are consuming. The most important factors in cultivating a diverse gut microbiome are both the quantity and diversity of whole plant foods. 

For example, seaweed contains important fibers for gut health that are not present in terrestrial plants. In one 2011 study of middle-aged adults, the diversity of fruits and vegetables9 consumed was a better predictor of lower inflammation in the body than the absolute quantity consumed. 

Each year, around a quarter of produce in the U.S. is thrown away for cosmetic reasons, including strange shapes and curves and minor blemishes, contributing to global food waste and climate change. But these so-called imperfect foods may be even more nutritious and adept at fighting inflammation than their attractive counterparts.