The Gut, Our "Second Brain"

In our last post we broke down the different components of the digestive system. Now let’s recap just how important a healthy digestive system is to our physical, mental, and emotional well-being…

Aside from the physical break down of food into nutrients, the gut serves as a communication center for the brain. There are more nerve endings surrounding the digestive tract than anywhere else in your body, including your spinal column. The gut and brain work together in the digestive process as well as playing key roles in our stress level, mood, and state of mind. A bi-directional system, the gut and brain inform one another of stressors to the body. The gut is filled with nerve cells from the Vagus nerve, which is directly responsible for control of heart rate, gut motility, sweating, and emotional stress. The gut also produces more than 90% of the body’s serotonin, a hormone that helps regulate our mood or emotions.  It’s no surprise, therefore, that the gut is also referred to as the “second brain.”

The digestive system is also the home of the “gut microbiome”—a diverse community of different bacteria types, viruses, and microbes. Research is providing evidence that this gut microbiome plays a vital role in both fighting disease and maintaining our health. In a review of the genetic diversity of the microbiota in the gut, each sample of microbes contained approximately 750,000 genes, 30 times the number of genes found in the human genome (Shreiner et al., 2015). They also found that the number of genes shared between individuals was relatively low, suggesting that each of us has his or her own unique “thumbprint.” Some gut bacteria, or some bacteria in excessive amounts, can cause infection, ailments, and even an increased risk for cancer. At the same time, other bacteria help us to fight disease and stay healthy.  Studies with scientists are continuing to evaluate the good and bad effects of gut bacteria.

Researchers published a study in the journal Nature (Cho et al., 2012), showing a potential association between antibiotic use, changes in gut bacteria, and an increased risk of obesity. In addition, doctors have begun using good bacteria to treat people who have a serious and potentially life-threatening infection, such as Clostridium difficile (C. diff) infection, when antibiotic therapy is no longer working. These findings suggest how vital a healthy and diverse microbiome is to overall health and well-being.

Tune in next week to learn how diet, nutrition, and lifestyle can contribute to a healthier gut and a healthier YOU.

Works Cited

Cho I, Yamanishi S, Cox L, et al. Antibiotics in early life alter the murine colonic microbiome and adiposity. Nature. 2012;488(7413):621-6.

Shreiner AB, Kao JY, Young VB. The gut microbiome in health and in disease. Curr Opin Gastroenterol. 2015;31(1):69-75.