Gut Health: Making Sense of the Microbiome

Gut Health: Making Sense of the Microbiome

What do you think of when you think of your gut? Perhaps you think it’s just a long tube that winds its way from your mouth through your stomach and then out through your intestines; however, that’s not the case. The gut, or gastrointestinal (GI) tract, is a complex dynamic biological community featuring trillions of microorganisms interacting in what is known as the microbiome.

What Exactly is Your Microbiome?

The human microbiome is a gathering of microorganisms that include bacteria, fungi, parasites, and viruses that live together on and in the body with many of those organisms taking up space all along the GI tract.1 While each person has a unique microbiome, one aspect of the microbiome remains consistent among everyone: the health of the microbiome supports wellness way beyond the borders of the GI tract. 

Brain, Heart, and Immunity

In the scientific literature, the connection between the gut and the brain is called the gut-brain axis and it has been studied more extensively over the past couple of decades. As it turns out, those bacteria, fungi, parasites, viruses, and other “bugs” that inhabit the microbiome can positively or negatively influence brain function including our mental health.2

When the gut microbiome is out of balance, it can also influence heart function. For example, research shows that if there are not enough good bugs and too many bad bugs, a situation known as dysbiosis, heart function can be negatively impacted.3 New research even shows that the heart-healthy benefits of walnuts likely come from the gut.4

The immune system probably receives the most benefit from a balanced microbiome because it’s estimated that 70-80% of immune cells live in the gut. Because of this, all those bugs interacting in the gut can help support immune function.5

Supporting Your Microbiome 

The good bacteria that live in your microbiome community are known as probiotics and when you take these probiotics as a dietary supplement, they can help support bacterial balance throughout the microbiome.6

Saccharomyces boulardii (S. boulardii), which is derived from yeast, is a probiotic that has been widely studied. The health-supporting benefits of this probiotic yeast have been evaluated in human double-blind clinical studies, which is considered the gold standard of research.7

Eating probiotic-containing foods can also help nourish your microbiome. Some examples of probiotic foods are yogurt, kefir, miso, natto, tempeh, and most kombuchas.8

Now that you know gut health is incredibly important for whole body health, learn why the Mediterranean Diet is better than other diets. And don’t forget to follow @zhou_nutrition for more fitness and wellness tips!


  1. Berg G, Rybakova D, Fischer D, et al. Microbiome definition re-visited: old concepts and new challenges. Microbiome. 2020;8. 
  2.  Schachtle MA, Rosshart SP. The microbiota-gut-brain axis in health and disease and its implications for translational research. Front Cell Neurosci. 2021;15.
  3.  Anderson KM, Ferranti EP, Alagha EC, et al. The heart and gut relationship: a systematic review of the evaluation of the microbiome and trimethylamine-N-oxide (TMAO) in heart failure. Heart Fail Rev. 2022;27(6):2223-2249.
  4.  Lamontagne ND. The heart benefits of walnuts likely come from the gut. American Society for Biochemistry and Molecular Biology. 2023;March 25. 
  5.  Wiertsema SP, van Bergenhenegouwen J, Garssen J, Knippels LMJ. The Interplay between the Gut Microbiome and the Immune System in the Context of Infectious Diseases throughout Life and the Role of Nutrition in Optimizing Treatment Strategies. Nutrients. 2021;13(3):886.
  6.  Wang X, Zhang P, Zhang X. Probiotics Regulate Gut Microbiota: An Effective Method to Improve Immunity. Molecules. 2021;26(19):6076.
  7.  Hossain M, Afrin S, Humayun S, et al. Identification and growth characterization of a novel strain of Saccharomyces boulardii isolated from soya paste. Front Nutr. 2020;7.
  8.  Marco ML, Sanders ME, Ganzle M, et al. The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on fermented foods. Nature Reviews Gastroenterology & Hepatology. 2021;18:196-208.