By: Camryn Murray, Winthrop University Nutrition Student
Have you ever wondered why people refer to their stomach as their “second brain?” This
probably has something to do with something called the gut-brain axis.
What is the gut-brain axis?
The gut-brain axis is the common name for communication between the digestive system and the
central nervous system. The connection between the two is not completely understood within the
scientific world, but evidence suggests that the condition of our digestive health can significantly
impact our mood, sleep, brain, and overall health. Scientists believe that this connection has a lot
to do with the balance of bacteria in our intestines, which is referred to as our gut microbiota.
Where is our gut microbiota?
When people say, “gut health” or “gut microbiome,” they are most often referring to the bacteria
in the large intestine, specifically the cecum. Most of our food is digested and absorbed in the
small intestines but the large intestine finishes up the process by digesting and absorbing water, salts, and short-chain fatty acids that come from fiber. An imbalance between “good” bacteria and “bad” bacteria is called dysbiosis and is a phenomenon that is believed to affect overall health due to the gut’s relevance in almost every other body system.
Some ways dysbiosis can affect us:
Mood: Several neurotransmitters, like serotonin, dopamine, or GABA, is produced by the gut microbiome. Serotonin is known as the “happiness hormone,” and is important for regulating mood. Research shows that about 90% of serotonin is produced from bacteria like Lactobacillus, Bifidobacteria, Enterococcus, and Streptococcus in the gut.
Chronic disease: Research shows that patients with multiple sclerosis, Alzheimer's disease, Parkinson’s disease, and other mental health conditions have dysbiosis in their gut.
Stomach issues: The bacteria in our intestines release a lot of chemicals and gas, so imbalances in our microbiome can lead to bloating, discomfort, and even conditions like irritable bowel syndrome.
How can we promote bacterial diversity in our gut?
To try and avoid dysbiosis, we can do a few things to promote diversity in the types of bacteria
in our digestive system:
Get adequate sleep and physical activity
Eat a diverse, balanced diet, and don’t forget your fruits or vegetables! According to the 2016 American Gut Project, the #1 predictor of gut health is the diversity of plants in our diet
Eat enough fiber; try swapping refined grains for whole grains
Try some fermented foods like kimchi or kombucha
Surprisingly, some research shows an association between better gut health and owning a dog as a child, possibly because dog owners are more often outdoors with their dogs
Try to avoid being “too clean,” as a hyper-sterile environment and anti-bacterial sprays could reduce bacteria diversity (another possible reason why pets can be good for gut health)
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