A healthy gut 101
The gut, also known as the gastrointestinal (GI) tract, is responsible for digesting food and absorbing nutrients from the food we eat. The gut consists of several organs, including the mouth, esophagus, stomach, small intestine, large intestine, rectum, and anus. Each of these organs plays a specific role in the digestive process.
When we eat food, the digestive process actually starts in our mouth! We have enzymes in our saliva that help to start breaking down the food as we chew. It then travels down the esophagus and into the stomach, where it is broken down by stomach acid and enzymes. From there, it enters the small intestine, where the majority of nutrient absorption takes place. The small intestine is lined with tiny finger-like projections called villi, which help to increase the surface area for nutrient absorption. After passing through the small intestine, any undigested food or waste products move into the large intestine, where water is absorbed and the remaining waste is stored in the rectum until it is eliminated through the anus.
The gut is also home to trillions of microorganisms, collectively known as the gut microbiome. These microorganisms play an important role in gut function and overall health. They help to break down certain types of food that we can't digest on our own, produce vitamins and other important compounds, and help to regulate the immune system.
Fun fact! The gut and brain communicate! The gut-brain communication, also known as the gut-brain axis, refers to the bidirectional communication between the gut and the brain. This communication occurs via the vagus nerve, a long nerve that runs from the brainstem to the abdomen, as well as through other signaling pathways involving hormones and immune cells.
Research has shown that the gut and the brain are closely interconnected, and that the gut can have a significant impact on our mood, emotions, and cognitive function. For example, the gut microbiome produces a range of neurotransmitters and hormones that can affect brain function, including serotonin, dopamine, and cortisol. In fact, around 90% of the body's serotonin, a neurotransmitter that plays a role in regulating mood, is produced in the gut.
Serotonin is primarily produced in the gut by enterochromaffin cells, which are specialized cells that line the gastrointestinal tract. In fact, the majority of the body's serotonin is produced in the gut, rather than in the brain.
Serotonin is a neurotransmitter that plays an important role in regulating mood, appetite, and sleep, among other functions. In the gut, serotonin helps to regulate intestinal motility and secretion, and is involved in the signaling pathways that regulate pain and inflammation.
The production of serotonin in the gut is influenced by a variety of factors, including the composition of the gut microbiome, diet, and stress. In some cases, imbalances in gut serotonin levels have been linked to gastrointestinal disorders such as irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD).
The gut produces a variety of hormones that play important roles in regulating digestive function and metabolism. Here are some examples:
Gastrin: Gastrin is a hormone that is produced by G cells in the stomach and duodenum. It stimulates the release of gastric acid, which helps to break down food.
Secretin: Secretin is produced by cells in the duodenum in response to the presence of acidic chyme (partially digested food) in the small intestine. It stimulates the release of bicarbonate from the pancreas, which helps to neutralize the acidity of the chyme.
Cholecystokinin (CCK): CCK is produced by cells in the small intestine in response to the presence of fat and protein in the chyme. It stimulates the release of bile from the gallbladder and pancreatic enzymes, which help to break down fats and proteins.
Glucagon-like peptide-1 (GLP-1): GLP-1 is produced by cells in the small intestine and colon in response to the presence of food. It stimulates the release of insulin from the pancreas, which helps to regulate blood sugar levels, and also plays a role in appetite regulation.
Peptide YY (PYY): PYY is produced by cells in the small intestine and colon in response to the presence of food. It helps to reduce appetite by signaling to the brain that the body is full.
Ghrelin: Ghrelin is produced by cells in the stomach and is known as the "hunger hormone." It stimulates appetite and plays a role in regulating energy balance.
While the gut does not directly produce sex hormones, there is some evidence to suggest that the gut microbiome may play a role in hormone regulation.
The gut microbiome can metabolize and modify certain hormones, including estrogens, androgens, and cortisol, which are produced by the body's endocrine system. For example, certain species of gut bacteria have been shown to produce an enzyme called beta-glucuronidase, which can increase the reabsorption of estrogen in the gut and lead to higher levels of circulating estrogen in the body.
Additionally, there is some evidence to suggest that the gut microbiome can influence the production of sex hormones indirectly by modulating inflammation and immune function. Chronic inflammation and immune dysfunction have been linked to hormone imbalances and conditions such as polycystic ovary syndrome (PCOS) and endometriosis.
The gut microbiome is incredibly diverse, and it is estimated that there are trillions of microorganisms living in the human gut. While the exact number of beneficial bacteria that colonize the gut can vary from person to person, it is generally believed that a healthy gut microbiome should contain a diverse array of bacterial species.
There is no one-size-fits-all definition of a "beneficial" bacteria, as different species of bacteria may provide different benefits depending on their function and interactions with the host.
However, an imbalance in the gut microbiome, known as dysbiosis, can have a negative impact on immune health. Dysbiosis can lead to an overgrowth of harmful bacteria, which can trigger an inflammatory response and weaken the immune system.
Research has also suggested that dysbiosis may be a contributing factor to a variety of autoimmune and inflammatory conditions, including inflammatory bowel disease (IBD), rheumatoid arthritis, and multiple sclerosis.
What happens when our gut health is compromised? When the gut is not functioning properly, it can lead to a variety of health problems. Some common gut-related issues include constipation, diarrhea, acid reflux, irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), and food intolerances or allergies. These issues can be caused by a variety of factors, including poor diet, stress, medications, and certain medical conditions. What about antibiotics? Most antibiotics work by targeting and killing the harmful bacteria that are causing an infection, but they can also inadvertently kill beneficial bacteria in the gut. It's estimated that it can take anywhere from a few days to several weeks for the gut microbiome to recover after a course of antibiotics, and in some cases, the microbiome may never fully recover to its pre-antibiotic state.
The gut and immune system are closely linked, and gut health can have a significant impact on immune health. Approximately 70% of the body's immune system is located in the gut, and the gut microbiome plays a crucial role in regulating immune function.
A healthy gut microbiome helps to support the immune system in several ways, including:
Preventing the growth of harmful bacteria: Beneficial bacteria in the gut help to prevent the growth of harmful bacteria, which can cause infections and other health problems.
Boosting the production of antibodies: The gut microbiome helps to stimulate the production of antibodies, which are proteins that help to identify and neutralize harmful pathogens.
Regulating inflammation: Chronic inflammation can contribute to a variety of health problems, including autoimmune disorders. The gut microbiome helps to regulate inflammation in the body, which can help to reduce the risk of these conditions.
Promoting healthy digestion: A healthy gut microbiome helps to promote healthy digestion and nutrient absorption, which can help to support overall health and immune function.
What are some other practical things we can do to help ensure our gut stays healthy? Eat a healthy, balanced diet: VARIETY! The bacteria in the microbiome love DIVERSITY. A diet that is rich in whole foods, including fruits, vegetables, whole grains, and proteins, can help to support the growth of beneficial bacteria in the gut. Fiber-rich foods in particular, such as leafy greens, nuts, and seeds, can help to feed beneficial bacteria and promote the growth of a diverse gut microbiome.
Stay hydrated: Drinking plenty of water and other fluids can help to support digestive health and prevent constipation.
Get regular exercise: Exercise has been shown to have a positive effect on gut health, helping to reduce inflammation and promote the growth of beneficial bacteria.
Reduce stress: Chronic stress can have a negative impact on gut health, so finding ways to manage stress, such as through meditation, yoga, or other relaxation techniques, can be beneficial.
Avoid antibiotics and unnecessary medications: Antibiotics can disrupt the balance of bacteria in the gut, so it's important to use them judiciously and only when necessary. Similarly, other medications such as proton pump inhibitors (PPIs) and non-steroidal anti-inflammatory drugs (NSAIDs) can also have a negative impact on gut health, so it's important to use them only as directed by a healthcare provider.
Consider taking a probiotic or prebiotic supplement: Probiotics are live bacteria that can be beneficial to gut health, while prebiotics are types of fiber that feed beneficial bacteria. Fermented foods are also good! Again Variety is key!
Get enough sleep: Sleep plays an important role in gut health, so getting enough restful sleep each night is important for maintaining a healthy gut.
We always want to restore health as much as possible through positive changes to nutrition and lifestyle. But we also know that sometimes some supplemental support can be very helpful. Here’s a few of our favorite products:
You also may want to check out our guide on stress for some additional info on managing stress for improved gut function.