Optimize Your Gut Health for Improved Mood
By Dr Emily Wiggins & Dr Kelcie Rosendhal
The popular saying, “I have a gut feeling” may be more accurate than you think. It is estimated that almost 95% of our body’s serotonin is produced by bacteria in the gastrointestinal tract. Serotonin is one of our “happy hormones” and is greatly influenced by the gut microbiome.
Recent evidence suggests that the gut microbiome can influence neural development, brain chemistry, emotional behavior, pain perception and our stress response!
The Gut is our “Second Brain”
The human gut has been dubbed “the second brain”, as it is the only organ that has its own independent nervous system separate from the central nervous system (CNS). No, the gut cannot provide us with conscious thought, but it can influence our emotions and behaviors.
The GI tract’s local nervous system is called the enteric nervous system (ENS) and is connected to the brain via the vagus nerve, which relays signals from the ENS to the CNS.
The Role of Serotonin & Impacts on Gut Health
Serotonin is our “feel good hormone”. Low levels of this chemical are associated with depression, anxiety and autism.
Interestingly, most of our serotonin is produced by enterochromaffin (EC) cells in the gut. Gut microbes influence this process both directly and indirectly. These microbes produce the short-chain fatty acids butyrate and acetate, which directly fuels the EC cells to produce serotonin. Indirectly, gut microbes signal the central nervous system to produce more serotonin when needed.
The serotonin produced in the gut has both local and global effects in the body. Locally, serotonin helps to regulate peristalsis, the wave length motion that moves food down our GI tract during digestion.
It also helps to modulate gastric secretions and influences the perception of abdominal pain. Globally, serotonin levels modulate mood and our sense of well-being.
How can you best support healthy serotonin levels in the gut?
A quick answer is, make sure you are getting enough probiotics in your food or by supplementation daily.
A more holistic way to support serotonin production is to optimize your digestion and create optimal terrain where a healthy gut microbiome can thrive.
As a naturopathic physician I discuss digestion with most, if not all, of my clients. The vast majority of them complain of bloating, gas, belching, constipation and/or reflux following meals.
Although these symptoms are extremely common, they are not normal and a sign of suboptimal digestion. Poor digestion can be caused by a variety of factors including food sensitivities, low stomach acid and increased stress.
How to Improve Your Digestion & Feel Better
Digestion is a function of the parasympathetic, “rest and digest”, portion of the autonomic nervous system, or ANS. The ANS has two main branches, the parasympathetic branch and the sympathetic, or “fight or flight”, branch.
Back before the modern era, activation of the sympathetic nervous system allowed us to run away from predators. Nowadays, it’s in charge of our response to everyday stressors such as traffic, deadlines, etc.
When we are in a sympathetic state blood is shunted to our extremities, away from our digestive organs. We do not process food well while we are in this state which can lead to the symptoms discussed above.
Ways to support digestion:
Eating while you are relaxed can greatly improve your ability to digest foods. I recommend taking a few deep breaths and eating in a quiet space while you are stationary, relaxed and without distractions (yes, no screens).
Chewing your food adequately can also decrease your incidence of burps and bloat. Mechanically, chewing helps to break down large food particles into smaller pieces. This reduces stress on the esophagus. Chewing also increases saliva production which contains digestive enzymes necessary to break down your food. Food becomes more alkaline with increased chewing, resulting in less acid formation and less incidence of reflux.
Eating slower also allows you to avoid overeating. Ghrelin and leptin are our hunger hormones. Leptin mediates long-term regulation of energy balance in our bodies. It suppresses food intake and helps us regulate weight long-term. Ghrelin, also known at the “hunger hormone”, is a fast acting hormone, and is the reason why we feel hungry before a meal. There is somewhat of a delay in the brain receiving the message from our stomach and pancreas that the body has been fed and to reduce ghrelin levels. Thus if we eat too quickly we are more likely to overeat because our body’s message that it has been fed has not yet been received by the brain.
Water works with your digestive enzymes to further break down food. Adequate hydration softens stools and decreases the incidence of constipation. I typically recommend drinking half of your body weight in ounces of water daily. A one-hundred and forty-pound person would drink seventy ounces of water, for example. Please keep in mind that drinking this much water is contraindicated in some conditions including heart failure.
Food intolerances can have a large impact on digestive health. Although there are blood tests available to help determine possible food intolerances, an elimination diet is the gold standard. The most common intolerances I see in clinical practice are wheat (gluten), dairy and eggs. That being said, each body is different and elimination diets should be tailored to the individual. Removing suspected intolerances, as determined by patient history and/or a blood test, from the diet for a period of time and then reintroducing them systematically can provide valuable insight in how your digestion is affected by what you eat.
Another culprit of digestive complaints is low stomach acid, or hypochlorhydria. We need stomach acid to break down our food and release nutrients from that food. Hypochlorhydria can be caused by stress, medications like proton pump inhibitors, age, infections and is common in individuals who have undergone bariatric surgery.
An easy way to increase gastric acid secretion is by consuming bitters before a meal. Bitters are herbs that are just that, bitter. Bitters work by first locally stimulating sensory receptors in the mouth and throat, initiating digestion. Further down the digestive tract, they promote gastric acid secretions, including the release of digestive enzymes, from the pancreas, duodenum (the first part of the small intestine) and liver. Bitters stimulate smooth muscle in the stomach to increase gastric emptying and cause the lower esophageal sphincter to contract. This prevents reflux of food back up the esophagus.
Some commonly used bitter herbs include gentian, dandelion, arugula, radicchio and chicory. An easy way to implement bitters into your meal is to start it with a salad made of bitter greens.
Tinctures and teas can also be a great way to get your bitters in before meals, especially if you do not have access to bitter greens.
What does YOUR body need?
If you have questions about your digestion and what’s normal, or if you are not sure how to best support your body, reach out!
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References:
Yano et al. Indigenous bacteria from the gut microbiota regulate host serotonin biosynthesis. Cell. 2015 April 9; 161(2): 264-276. doi:10.1016/j.cell.2015.02.047.
Mawe, Gary M. and Hoffman, Jill M. Serotonin Signaling in the Gastrointestinal Tract: Functions, dysfunctions and therapeutic targets. Nat Rev Gastroenterol Hepatol. 2013 August; 10(8) 473-486. doi:10.1038/nrgastro.2013.105.
Terry, Natalie and Margolis, Kara Gross. Serotonergic Mechanisms Regulating the GI Tract: Experimental Evidence and Therapeutic Relevance. Handbook of Experimental Pharmacology. 2017; 239: 319-342. doi: 10.1007/164_2016_103.