BY Trevor Murphy MS3, Samuel Mathis, MD, MBA
In recent years, gut health has garnered significant attention—and for good reason. The gastrointestinal tract plays a crucial role in digestion and influences our mood and overall well-being. Our gut health is predominately determined by our intestinal microbiome. The proportion of “good” vs “bad” gut bacterial can have significant impacts on our health. Lately, more attention has been given to terms that were originally designed to describe integrative complaints. Terms like “leaky gut syndrome” or “small intestine bacterial overgrowth” have now become somewhat commonplace. As it is estimated that there are more bacteria in our intestines than cells in our body, we should take note of how we care for these microscopic organisms.
Recent research has shown that the gut communicates with the brain through what’s known as the ‘gut-brain axis.’ Among its many functions, this axis plays a key role in regulating serotonin levels. Serotonin is a neurotransmitter that influences mood, sleep, and appetite, with 90% of it being produced by the gut. There is also research that shows the gut brain axis plays a role in certain GI complaints like irritable bowel syndrome (1). While we have not directly identified which of the gut bacteria are responsible for these alterations in mood and function, we do believe it is likely related to the homeostasis of numerous bacteria within our intestinal tract.
The microbiome is shaped by factors such as location, personal interactions, and dietary choices. Small dietary changes can lead to significant improvements in gut health. While many patients may ask for a quick fix or pill format of probiotics to help with their gut health, this may not be the best way. Many times, these pills are required to be refrigerated and have a fairly short shelf life. Many individuals take these pills, but because of the heat during transportation or time from production to consumption is too long, there are few (if any) healthy bacteria left in the pill. One of the easiest methods to improve the biodiversity of the gut microbiome is to eat foods with healthy bacteria and yeast.
One way to increase your intake of beneficial microorganisms is by eating SCOBYs (Symbiotic Cultures of Bacteria and Yeast). Popular examples of SCOBYs include sourdough starter, kombucha, sauerkraut, kimchi, and kefir. Sourdough and kombucha have gained popularity in recent years, sauerkraut and kimchi are well known in many cultures, yet kefir remains relatively unknown to many. Kefir offers numerous health benefits, including improved digestion, immune support, and enhanced mental clarity.
Kefir is a SCOBY traditionally used to ferment milk, producing a tart, yogurt-like drink. One of the best things about kefir is how easy it is to incorporate it into one’s diet. Whether enjoyed on its own, blended into a smoothie, or added to recipes, kefir is a versatile and simple way to support gut health. Kefir grains are easy to maintain, can be added to various foods, drinks, dressings, and dips, and are full of beneficial microbes that help balance the gut microbiome. Kefir can be purchased at most stores or, like sourdough starter, kept alive by feeding it regularly. A systematic review of kefir shows that regular consumption of kefir may help reduce dental caries, aid in Helicobacter pylori treatment, and has some potential benefits for chronic conditions like hypertension and hyperlipidemia (2). We could go on, but many probiotics have been found to have similar effects when consumed regularly.
A 2023 study published in Nutrients found that probiotic supplementation—such as the kind found in kefir—can improve depressive symptoms in some patients. Other research has confirmed that fermented foods can help reduce gut inflammation and promote a healthier mood (3). In general, there is no evidence for the frequency of ingestion of fermented foods. I typically recommend patients start with once a week and increase the frequency to include some form of probiotic once a day. Some groups even recommend it more often, especially if the patient is taking antibiotics.
Our role is to help promote healthy habits in our patients. Often, a small change can have profound impacts on a patient’s health and quality of life. Consider recommending probiotic rich foods to your patients with mood or gastrointestinal complaints. They may find that regular addition of probiotics to one’s diet can have significant impacts on their health. Speaking from personal experience, I can always tell when I have slacked off on my probiotic consumption.
References:
- Mayer EA, Nance K, Chen S. The Gut-Brain Axis. Annu Rev Med. 2022 Jan 27;73:439-453. doi: 10.1146/annurev-med-042320-014032. Epub 2021 Oct 20. PMID: 34669431.
- Kairey L, Leech B, El-Assaad F, Bugarcic A, Dawson D, Lauche R. The effects of kefir consumption on human health: a systematic review of randomized controlled trials. Nutr Rev. 2023 Feb 10;81(3):267-286. doi: 10.1093/nutrit/nuac054. PMID: 35913411.
- Ng QX, Lim YL, Yaow CYL, Ng WK, Thumboo J, Liew TM. Effect of Probiotic Supplementation on Gut Microbiota in Patients with Major Depressive Disorders: A Systematic Review. Nutrients. 2023 Mar 10;15(6):1351. doi: 10.3390/nu15061351. PMID: 36986088; PMCID: PMC10052013.