There’s Even More Evidence That Anxiety and Gut Health Are Related

Your brain and gut are inextricably connected, so it's no surprise that things like anxiety and stress can affect your gut health and vice versa. This is why stressful situations can cause your stomach to churn and pre-existing conditions, like irritable bowel syndrome, can make you feel anxious. But new research has taken this a step further, discovering that the state of your mental health is more specifically associated with the state of your gut microbiome—aka the balance of good and bad bacteria in your gut.

A narrative review recently published in the journal Nutrients analyzed several studies which suggest that people with anxiety disorders have less microbial (bacterial) diversity in their guts.¹ More specifically, the review found that people with increased anxiety symptoms had less beneficial bacteria in their systems, such as Lactobacillus, Bifidobacterium, and other short-chain fatty acids (substances released by the gut after fermenting dietary fiber), and an overgrowth of pro-inflammatory bacteria like Escherichia-Shigella, which may contribute to anxiety symptoms.

While more research is needed to determine why this connection exists, medical experts have pointed to probiotic supplementation as a potential means for correcting this bacterial imbalance and possibly managing anxiety. Previous research has also come to this conclusion, including a 2019 systematic review in the journal General Psychiatry, which analyzed over 1,000 people and the state of their gut and mental health.²

“Overall, 11 studies showed a positive effect on anxiety symptoms by regulating intestinal microbiota, which indicated 52 percent of the 21 studies were effective, and there were five studies that used probiotic supplements as interventions and six used non-probiotic interventions,” the General Psychiatry review authors wrote. Probiotics can help, but so can eating a diet rich in fermented foods, such as sauerkraut, yogurt, miso, and tempeh.

Both the Nutrients and General Psychiatry reviews provide clear links between mental and gastrointestinal health, but it's still unclear as to why this is. Older studies done in mice have found that gut bacteria may alter certain parts of the brain that regulate anxiety, such as the amygdala (i.e., the brain's center for emotional processing) and the prefrontal cortex (i.e., the part of the brain that regulates social fear responses), but we don't know if the same is true for humans.³ Though it does point to the possibility that certain gut bacteria affect parts of the mind that handle emotions.

Lastly, it's important to note that probiotics should not be considered a cure-all for treating both gut and mental health issues. While the introduction of good bacteria in the gut is beneficial, and certain foods can impact the state of your mental well-being, we don't have enough evidence to show that it can cure any specific gut health or mental health conditions. In this instance, it is best to see your healthcare provider to see what form of treatment is best for you.

Beyond gut health and diet, there are plenty of other factors that contribute to the development of anxiety symptoms, including lack of sleep, life circumstances, and other mental health issues like depression. So if you are experiencing anxiety that is interfering with your ability to live your life, it's best to reach out to a licensed mental health professional—to help you understand the root of what's going on.

Bottom line: the science is becoming more clear that gut health, your gut microbiome, and good bacteria (probiotics) are connected to your brain in some way. But more research is needed to fully understand how, and how best to support both areas of your health.