Research is inconclusive surrounding bipolar disorder and gut health. However, consuming probiotics can help boost overall immune and digestive health, which may improve the well-being of a person with bipolar disorder.

Researchers have found that people with certain mental health conditions, such as bipolar disorder, have different gut bacteria compositions than those without these conditions.

This has led to speculations about whether consuming probiotics, which help promote overall gut health, can improve the mental wellness of people living with bipolar disorder.

This article discusses the connection between the gut and the brain, research surrounding probiotics and mental health, and whether probiotics can improve symptoms of bipolar disorder.

There are an estimated 50 trillion bacteria in the average gut. Other microorganisms also live in the gut but in fewer quantities, including roughly 140,000 viruses. These, along with certain fungi, live in the digestive tract, which includes the stomach, small intestine, and large intestine.

Besides digestion, the gut microbiome plays an important role in supporting a person’s immune system and brain health. Scientists now know that the gut links to the brain via millions of nerves and refer to it as the gut-brain-microbiota axis. This link facilitates the exchange of information between the two organs.

Specific gut bacteria species are responsible for producing chemical substances that the brain needs, called neurotransmitters. For example, one neurotransmitter — serotonin — is crucial to brain health, mood, and behavior. The gut is one of the organs that produce it.

Researchers found another important gut-brain connection when they discovered that individuals with varying psychological disorders — including bipolar disorder — have different gut bacteria species than those without psychological conditions.

Individuals with inadequate gut microbiomes are often prone to inflammatory digestive diseases such as irritable bowel syndrome (IBS). A 2016 systematic review and meta-analysis found that those with IBS were prone to mental health conditions, and those with IBS were twice as likely to have bipolar disorder as those without IBS.

Furthermore, the diversity of gut bacteria tends to be different in those with bipolar when compared with the composition of those without the condition. Specifically, there was an imbalance in the ratio of certain bacteria that usually live in the gut.

People with bipolar disorder have lower levels of Faecalibacterium, a healthy bacteria. Faecalibacterium is one of the most essential bacteria for maintaining gut health. It helps to reduce inflammation in the gut lining, making it more hospitable for other microorganisms, thus maintaining a balanced gut microbiome.

Medications that help treat bipolar disorder can modify the bacteria ratio in the gut.

There is no clear link between gut bacteria and mental health conditions such as bipolar disorder. However, some studies suggest there may be a correlation between an imbalance in gut bacteria and these conditions. It is important to note that everyone’s gut microbiome is different, and it is difficult to attribute bipolar disorder to any one factor since other health conditions often coexist.

Bipolar disorder is not the only condition tied to the gut microbiome. Schizophrenia, autism, and depression are current investigations concerning digestive tract health. All three conditions, along with bipolar disorder, have been found to produce significant alterations in gut microbiome composition compared with those without mental health disorders.

These alterations can cause digestive health conditions in addition to affecting mental wellness. For example, inflammatory bowel disease (IBD) often occurs along with depression, with more than 20% of people with IBD having depression symptoms and sleep disturbances.

A 2020 study found those with schizophrenia tend to develop IBD at a younger age. As with bipolar disorder, though researchers speculate there is a link between gut health and these mental health disorders, there is not yet enough research to clearly identify the relationship and use it to determine possible treatments.

Despite the lack of wide-scale research to prove any causal relationship, some speculate that improving the gut microbiome, in general, may benefit mental health conditions. A common approach to promote gut health is consuming probiotics, often called “good bacteria.”

A doctor may recommend probiotics when there is a loss of healthy gut bacteria, such as after a person has taken a course of antibiotics.

Probiotics come in different strains, and each has specific benefits for the gut, such as helping to replenish the microbiome and stimulating nerves to move food through the digestive system.

Probiotics can come from food and supplements. However, a recent investigative treatment used fecal microbiota transplantation, in which a doctor transfers bacteria from one healthy individual to another. The results were promising for resolving infections in the body, and researchers are investigating it as a treatment for mental health disorders.

Research from 2020 is mainly inconclusive as to whether probiotics benefit those with bipolar disorder. A 2018 study produced promising results, but the outcome needed to be more significant to conclude probiotics efficacy.

Nevertheless, there are advantages to taking probiotics. First, probiotics can help reduce gut inflammation, one of the most vital links to bipolar disorder. Additionally, they help to balance gut bacteria. For example, healthier gut bacteria can help:

Probiotics can take some time to work, often months. Possible side effects include bloating, brain fog, constipation, and abdominal discomfort. If a person wishes to add probiotics to their routine, they should discuss this with a doctor. While supplements are an option, some could make false claims, stating that they benefit consumers more than they actually do.

The bacteria types and counts are also factors to consider. Strain diversity is essential. The most researched bacteria tend to be Lactobacillus, Bifidobacterium, and Bacillus, which can be most helpful in numbers of at least 1 billion colony-forming units.

Certain foods are rich in probiotics. Yogurt, kefir, sauerkraut, tempeh, and kimchi are some of the most popular gut health-promoting foods. For a person to achieve gut microbiome robustness, it may be beneficial to diversify dietary intake to include nutritional sources with compounds other than probiotics. For example, foods that contain butyric acid, such as butter and hard cheese, can help support the breakdown of fiber in the gut, easing digestion.

Probiotics help reduce inflammation and support the body’s immune system by promoting gut microbiome health. Both inflammation and overstimulation of the immune system can contribute to mental health disorders, making probiotics a potential factor in lessening the severity of conditions such as bipolar disorder.

However, research is still inconclusive. Scientists have not established a direct correlation between specific gut health conditions and bipolar disorder.

On the other hand, if a person appropriately consumes probiotics under the guidance of a medical professional, it may produce various health benefits ranging from immune support to fewer bouts of indigestion.