A bacterium found in fermented foods and yogurt may be used to develop new treatments for depression and anxiety.
About 39 trillion microorganisms, including bacteria and fungi, live inside the human digestive system. Collectively called the microbiota, these microorganisms are critical to maintaining the immune system function.
Studies have suggested that the microbiota imbalance may also increase the risk of mental health disorders, such as anxiety and depression.
Earlier research by scientists at the University of Virginia School of Medicine found that the bacterium called Lactobacillus helped to improve mood disorders and was lost following psychological stress. Using the bacteria, the researchers could even reverse depression in lab mice.
In their new study published in the journal Brain, Behavior, and Immunity, the researchers used a collection of bacteria known as Altered Schaedler Flora, including two strains of Lactobacillus and six other bacterial strains.
The researchers created mice with and without Lactobacillus, circumventing the need for antibiotics. While it is a standard study method to use antibiotics to disrupt the microbiota and colonize it with the bacteria of interest, the medication can cause off-target effects.
The study found that the Lactobacilli bacteria maintain the levels of an immune mediator called interferon gamma that regulates the body’s response to stress and helps prevent depression.
The findings may pave the way to new treatments for depression and other mental health conditions, the authors say. For instance, the therapy could include specially formulated probiotic supplements that will optimize their levels of Lactobacillus.
How to improve gut health
Large clinical trials with humans are needed before Lactobacillus probiotics can be used to prevent or treat depression.
However, maintaining the microbiota balance is crucial to prevent gastrointestinal conditions such as inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS), as well as obesity, type 2 diabetes, and atopy.
What microbiota a person has depends on their family genes, environment, and medication use. The food they eat is another major factor influencing gut health.
The British Health Foundation recommends eating 30 plant foods weekly, such as fruits and vegetables, whole grains, legumes, nuts, and seeds.
Constipation, diarrhea, or stomach cramps can be signs of the microbiome imbalance, but many people with unhealthy gut won’t show any symptoms.
While probiotic supplements are commonly used to alleviate these symptoms and improve the gut microbiota, some foods are natural sources of probiotics:
- Yogurt and kefir
- Sauerkraut (fermented cabbage)
- Tempeh (a fermented soybean product)
- Kimchi (a spicy dish mostly made from fermented cabbage)
- Kombucha (fermented black or green tea)
The study shows promise in treating mental health disorders with Lactobacillus. However, probiotics cannot replace medication and psychotherapy. If you experience symptoms of anxiety or depression, discuss them with your healthcare provider.