Psychological and physical health are intricately interrelated and important to the overall wellbeing of people. For example, mental health issues such as depression and anxiety increase the risk of many physical health problems, particularly long-lasting conditions such as diabetes, heart disease, and stroke. Similarly, the presence of chronic conditions can raise the risk of mental illnesses. Maintaining both aspects of health is critical, but while physical health issues are often readily manifest, mental health issues can be more difficult to detect and treat.
Researchers at the University of Virginia School of Medicine in the United States have now discovered that the bacterium Lactobacillus a common probiotic in fermented foods such as yogurt, and found abundantly among the microbiota in the digestive system, helps the body manage stress, thereby potentially reducing the onset of other mental health conditions such as depression and anxiety.
Previous studies have suggested that the bacterium Lactobacillus could reverse depression in mice. To understand why this happens, the researchers used the Altered Schaedler Flora (ASF) — a community of eight bacterial species including two strains of Lactobacillus and six other bacterial strains. The ASF was selected for their dominance and persistence in the normal microflora of mice, and for their ability to be isolated and grown in laboratory settings.
Germ-free mice were then colonized with ASF to study their gastrointestinal (GI) tract. The transfer of gut bacteria from stressed mice to germ-free mice was shown to lead to depression and anxiety-related behaviors. Mice without Lactobacillus, in particular, were shown to exhibit elevated stress responses and lower levels of an immune factor called interferon-gamma, which is involved in regulating stress response.
The results provide an innovative framework to understand the roles of the bacterial gut microbiome and the immune system in mood disorders. The study could also foster research into the development of new methods to treat and prevent mental health conditions. For example, in the future, people who are at risk of depression could take a probiotic supplement that contains Lactobacillus.
The study also provides further insights into the complex connections between gut health and mental wellbeing, which is increasingly becoming an area of interest in the field of nutrition. Health experts say the discovery that Lactobacillus, commonly found in fermented foods and yogurt, is linked to stress management and potential prevention of depression and anxiety, opens up exciting possibilities for holistic approaches to mental health.
The role of Lactobacillus in supporting mental health can be attributed to its impact on the gut-brain axis. Microbiota have been shown to influence and alter brain signaling, and stimulation, including to the gut. This bidirectional communication between the gut and the central nervous system suggests that ‘we are what we eat’.
Elaborating on their new discovery, the researchers said that an abundant presence of Lactobacillus in the gut appears to modulate the to and fro communication between gut and brain, influencing the production of neurotransmitters like serotonin and gamma-aminobutyric acid (GABA), which play key roles in mood regulation. Moreover, Lactobacillus apparently reduces inflammation in the gut which could indirectly contribute to improved mental health.
The researchers warned that it would be imprudent to suggest that simply getting more Lactobacillus into your diet could be a catch-all prevention tactic for mental health problems. Eating a healthier diet can certainly improve your mental health and impact how you respond to stress, but Lactobacillus is not a substitute for treatment. Rather, incorporating dietary considerations, including Lactobacillus-rich foods should be considered as a complementary strategy to a regular treatment aimed at managing stress, depression, and anxiety.
A holistic, complementary approach aligns with the emerging understanding that mental and physical health are interconnected, and emphasizes the importance of a well-balanced diet for overall well-being. Our mental health can be impacted by everything from experiencing childhood trauma or social disadvantage to genetics, age, lifestyle, and much more.
Diet is just one aspect of mental health management and that other lifestyle factors, including regular physical activity, adequate sleep, and stress management techniques also play crucial roles in improving mental health and overall wellbeing.
Nutritionists suggest that along with Lactobacillus-rich fermented foods there are other foods that are found beneficial in bringing about stress relief and improving mental health. For instance, a diet rich in omega-3 fatty acids, found in many fatty fish, flaxseeds, and walnuts, has been associated with reduced depressive symptoms. Other foods such as antioxidant-rich fruits and vegetables and whole grains, as well as leafy greens, nuts, and seeds loaded with magnesium can contribute to a diverse and nourishing diet that can positively impact mood and stress levels.