An Investigation into the Effectiveness of Probiotics Present in Kefir in Managing Stress and Anxiety in College Students. A Randomised Controlled Trial with Assessment of Nutritional Status.

Background: With anxiety and stress becoming increasingly prevalent, the need for practical interventions warrants attention. Nutritional psychiatry has considered probiotics, omega-3, vitamin D and fibre in managing mental health via the gut-brain axis. Introduction: This paper aimed to determine the effectiveness of kefir in managing anxiety, stress and gastrointestinal (GI) health. It also examined the role of omega-3, vitamin D and fibre in relation to the same variables and GI health’s influence on anxiety and stress. Methods: 16 participants were assigned to an intervention (kefir) or control (rice milk) group to consume 250ml of their allocated drinks for 14 consecutive days. Anxiety, stress, GI health and dietary intake were measured pre- and post-intervention. Results: Anxiety significantly reduced in both kefir (Mean difference = 2.5, p = 0.033) and control groups (Mean difference = 4.6, p = 0.005), with no significant difference between groups (p = 0.197). There were non-significant changes in stress or GI health. A moderate correlation was observed between GI health and anxiety (r = 0.042, p = 0.017). Nutrient intake had no significant associations with anxiety, stress or GI health. Conclusion: Kefir may reduce anxiety, though placebo effects should be considered. Future research should include longer trials, larger samples and biomarker use.