Mild Depression

The goal of this clinical trial is to learn if daily single-strain probiotic supplementation (Lactobacillus plantarum) works to improve cognitive function and depressive symptoms in Egyptian women aged 50-64 years with mild depression. It will also learn about its effects on systemic inflammation and autonomic nervous system function via the gut-brain axis The main questions it aims to answer are: Does a 12-week probiotic supplementation improve cognitive function (measured by MoCA-B) compared to a placebo? Does it reduce the severity of depressive symptoms (measured by BDI-II)? Does it reduce systemic inflammation (measured by hs-CRP levels in the blood)? Does it enhance autonomic nervous system function (measured by Heart Rate Variability - HRV via a smartphone app)? Researchers will compare the probiotic capsule (Lactobacillus plantarum, 10 billion CFU) to a placebo (a look-alike capsule containing starch) to see if the probiotic works better than placebo. Participants will: Take one probiotic or placebo capsule orally every morning with breakfast for 12 weeks. Visit the Family Medicine outpatient clinic at baseline and at 12 weeks for cognitive and psychological tests, HRV measurements, and blood tests. Receive weekly follow-up messages on WhatsApp to monitor adherence and report any dietary changes or potential side effects.

The primary goal is to investigate to what extent changes in glutamate and glutathione modulation and functional integration between brain networks associated with emotion and attention regulation are associated with treatment response in mildly depressed youth.