Objective: Depression and anxiety are the most common psychological disorders with extensive pathophysiology overlap, genetic correlation, and comorbidities as well as high risk of recurrence and chronicity. Due to the side effects of medication and not achieving the expected result, the use of probiotics is considered as an adjunctive treatment option without serious side effects. Methods: This is a correlational study conducted in Spring 2020 on 279 people (76 males and 203 females) aged 20-40 years in Tehran, Iran who had at least a diploma and were selected by a convenience sampling method after declaring informed consent. For collecting data, the Beck Depression Inventory, the Beck Anxiety Inventory, and a researcher-made probiotic consumption questionnaire were used and completed online. Data were analyzed using Pearson correlation test and multivariable regression analysis in SPSS v. 26 software. Results: Out of 279 participants, 209 (74.9%) had moderate probiotic consumption, 3.6% had good consumption and the rest had poor consumption. Probiotic consumption had significant negative correlation with depression (r= -0.183, P= 0.002) and anxiety (r= -0.122, P= 0.041). Despite the significant predictive power of probiotics for explaining depression, it had no significant power to predict anxiety. The regression coefficient was obtained as R=0.233; squared regression coefficient was R2=0.054, and P-values for depression and anxiety were 0.016 and 0.430, respectively. Conclusion: The use of probiotics may have reduce depression and anxiety. To obtain more accurate results, clinical trials on the use of probiotics are recommended.