**5. Conclusions**

In conclusion, the present findings indicate that the microbiota in patients with the schizophrenia episode is highly individualized, although it can be clustered into di fferent taxonomical (Type 1, with a predominance of *Prevotella*, and Type 2 with a higher abundance of *Bacteroides*, *Blautia,* and *Clostridium*) and functional groups; the microbiota does not change during six weeks of treatment with OLZ and is not associated with the weight gain that occurs in women treated with OLZ, as well as the treatment effectiveness. This study provides some insights into the metabolic effects of psychotropic drugs on gu<sup>t</sup> microbiota in SZ patients. Further long-term and placebo-controlled studies are needed to clarify the effect of OLZ on gu<sup>t</sup> microbiota.

**Supplementary Materials:** The following are available online at http://www.mdpi.com/2077-0383/8/10/1605/s1.

**Author Contributions:** Conceptualization, J.P.-W., A.B.-K. and J.S.; data curation, J.P.-W., M.K., A.B.-K., P.L., M.W. and I.Ł.; formal analysis, J.P.-W., M.K., P.L., K.S.-Z., W.M., B.M., J.K.-M., I.Ł. and J.S.; investigation, J.P.-W., M.K., ˙ A.B.-K., P.L., M.W., K.S.-Z., W.M., J.K.-M., I.Ł. and J.S.; methodology, J.S.; software, M.K.; supervision, J.P.-W. and ˙ J.S.; visualization, M.K.; writing—original draft, J.P.-W., M.K. and I.Ł.; writing—review and editing, J.P.-W., M.K., A.B.-K., M.W., K.S.-Z., W.M., B.M., T.S., I.Ł. and J.S. ˙

**Funding:** The study was funded within the framework of the project Fundusz Stymulacji Nauki (grant number: FSN-312-05/15) provided by Pomeranian Medical University at Szczecin (Poland) and National Science Centre (UMO-2018/31/B/NZ5/00527). The funding sources had no role in concept design, selection of articles, the decision to publish, or the preparation of the manuscript.

**Acknowledgments:** We would like to thank Editage (www.editage.com) for English language editing.

**Conflicts of Interest:** I.Ł. and W.M. are cofounders and shareholders at Sanprobi company. However, the content of this study was not constrained by this fact. Other authors declare no conflicts of interest.
