**5. Conclusions**

The current study only indicates a mild hyperhomocysteinemia-driven exacerbation of the AD-like phenotype, simulated in the *AppNL-G-F* knock-in mouse model. Dietary interventions consisting of B-vitamins and/or PUFAs as well as the FC-like diet as a complex micronutrient mixture were unable to modify cognitive performance in this mouse model for AD. Neither the B-vitamin deficient diet, resulting in elevated HCys and HCA levels, nor the potentially beneficial diets affected the amount of plaque deposition in the brain. In comparison with the age-matched C57BL/6J wild type control group, *AppNL-G-F* control mice displayed merely subtle behavioral deficits at the investigated age. Further investigations should clarify whether the *AppNL-G-F* genotype and the experimental diets have an impact in older animals.

**Author Contributions:** Conceptualization, N.d.B., U.T., M.J.P. and G.G.; Data curation, H.N. and O.A.; Formal analysis, H.N.; Funding acquisition, G.G.; Investigation, H.N., O.A., M.S. and D.S.; Methodology, N.d.B., M.C.J.H., M.S., R.G. and D.S.; Project administration, M.J.P. and G.G.; Resources, T.S. and T.C.S.; Software, H.N. and O.A.; Supervision, N.d.B. and U.T.; Validation, O.A., M.C.J.H., M.S. and R.G.; Visualization, H.N.; Writing–original draft, H.N.; Writing–review & editing, N.d.B., O.A., M.C.J.H., M.S., T.S., T.C.S., R.G., D.S., U.T., M.J.P. and G.G. All authors have given approval to the final version of the manuscript.

**Funding:** This research was funded by MEDICE Arzneimittel Pütter GmbH & Co. KG.

**Acknowledgments:** We wish to thank MEDICE Arzneimittel Pütter GmbH & Co. KG for funding this preclinical study. Furthermore, we thank RIKEN Center for Brain Science for providing the *AppNL-G-F* knock-in mice.

**Conflicts of Interest:** The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.
