*4.4. S4H FCDB's Future Perspective*

The S4H FCDB consists of interlinked tables that make a complete nutritional information system. S4H FCDB not only allows accurate calculations, but also provides the user with information on different aspects integrated in the personalized nutrition system. The purpose of the S4H FCDB was for it to be used in epidemiological studies, in particular precision nutritional studies. This S4H FCDB will be connected to an app that will be used during the nutritional intervention of the project. The study aims to generate personalized nutritional recommendations to different populations, more specifically adults and children [56]. The app derived from the S4H Project will be an automated diet evaluator and generator used from smartphones. A set of more than 10,000 recipes from all countries is expected to be available. All recipes will be implemented in a mobile app for future nutritional intervention. An example is depicted in Figure 4. Other similar apps have a smaller number of foods and were developed from a smaller number of food data sources [82].

**Figure 4.** Shows the relationship between MySQL tables and how the recipe is generated in the APP.

The S4H FCDB will be able to connect to other tools. One of the milestones of personalized nutrition is to understand the health level of the gut microbiota of a given patient. The S4H FCDB generated data will also be completed with the use of AGREDA [99], an extended reconstruction of diet metabolism by the human gut microbiota. The S4H FCDB will also introduce commercial products, incorporating allergens and different scores as used in Open Food Facts [16]. These products and fast foods from the different countries of the project will make S4H FCDB more comprehensive and representative [38]. The data will also be updated periodically to avoid obsolescence [5], which will be possible thanks to traceability.

In the future it is expected that the S4H FCDB will be extended by implementing toxic substances, such as food processing contaminants, as few FCDBs contain these components [15,88,100–102]. Due to the importance of climate change in nutrition, sustainability parameters and different markers of climate change would be an added value to be included [13]. Finally, in order to identify food-disease associations [55], food biomarkers could be introduced by linking them to FOBI (Food-Biomarker Ontology) [36], or extending

the compounds related to https://foodb.ca (accessed on 27 October 2021) or other big data sources [24,98].

#### **5. Conclusions**

S4H FCDB was built through a huge scientific work to collect and harmonize all the nutritional data. S4H FCDB is one of the most comprehensive FCDB with more than ten FCDBs used, which is one of its main unique characteristics. This food database is comparable to that used in other relevant studies, such as EPIC. A large number of harmonized foods (over 2000) and more than 800 nutrients and bioactive compounds (such as polyphenols) have been included, the inclusion of such a large number of bioactive compounds being another unique strength of the paper. S4H FCDB attempts to mitigate the usual limitations, such as variability in food composition, errors, and missing values in the national FCT/FCDB databases. Trained personnel following the guidelines of official agencies were able to homogenize the information. This made it possible to unify foods, their nutrients and bioactive compounds among the FCT/FCDBs using the median value as the reference value. The values obtained were less extreme and made it possible to complete the national FCT/FCDB. The S4H FCDB has many perspectives, not only the implementation in nutritional studies through an application. But it is also capable of being part of other tools and has the versatility to be continuously enhanced with much more information. Thus, S4H FCDB becomes a solid and indispensable tool to approach the age of personalized nutrition.

**Supplementary Materials:** The following are available online at https://www.mdpi.com/article/10 .3390/nu13124206/s1, Table S1: INFOODS Tagnames used in S4H FCDB, Code S2: Code used in the S4H FCDB unification stage. Figure S3: Figure with the absence or presence of different compounds and nutrients in the FCDB. All compounds are included and expressed with FAO/INFOODS names.

**Author Contributions:** Conceptualization, V.G.-V. and J.Á.R.-H.; Methodology, D.H.-N., B.N.-P. and S.P.d.l.C.; Software, B.O.-V. and V.G.-V.; Validation, D.H.-N. and S.P.-B.; Formal analysis, D.H.-N., S.P.-B., B.N.-P. and B.O.-V.; Investigation, A.F. and S.P.d.l.C.; Resources, S.P.-B., F.L. and V.G.-V.; Data curation, D.H.-N. and B.O.-V.; Writing—Original draft preparation, D.H.-N. and S.P.-B.; Writing— Review and editing, A.F., F.L., K.N.P., S.P.-B. and J.Á.R.-H.; Supervision, V.G.-V. and J.Á.R.-H.; Funding acquisition, J.Á.R.-H. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by the European Research Commission (Research Executive Agency) under the research project Stance4Health (Grant Contract No. 816303) to José Á. Rufián-Henares. This work was supported by the "Plan propio de Investigación y Transferencia" of the University of Granada under the programs "Intensificación de la Investigación, modalidad B", granted to José Á. Rufián-Henares.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** The S4H FCDB is not freely available at the present moment, since it will be used along the research project. Those researchers aiming at using the S4H FCDB should request a license to José A. Rufián-Henares, who will transfer the request to the relevant S4H committee.

**Acknowledgments:** This work will be a part of the doctoral thesis of Daniel Hinojosa-Nogueira conducted within the context of the 'Program of Nutrition and Food Sciences' at the University of Granada.

**Conflicts of Interest:** The authors declare no conflict of interest.
