## 5 Conclusions  
In conclusion, MALDI-TOF MS is a tool for rapid, accurate, and cost-effective identification of cultured bacteria and fungi in clinical microbiology. We agree with literature data suggesting that there is no single causative bacterial organism responsible in CRC. However, we believe that there is sufficient evidence suggesting that the reduction of protective bacteria or, vice versa, an increase of noxious strains, induced by diet in association with lifestyle and age, could influence the development of proliferative lesions. Apart from SCFAs produced by gut bacteria, the control of pathogenic species in the intestine could be determined by natural dietary compounds (i.e., polyphenols, essential oils, etc.) and a lot of immune regulators and mediators, partly tested in daily practice [48; 49; 50].  
Future studies will enable to better understand both pro-carcinogenic and anti-carcinogenic mechanisms and will shed lights on the rational manipulation of the human microbiota and on the use of prebiotics, probiotics, or dietary modifications to improve health conditions.  
The role of the diet in influencing the composition of the human microbiota is certainly not to be neglected. It is worldwide accepted that diet can influence the composition of the human microbiota, and that the supplementation with specific dietary resistant starch (RS) may lead to changes in fecal microbiota profiles associated with improved bowel health [51].  
We know for sure that bacterial species might be greatly influenced by the presence of different nutrients, fibers etc. in diet and this aspect need to be resolved together with the concept of high variability and poor number of subjects included in the study.  
Having this in mind, the manipulation of oncogenic, high risk gut microbiota may became an effective tool for cancer prevention, as well as treatment possibly based on fecal transplantation and lifestyle modifications.  
However, this study was aimed to establish how different is the microbiota in subjects with or without intestinal polyps, regardless of dietary habits. So, for this study we just asked to the participants if they have had always the same dietary habits.  
An evaluation of dietary habits would have made sense if we wanted to establish the type of foods that promote the development of certain bacterial species. But this aspect was beyond the scope of our study. In addition, although BMI was comparable between the two groups, no information is provided concerning the dietary habits in the weeks before assessment of intestinal microbiota.  
**Ethical Statement:** The protocol study was approved by the Ethics Committee of the University of Bari, Protocol Record Policlinic Hospital, Bari, ClinicalTrials.gov Identifier: NCT03417258. Written informed consent was obtained from all study subjects.  
**Author Contributions:** Conceptualization, L.P., M.B. and L.S.; Methodology, L.P., M.B. and L.S.; validation, L.P., M.B. and A.M.; investigation, L.P., M.B., A.M. and L.S.; resources, A.D.L.; data curation, M.B., M.T.V., and L.S.; writing--original draft preparation, L.P., M.B. and L.D.; writing--review and editing, L.P., M.B. and L.S.; visualization, M.B. and M.T.; supervision, A.D.L.; project administration, L.P., M.B. and L.S; funding acquisition, M.B. and A.D.  
**Funding:** This paper has been partly funded by the Italian Ministry of University and Research--PON-BIOMIS 2018 (Project: _Costutzione della Biobanca del Microbiota intestinale e salivare unano: dalla disbiosi alla simbiosis_).  
**Conflicts of Interest:** The authors declare no conflict of interest.