Observational Study
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Sep 28, 2019; 25(36): 5543-5558
Published online Sep 28, 2019. doi: 10.3748/wjg.v25.i36.5543
Evaluation and comparison of short chain fatty acids composition in gut diseases
Elena Niccolai, Simone Baldi, Federica Ricci, Edda Russo, Giulia Nannini, Marta Menicatti, Giovanni Poli, Antonio Taddei, Gianluca Bartolucci, Antonino Salvatore Calabrò, Francesco Claudio Stingo, Amedeo Amedei
Elena Niccolai, Simone Baldi, Edda Russo, Giulia Nannini, Antonio Taddei, Amedeo Amedei, Department of Experimental and Clinical Medicine, University of Florence, Florence 50134, Italy
Federica Ricci, Antonino Salvatore Calabrò, Department of Biomedical, Experimental and Clinical Sciences “Mario Serio” University of Florence, Florence 50134, Italy
Marta Menicatti, Gianluca Bartolucci, Department of Neurosciences, Psychology, Drug Research and Child Health Section of Pharmaceutical and Nutraceutical Sciences University of Florence, Florence 50134, Italy
Giovanni Poli, Francesco Claudio Stingo, Department of Statistics, Computer Science, Applications “G.Parenti”, Florence 50134, Italy
Amedeo Amedei, Department of Biomedicine, Azienda Ospedaliera Universitaria Careggi, Florence 50134, Italy
Author contributions: Niccolai E and Amedei A designed the study and interpreted results; Baldi S and Menicatti M performed research; Calabrò AS and Taddei A contributed to provide patients’ clinical informations; Ricci F, Nannini G and Russo E collected biological samples; Baldi S, Poli G, Niccolai E and Stingo FC analyzed data; Baldi S; Bartolucci G and Amedei A coordinated the research; Niccolai E and Baldi S wrote the paper; Bartolucci G, Stingo FC and Amedei A revised the manuscript.
Supported by Italian Society for Celiac Disease and Foundation for Celicac Disease, No. 007_FC_2016; Regione Toscana (The Programma Attuativo Regionale Toscana funded by FAS), No. MICpROBIMM.
Institutional review board statement: The study was reviewed and approved by the Comitato Etico Regionale per la Sperimentazione Clinica della Regione Toscana, Sezione AREA VASTA CENTRO Institutional Review Board (CE: 11166_spe and CE: 10443_oss).
Informed consent statement: All study participants or their legal guardian provided informed written consent about personal and medical data collection prior to study enrolment.
Conflict-of-interest statement: All the authors have no conflict of interest related to the manuscript.
Open-Access: This article is an open-access article which was selected byan in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Amedeo Amedei, BSc, Associate Professor, Department of Experimental and Clinical Medicine, University of Florence, Largo Brambilla 3, Florence 50134, Italy. aamedei@unifi.it
Telephone: +39-55-2758330 Fax: +39-55-4271495
Received: July 3, 2019
Peer-review started: July 3, 2019
First decision: August 2, 2019
Revised: September 2, 2019
Accepted: September 9, 2019
Article in press: September 9, 2019
Published online: September 28, 2019
Abstract
BACKGROUND

An altered (dysbiosis) and unhealthy status of the gut microbiota is usually responsible for a reduction of short chain fatty acids (SCFAs) concentration. SCFAs obtained from the carbohydrate fermentation processes are crucial in maintaining gut homeostasis and their determination in stool samples could provide a faster, reliable and cheaper method to highlight the presence of an intestinal dysbiosis and a biomarker for various gut diseases. We hypothesize that different intestinal diseases, such as celiac disease (CD), adenomatous polyposis (AP) and colorectal cancer (CRC) could display a particular fecal SCFAs’ signature.

AIM

To compare the fecal SCFAs’ profiles of CD, AP, CRC patients and healthy controls, using the same analytical method.

METHODS

In this cross-sectional study, we defined and compared the SCFAs’ concentration in fecal samples of 9 AP, 16 CD, 19 CRC patients and 16 healthy controls (HC). The SCFAs’ analysis were performed using a gas-chromatography coupled with mass spectrometry method. Data analysis was carried out using Wilcoxon rank-sum test to assess pairwise differences of SCFAs’ profiles, partial least squares-discriminate analysis (PLS-DA) to determine the status membership based on distinct SCFAs’ profiles, and Dirichlet regression to determine factors influencing concentration levels of SCFAs.

RESULTS

We have not observed any difference in the SCFAs’ amount and composition between CD and healthy control. On the contrary, the total amount of SCFAs was significantly lower in CRC patients compared to HC (P = 0.044) and CD (P = 0.005). Moreover, the SCFAs’ percentage composition was different in CRC and AP compared to HC. In detail, HC displayed higher percentage of acetic acid (P value = 1.3 × 10-6) and a lower amount of butyric (P value = 0.02192), isobutyric (P value = 7.4 × 10-5), isovaleric (P value = 0.00012) and valeric (P value = 0.00014) acids compared to CRC patients. AP showed a lower abundance of acetic acid (P value = 0.00062) and higher percentages of propionic (P value = 0.00433) and isovaleric (P value = 0.00433) acids compared to HC. Moreover, AP showed higher levels of propionic acid (P value = 0.03251) and a lower level of isobutyric acid (P value = 0.00427) in comparison to CRC. The PLS-DA model demonstrated a significant separation of CRC and AP groups from HC, although some degree of overlap was observed between CRC and AP.

CONCLUSION

Analysis of fecal SCFAs shows the potential to provide a non-invasive means of diagnosis to detect patients with CRC and AP, while CD patients cannot be discriminated from healthy subjects.

Keywords: Short chain fatty acids, Microbiota, Colorectal cancer, Adenoma, Celiac disease

Core tip: An altered gut microbiota is usually responsible for a reduction of short chain fatty acids (SCFAs) concentration. In this study, we analyse through gas-chromatography coupled with mass spectrometry the fecal SCFAs’ concentration in patients with various gut diseases [celiac disease (CD), adenomatous polyposis (AP) and colorectal cancer (CRC)]. Altought the small sample size of study does not allow us to reach definitive conclusions, our findings suggest the existence of a fecal SCFAs fingerprint in patients with CRC amd AP distinguishable from healthy controls. On the contrary, no differences between celiac patients and healthy controls was observed.