Altered Tryptophan Metabolism on the Kynurenine Pathway in Depressive Patients with Small Intestinal Bacterial Overgrowth
The causes of depression are diverse and are still not fully understood. Recently, an increasing role is attributed to nutritional and inflammatory factors. The aim of this study was to evaluate selected metabolites of the tryptophan kynurenine pathway in depressive patients with small intestinal ba...
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MDPI AG
2022-08-01
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| Series: | Nutrients |
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| Online Access: | https://www.mdpi.com/2072-6643/14/15/3217 |
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| author | Cezary Chojnacki Paulina Konrad Aleksandra Błońska Marta Medrek-Socha Karolina Przybylowska-Sygut Jan Chojnacki Tomasz Poplawski |
| author_facet | Cezary Chojnacki Paulina Konrad Aleksandra Błońska Marta Medrek-Socha Karolina Przybylowska-Sygut Jan Chojnacki Tomasz Poplawski |
| author_sort | Cezary Chojnacki |
| collection | DOAJ |
| description | The causes of depression are diverse and are still not fully understood. Recently, an increasing role is attributed to nutritional and inflammatory factors. The aim of this study was to evaluate selected metabolites of the tryptophan kynurenine pathway in depressive patients with small intestinal bacterial overgrowth (SIBO). The study involved 40 healthy people (controls) and 40 patients with predominant small intestinal bacterial overgrowth (SIBO-D). The lactulose hydrogen breath test (LHBT) was performed to diagnose SIBO. The severity of symptoms was assessed using the Gastrointestinal Symptom Rating Scale (GSRS–IBS) and the Hamilton Depression Rating Scale (HAM-D). The concentration of tryptophan (TRP), kynurenine (KYN), kynurenic acid (KYNA), and quinolinic acid (QA) in urine was determined using an LC–MS/MS method, before and after cyclic treatment with an antibiotic drug, rifaximin, for three months. The number of intraepithelial lymphocytes (IELs) in the duodenum and small intestinal mucosa, fecal calprotectin (FC) and serum level of <i>C</i>-reactive protein (CRP) were also determined. In patients with SIBO, a higher level of KYN and QA were found as compared to the control group. These two groups also differed in KYN/TRP (higher in SIBO) and KYNA/KYN ratios (lower in SIBO). A positive correlation was found between HAM-D and the number of IELs and the level of FC. Treatment with rifaximin improves the kynurenic pathway, as well as abdominal and mental complaints. Therefore, small intestinal bacterial overgrowth can be a cause of abdominal symptoms, but also mental disorders. |
| first_indexed | 2024-03-09T12:17:58Z |
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| issn | 2072-6643 |
| language | English |
| last_indexed | 2024-03-09T12:17:58Z |
| publishDate | 2022-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Nutrients |
| spelling | doaj.art-770bf7e140aa476482bfa6274c51dd552023-11-30T22:44:45ZengMDPI AGNutrients2072-66432022-08-011415321710.3390/nu14153217Altered Tryptophan Metabolism on the Kynurenine Pathway in Depressive Patients with Small Intestinal Bacterial OvergrowthCezary Chojnacki0Paulina Konrad1Aleksandra Błońska2Marta Medrek-Socha3Karolina Przybylowska-Sygut4Jan Chojnacki5Tomasz Poplawski6Department of Clinical Nutrition and Gastroenterological Diagnostics, Medical University of Lodz, 90-647 Lodz, PolandDepartment of Clinical Nutrition and Gastroenterological Diagnostics, Medical University of Lodz, 90-647 Lodz, PolandDepartment of Clinical Nutrition and Gastroenterological Diagnostics, Medical University of Lodz, 90-647 Lodz, PolandDepartment of Clinical Nutrition and Gastroenterological Diagnostics, Medical University of Lodz, 90-647 Lodz, PolandDepartment of Pharmaceutical Microbiology and Biochemistry, Medical University of Lodz, 90-136 Lodz, PolandDepartment of Clinical Nutrition and Gastroenterological Diagnostics, Medical University of Lodz, 90-647 Lodz, PolandDepartment of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, 90-236 Lodz, PolandThe causes of depression are diverse and are still not fully understood. Recently, an increasing role is attributed to nutritional and inflammatory factors. The aim of this study was to evaluate selected metabolites of the tryptophan kynurenine pathway in depressive patients with small intestinal bacterial overgrowth (SIBO). The study involved 40 healthy people (controls) and 40 patients with predominant small intestinal bacterial overgrowth (SIBO-D). The lactulose hydrogen breath test (LHBT) was performed to diagnose SIBO. The severity of symptoms was assessed using the Gastrointestinal Symptom Rating Scale (GSRS–IBS) and the Hamilton Depression Rating Scale (HAM-D). The concentration of tryptophan (TRP), kynurenine (KYN), kynurenic acid (KYNA), and quinolinic acid (QA) in urine was determined using an LC–MS/MS method, before and after cyclic treatment with an antibiotic drug, rifaximin, for three months. The number of intraepithelial lymphocytes (IELs) in the duodenum and small intestinal mucosa, fecal calprotectin (FC) and serum level of <i>C</i>-reactive protein (CRP) were also determined. In patients with SIBO, a higher level of KYN and QA were found as compared to the control group. These two groups also differed in KYN/TRP (higher in SIBO) and KYNA/KYN ratios (lower in SIBO). A positive correlation was found between HAM-D and the number of IELs and the level of FC. Treatment with rifaximin improves the kynurenic pathway, as well as abdominal and mental complaints. Therefore, small intestinal bacterial overgrowth can be a cause of abdominal symptoms, but also mental disorders.https://www.mdpi.com/2072-6643/14/15/3217l-tryptophankynurenic pathwaysmall intestinal bacterial overgrowthmood disorders |
| spellingShingle | Cezary Chojnacki Paulina Konrad Aleksandra Błońska Marta Medrek-Socha Karolina Przybylowska-Sygut Jan Chojnacki Tomasz Poplawski Altered Tryptophan Metabolism on the Kynurenine Pathway in Depressive Patients with Small Intestinal Bacterial Overgrowth Nutrients l-tryptophan kynurenic pathway small intestinal bacterial overgrowth mood disorders |
| title | Altered Tryptophan Metabolism on the Kynurenine Pathway in Depressive Patients with Small Intestinal Bacterial Overgrowth |
| title_full | Altered Tryptophan Metabolism on the Kynurenine Pathway in Depressive Patients with Small Intestinal Bacterial Overgrowth |
| title_fullStr | Altered Tryptophan Metabolism on the Kynurenine Pathway in Depressive Patients with Small Intestinal Bacterial Overgrowth |
| title_full_unstemmed | Altered Tryptophan Metabolism on the Kynurenine Pathway in Depressive Patients with Small Intestinal Bacterial Overgrowth |
| title_short | Altered Tryptophan Metabolism on the Kynurenine Pathway in Depressive Patients with Small Intestinal Bacterial Overgrowth |
| title_sort | altered tryptophan metabolism on the kynurenine pathway in depressive patients with small intestinal bacterial overgrowth |
| topic | l-tryptophan kynurenic pathway small intestinal bacterial overgrowth mood disorders |
| url | https://www.mdpi.com/2072-6643/14/15/3217 |
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