Jun Zhao,1,2,* Xia Li,3,* Xin Wang,4 Xuefei Wang,4 Xin Hao,2 Zhigang Li,2 Lin Zhu1 

1Department of Integrated Traditional and Western Medicine, West China Hospital, Sichuan University, Chengdu, 610044, People’s Republic of China; 2School of Acupuncture-Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing, 100029, People’s Republic of China; 3Department of Physiology, Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, People’s Republic of China; 4Beijing Hospital of Traditional Chinese Medicine, Capital Medical University, Beijing, 100010, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Zhigang Li; Lin Zhu, Email lizhigang620@126.com; 13880262860@163.com

Background: To identify irritable bowel syndrome with diarrhea (IBS-D) combined with anxiety and/or depression through a psychological screening tool and to further explore the relationships between patients with comorbidities and gut microbiota.
Methods: The GAD-7, SAS, PHQ-9 and SDS were administered to evaluate anxiety and depression. Faeces were subsequently collected from 44 patients with emotional disorders (IBS-EDs), 22 patients without emotional disorders (IBS-nEDs) and 18 healthy controls (HCs) via 16S rRNA sequencing, depending on the participants’ wishes. The differences in gut microbiota among different groups were analysed. Spearman analysis was conducted at the genus level and was based on psychological assessment scores. Patients with IBS-D were recruited from December 2020 to November 2022.
Results: This study included 124 outpatients with IBS-D. According to the GAD-7 and SAS scores, 40.3% and 19.3% of the participants, respectively, had anxiety (P < 0.05). Similarly, a significantly greater percentage of participants had depression according to the PHQ-9 than according to the SDS (61.3% vs 33.1%) (P < 0.05). Overall, approximately 66.1% of the participants had emotional disorders (anxiety and/or depression) according to the GAD-7 and PHQ-9. Correlation analysis revealed that the abundances of Eubacterium_hallii_group, Monoglobus and Lachnoclostridium were closely related to the PHQ-9 scores and that the abundances of Subdoligranulum and Holdemanella were closely related to the GAD-7 scores.
Conclusion: In comparison to the SAS and SDS, both the GAD-7 and PHQ-9 identified a greater number of individuals with emotional disorders within the IBS-D population. Furthermore, our findings demonstrated that Lachnoclostridium is not only a biomarker for IBS-ED patients but also that its abundance changes are related to PHQ-9 scores, which may provide insights for further brain gut investigations.

Keywords: depression, anxiety, IBS-D, 16S rRNA