Inflammatory bowel disease (IBD), which mainly includes ulcerative colitis (UC) and Crohn's disease (CD), is a group of chronic bowel diseases that are characterized by abdominal pain, diarrhea, and bloody stools. IBD is strongly associated with depression, and its patients have a higher incidence of depression than the general population. Depression also adversely affects the quality of life and disease prognosis of patients with IBD. The tryptophan-kynurenine metabolic pathway degrades more than 90% of tryptophan (TRP) throughout the body, with indoleamine 2,3-dioxygenase (IDO), the key metabolic enzyme, being activated in the inflammatory environment. A series of metabolites of the pathway are neurologically active, among which kynerunic acid (KYNA) and quinolinic acid (QUIN) are molecules of great interest in recent studies on the mechanisms of inflammation-induced depression. In this review, the relationship between depression in IBD and the tryptophan-kynurenine metabolic pathway is overviewed in the light of recent publications.

The efficacy and mechanisms of acupuncture for Crohn's disease (CD) are not well understood. We investigated its effects on symptoms, intestinal microbiota, and circulating inflammatory markers in CD patients. This 48-week, randomized, sham controlled, parallel-group clinical trial was performed at a tertiary outpatient clinic in China. From April 2015 to November 2019, 66 patients (mean age 40·4, 62·1% were male, all were Han Chinese) with mild to moderate active CD and unresponsive to drug treatment were enrolled and randomly assigned equally to an acupuncture group or a sham group. The treatment group received 3 sessions of acupuncture plus moxibustion per week for 12 weeks and a follow-up of 36 weeks. Clinicaltrials.gov: NCT02559037. At week 12, the clinical remission rate (the primary outcome) and clinical response rate of acupuncture group were significantly higher than that of sham group, with a difference of 42·4% (95% CI: 20·1%-64·0%) and 45·5% (95% CI: 24·0%-66·9%), respectively, both of which maintained at week 48. The acupuncture group had significantly lower CD activity index and C-reactive protein level at week 12, which maintained at 36-week follow-up. The CD endoscopic index of severity, histopathological score, and recurrence rate at week 48 were significantly lower in acupuncture group. The number of operational taxonomic unit of intestinal microbiota and relative abundance of Faecalibacterium prausnitzii and Roseburia faecis were increased. Plasma diamine oxidase, lipopolysaccharide, and Th1/Th17 related cytokines were decreased in 12-week after acupuncture. Acupuncture was effective in inducing and maintaining remission in patients with active CD, which was associated with increased abundance of intestinal anti-inflammatory bacteria, enhanced intestinal barrier, and regulation of circulating Th1/Th17-related cytokines. National Key Basic Research Program of China (2015CB554500 and 2009CB522900), Shanghai Rising-Star Program (19QA1408100).

Moxibustion therapy is a traditional Chinese medicine external treatment method, which involves crushing dried herb Artemisia argyi H. Lév. & Vanio and rolling it into a long cigarette-like strip, igniting it and using its warmth to stimulate specific acupuncture points for a certain period of time. It is often used in Asia to treat various diseases, especially abdominal pain. Clinical reports suggest that acupuncture and moxibustion are the effective treatment for Irritable Bowel Syndrome with Diarrhea (IBS-D). However, there is no placebo-controlled study to prove its safety and efficacy. To evaluate the effects of mild moxibustion (MM) for the treatment of irritable bowel syndrome with diarrhea (IBS-D) through comparisons with those of placebo moxibustion. This was a single-site, randomized controlled trial was conducted at Shanghai Research Institute of Acupuncture and Meridian in China and enrolled 76 participants who met the Rome IV diagnostic criteria for IBS-D between May 2017 and December 2019. 76 participants were randomized to either mild moxibustion (MM) or placebo moxibustion group (PM) in a 1:1 ratio. 18 sessions of MM or PM were implemented over the course of 6 weeks (3 times per week). The primary outcome was adequate relief after 6 weeks of treatment. Of 76 patients with IBS-D who were randomized (38 in the MM group and 38 in the PM group) were included in the intention-to-treat (ITT) analysis set. After treatment at week 6, the response rate was significantly higher in the MM group than the PM group (81.58% vs. 36.84%) with an estimated difference of 44.74 (95% CI, 23.46 to 66.02, P < 0.001). No participant reported severe adverse effects. The findings suggest that mild moxibustion may be more effective than placebo moxibustion for the treatment of IBS-D, with effects lasting up to 12 weeks. ChiCTR, ChiCTR2100046852. Registered 29 May 2021 - Retrospectively registered, URL: http://www.chictr.org.cn/showproj.aspx?proj=127000.

Inflammatory bowel disease (IBD) refers to chronic inflammatory disorders of the gut. Ulcerative colitis (UC) and Crohn’s disease (CD) are two subtypes of IBD. Evidence suggests that the intestinal microbiota plays a role in the pathogenesis of IBD, so probiotics have garnered a lot of interest as a potential treatment or prevention for IBD. However, clinical evidence of the efficacy of probiotics is still debatable. We performed a literature review. An advanced search considered clinical studies on probiotic for IBD from inception to 2023 in PubMed, Embase, Cochrane Library, and Web of Science. In the treatment of UC with probiotics, only Escherichia coli Nissle 1917 for maintenance treatment of UC in remission, and Bifidobacterium and VSL#3 for induction of remission in patients with mild to moderately active UC have shown strong evidence. Currently, there are no definitive conclusions regarding the effectiveness of probiotics in CD. The mechanism of probiotic treatment for IBD may be related to reducing oxidative stress, repairing the intestinal barrier, regulating intestinal flora balance, and modulating intestinal immune response. Differences in the benefits of probiotics between CD and UC may be attributable to the different lesion extent and immune-mediated pathophysiology. More robust randomized clinical trials are required to validate the efficacy and safety of diverse probiotic strains in IBD.

Moxibustion is one of the most commonly used therapies in acupuncture practice, and is demonstrated to be beneficial for patients with diarrhea from irritable bowel syndrome (D-IBS). But its mechanism remains unclear. Because visceral hypersensitivity in IBS patients has been documented by evaluation of perceived stimulations through functional magnetic resonance imaging (fMRI) studies, we focused on observing brain imaging changes in D-IBS patients during rectal balloon distention before and after moxibustion in order to reveal its possible central mechanism and further evaluate its effect. This clinical trial is registered under the number: ChiCTR-TRC-10000887. Eighty D-IBS patients were randomly divided into a moxibustion and sham moxibustion group (control group) for a 4-week treatment. Fifteen patients in moxibustion group and thirteen patients in control group completed two fMRI scans during a 50 and 100 ml rectal balloon distention before and after treatment. Rectal pain were obtained with a scan test. Birmingham IBS Symptom Scale and IBS Quality of Life (QOL) Scale were used to evaluate therapeutic effect. After treatment, the decrease in Birmingham IBS Symptom Scale and IBS QOL Scale scores in moxibustion group was significantly greater than that of control group (P < 0.01). The defecation urge threshold and the pain perception threshold of moxibustion group was also significantly higher after treatment than that of control group (P < 0.01). The decrease in pain score during the 100 ml rectal balloon distention in moxibustion group was significantly greater than that of control group (P < 0.05). There was no definite activated center during the 50 ml rectal distention in either group before treatment. After treatment, the prefrontal cortex (PFC) was affected in moxibustion group, while the PFC and the anterior cingulated cortex (ACC) were affected in control group. During the 100 ml distention before treatment in both groups, the PFC and ACC were activated. After treatment, they disappeared in moxibustion group but remained in control group. Moxibustion can improve symptoms and quality of life in D-IBS patients. It can also decrease rectal sensitivity. The activation of PFC and ACC during a 100 ml rectal distention disappeared after moxibustion treatment.

Aim. To compare whether there is different effect between electroacupuncture (EA) and moxibustion (Mox) on visceral hypersensitivity (their analgesic effects) in constipation‐predominant irritable bowel syndrome (C‐IBS). Methods. EA at 1 mA and 3 mA and Mox at 43°C and 46°C were applied to the Shangjuxu (ST37, bilateral) acupoint in rats with C‐IBS and normal rats. An abdominal withdrawal reflex (AWR) score was used to assess visceral hypersensitivity. Toluidine blue staining was used to assess mast cell (MC) activity in colon of rats. Immunochemistry was used to measure 5‐HT and 5‐HT4 receptor expression in the colon. Results. AWR scores in all EA (1 mA and 3 mA) and Mox (43°C and 46°C) treatment groups after colorectal distention (CRD) stimulation pressure of 20, 40, 60, and 80 mmHg were significantly lower than those of the model (MC) group (P all < 0.01). The MC counts and degranulation rates in the colon of all EA and Mox treatment groups and the MC group were significantly higher than those of the NC group (P all < 0.01). MC degranulation rates in the colon of all EA and Mox treatment groups were lower than those of the MC group (P all < 0.05). 5‐HT expression in colon of all EA and Mox treatment groups was significantly lower than that of the MC group (P all < 0.01), and 5‐HT4R expression in colon of both EA groups was significantly higher than that of the MC group (P both < 0.01). Conclusion. EA and Mox treatments may both ameliorate visceral hypersensitivity at different degree in rats with C‐IBS, and EA treatment was better than Mox.