Equol is a metabolite of isoflavone daidzein and has an affinity to estrogen receptors. Although equol is produced by intestinal bacteria, the association between the status of equol production and the gut microbiota has not been fully investigated. The aim of this study was to compare the intestinal bacteria responsible for equol production in gut microbiota between equol producer and non-producer subjects regarding the intake of daidzein. A total of 1044 adult subjects who participated in a health survey in Hirosaki city were examined. The concentration of equol in urine was measured by high-performance liquid chromatography. The relative abundances of 8 bacterial species responsible for equol production in the gut microbiota was assessed using 16S rRNA amplification. There were 458 subjects identified as equol producers. The proportion of equol production status and the intake of daidzein increased with age. Daily intake of daidzein was larger in equol-producer. The intestinal bacteria, which convert daidzein to equol were present in both equol producers and non-producers. However, the relative abundance and the prevalence of Asaccharobacter celatus and Slackia isoflavoniconvertens were significantly higher in equol producers than those in equol non-producers. The intestinal bacteria that convert daidzein to equol are present in not only the equol producers but also in the non-producers. The daidzein intake is associated with the equol production status through an increase of A. celatus and S. isoflavoniconvertens in the gut microbiota.

The pathogenesis and refractory nature of inflammatory bowel disease (IBD) are related to multiple factors, including genetic factors, environmental factors, and abnormalities in gut microbial diversity, which lead to decreased levels of short-chain fatty acids (SCFAs). Among SCFAs, butyrate plays an important role in mucosal barrier maintenance, serves as an energy source in intestinal epithelial cells (IECs), and exhibits anti-inflammatory effects; therefore, it is a particularly important factor in gut homeostasis. Changes in gut microbiota and butyrate levels affect the outcomes of drug therapy for IBD. Butyrate is mainly absorbed in the large intestine and is transported by monocarboxylate transporter 1 (MCT1) and sodium-coupled monocarboxylate transporter 1 (SMCT1). During gut inflammation, butyrate utilization and uptake are impaired in IECs. Dysbiosis and low abundance of butyrate affect fecal microbiota transplantation and anticancer immunotherapy. Although butyrate administration has been reported as a treatment for IBD, its effects remain controversial. In this review, we discuss butyrate absorption and metabolism in patients with IBD and their relationship with drug therapy.

Objective. To evaluate the clinical and structural efficacy of tocilizumab (TCZ) during its long-term administration in patients with rheumatoid arthritis (RA). Methods. In total, 693 patients with RA who started TCZ therapy were followed for 3 years. Clinical efficacy was evaluated by DAS28-ESR and Boolean remission rates in 544 patients. Joint damage was assessed by calculating the modified total Sharp score (mTSS) in 50 patients. Results. When the reason for discontinuation was limited to inadequate response or adverse events, the 1-, 2-, and 3-year continuation rates were 84.0%, 76.8%, and 72.2%, respectively. The mean DAS28-ESR was initially 5.1 and decreased to 2.5 at 6 months and to 2.2 at 36 months. The Boolean remission rate was initially 0.9% and increased to 21.7% at 6 months and to 32.2% at 36 months. The structural remission rates (ΔmTSS/year ≤0.5) were 68.8%, 78.6%, and 88.9% within the first, second, and third years, respectively. The structural remission rate at 3 years (ΔmTSS ≤1.5) was 66.0%, and earlier achievement of swollen joint count (SJC) of 1 or less resulted in better outcomes. Conclusions. TCZ was highly efficacious, and bone destruction was strongly prevented. SJC was an easy-to-use indicator of joint destruction.

Background/Aims: Thiopurines are key drugs for inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn’s disease (CD). Recently, NUDT15 polymorphism (R139C, c.415C > T) has been shown to be associated with thiopurineinduced adverse events in Asian populations. In patients with the C/T genotype, low-dose thiopurine treatment is recommended, but its long-term efficacy and tolerability remain unclear. This study aimed to uncover the long-term efficacy and appropriate dosage of thiopurine for IBD patients with the C/T genotype.Methods: A total of 210 patients with IBD (103 UC and 107 CD) determined to have NUDT15 R139C variants were enrolled. Clinical data were retrospectively reviewed from medical records.Results: Of 46 patients (21.9%) with the C/T genotype, 30 patients (65.2%) were treated with thiopurines. Three of whom (10.0%) discontinued thiopurine treatment due to adverse events and 27 of whom continued. The median maintenance dosage of 6-mercaptopurine was 0.25 mg/kg/day (range, 0.19–0.36 mg/kg/day), and 6-thioguanine nucleotides level was 230 (104–298) pmol/8 × 108 red blood cells. Cumulative thiopurine continuation rates for 120 months for patients with the C/C and C/T genotypes were not significantly different (P= 0.895). Cumulative non-relapse rates in the patients with UC treated with thiopurine monotherapy and surgery-free rates in CD patients treated with combination therapy (thiopurines and anti-tumor necrosis factor-α agents) for maintenance remission were not significantly different at 60 months (C/C vs. C/T, P= 0.339 and P= 0.422, respectively).Conclusions: Low-dose thiopurine treatment is an effective and acceptable treatment for patients with C/T genotype.

The Japanese diet is a healthy dietary pattern, and the oral or gut microbiota have been identified as the main factors underlying the beneficial effects of the Japanese diet. However, epidemiological studies on Japanese dietary patterns calculated from daily eating habits in the general population yielded inconsistent findings. This study aimed to determine the association between the 12-component modified Japanese Diet Index (mJDI12) and the oral and gut microbiota in the general population of a rural area in Japan. After propensity-score matching, 396 participants (198 each in the low and high mJDI12 groups) were picked out. One year after the follow up survey, we reclassified the subjects and compared the low and high mJDI12 groups again. Participants with a high mJDI12 had a higher relative abundance of butyric acid-producing bacteria in their gut microbiota. Moreover, the significantly higher dietary fiber intake in the high mJDI12 group suggested that the high intake of dietary fiber contributed to an increase in butyric acid-producing bacteria in the gut. In contrast, in individuals with a high mJDI12, only Allpprevotella was decreased in the oral microbiota. Thus, the Japanese dietary pattern can have beneficial effects by improving the oral and gut microbiota.

We describe herein a case of severe relapsed pyoderma gangrenosum (PG) concomitantly with severe pouchitis treated by tacrolimus. A 25-year-old woman had undergone proctocolectomy with construction of ileo-anal pouch surgery for refractory ulcerative colitis (UC). She first developed PG with refractory pouchitis, and infliximab (IFX) was administered to induce remission due to resistance to glucocorticoid therapy. After achieving remission, IFX was stopped. Five years later, severe skin ulcers concomitantly with severe pouchitis recurred and treatment with 30 mg oral prednisolone (PSL) combined with topical tacrolimus showed partial improvement. When PSL was tapered to 15 mg, the skin ulcers and diarrhea aggravated. Endoscopy revealed multiple ulcers in the ileal pouch. Treatment with oral tacrolimus was initiated for severe pouchitis and refractory PG. Forty days later, all skin ulcers became scars and multiple ulcers in the ileal pouch were also improved. Our case suggests that oral tacrolimus treatment could be a valuable treatment option for UC patients with refractory PG and pouchitis.