The human gut microbiota is involved in host health and disease development. Therefore, lifestyle-related diseases such as hypertension (HT), hyperlipidemia (HL), and type 2 diabetes mellitus (T2D) may alter the composition of gut microbiota. Here, we investigated gut microbiota changes related to these diseases and their coexistence. This study involved 239 Japanese subjects, including healthy controls (HC). The fecal microbiota was analyzed through the isolation of bacterial genomic DNA obtained from fecal samples. Although there were no significant differences in the microbial structure between groups, there was a significant difference in the α-diversity between HC and the patients in whom two diseases coexisted. Moreover, Actinobacteria levels were significantly increased, whereas Bacteroidetes levels were significantly decreased in all disease groups. At the genus level, Bifidobacterium levels were significantly increased in the HL and T2D groups, as were those of Collinsella in all disease groups. In contrast, Alistipes levels were significantly lower in the HL group. Furthermore, metabolic enzyme families were significantly increased in all disease groups. Interestingly, the structure and function of the gut microbiota showed similar profiles in all the studied diseases. In conclusion, several changes in the structure of the gut microbiota are associated with T2D, HT, and HL in Japanese subjects.

Partially hydrolyzed guar gum (PHGG) is a water-soluble dietary fiber and is used in solid and liquid food to regulate gut function. The aim of this study was to investigate effects of PHGG on bowel movements (stool form and frequency), plasma bile acids, quality of life, and gut microbiota of healthy volunteers with a tendency toward diarrhea, i.e., irritable bowel syndrome diarrhea (IBS-D)-like symptoms. A randomized, double-blind, placebo-controlled, and parallel trial was performed on 44 healthy volunteers (22 males, 22 females, 41.9 ± 6.3 years old (average ± SD)) with minimum 7 bowel movements every week, wherein above 50% of their stool was between the Bristol stool scale (BSS) value of 5 and 6. Intake of the PHGG for 3 months significantly improved stool form, evaluated using BSS, and had no effects on stool frequency. BSS was significantly normalized in the group consuming the PHGG compared with the placebo. Comprehensive fecal microbiome analysis by the 16S rRNA-sequence method detected significant changes in the ratio of some bacteria, such as an increase of Bifidobacterium (p < 0.05) in the PHGG group. Our results suggest that intake of PHGG improves human stool form via regulating intestinal microbiota.

Background: Functional dyspepsia (FD) is associated with poor health-related quality of life. Recent evidence suggests that the main pathogenesis suspect is the gut mucosa-associated microbiota (MAM). However, little is known about the MAM in FD subjects. The aim of this study was to clarify the relationship between upper gastrointestinal symptoms in FD and the characteristics of the gastrointestinal MAM. Summary: Five mucosa samples from the upper gut (intraoral, mid-esophagus, gastric body, gastric antrum, and descending portion of the duodenum) were collected with a brush under endoscopic examination from FD and healthy control subjects. MAM profiles of each sample were analyzed by 16S-rRNA ­V3-V4 gene sequences. Questionnaire was used to assess gastrointestinal symptoms in FD. Between FD and healthy control subjects, although the comparison of MAM α-diversity showed no significant differences, the structure of MAM (β-diversity) was clearly different. Only the phylum Firmicutes was increased in FD compared to healthy control subjects in all sites of the upper gut. At the genus level, Streptococcus was significantly increased in all sites in the upper gut in FD. The relative abundance of Streptococcus was positively correlated with upper gastrointestinal symptoms in each upper gut group. Furthermore, the relative abundance of OTU 90 was positively correlated with upper gastrointestinal symptoms in all sites in the upper gut in FD. Key Messages: Streptococcus is a bacterium strongly correlated with upper gastrointestinal symptoms in FD.

Background. BTB and CNC homolog 1 (Bach1) is a transcriptional repressor of heme oxygenase-1 (HO-1), which plays an important role in the protection of cells a

Partially hydrolysed guar gum (PHGG), a water-soluble dietary fibre produced by the controlled partial enzymatic hydrolysis of guar gum beans, has various physiological roles. This study aimed to elucidate the beneficial effects of PHGG on colonic mucosal damage in a murine 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis model. Acute colitis was induced in male C57BL/6 mice with TNBS after 2 weeks of pre-feeding with PHGG (5 %). The colonic mucosal inflammation was evaluated using macroscopic damage scores, and neutrophil infiltration was assessed by measuring tissue-associated myeloperoxidase (MPO) activity in the colonic mucosa. TNF-αexpression in the colonic mucosa was measured by ELISA and real-time PCR. Moreover, the intestinal microbiota and production of SCFA were assessed by real-time PCR and HPLC, respectively. Colonic damage due to TNBS administration was significantly ameliorated by PHGG treatment. Furthermore, PHGG significantly inhibited increases in MPO activity and TNF-αprotein and mRNA expression in the colonic mucosa in TNBS-induced colitis. On analysis of intestinal microbiota, we found that the concentration of theClostridium coccoidesgroup (Clostridiumcluster XIVa), theClostridium leptumsubgroup (Clostridiumcluster IV) and theBacteroides fragilisgroup had significantly increased in PHGG-fed mice. On analysis of SCFA, we found that the caecal content of acetic acid, propionic acid and butyric acid had significantly increased in PHGG-fed mice. Together, these results suggest that chronic ingestion of PHGG prevents the development of TNBS-induced colitis in mice by modulating the intestinal microbiota and SCFA, which may be significant in the development of therapeutics for inflammatory bowel disease.