Discovery of Bacteroides uniformis F18-22 as a Safe and Novel Probiotic Bacterium for the Treatment of Ulcerative Colitis from the Healthy Human Colon.

Previous studies have demonstrated that the intestinal abundance of Bacteroides uniformis is significantly higher in healthy controls than that in patients with ulcerative colitis (UC). However, what effect B. uniformis has on the development of UC has not been characterized. Here, we show for the first time that B. uniformis F18-22, an alginate-fermenting bacterium isolated from the healthy human colon, protects against dextran-sulfate-sodium (DSS)-induced UC in mice. Specifically, oral intake of B. uniformis F18-22 alleviated colon contraction, improved intestinal bleeding and attenuated mucosal damage in diseased mice. Additionally, B. uniformis F18-22 improved gut dysbiosis in UC mice by increasing the abundance of anti-inflammatory acetate-producing bacterium Eubacterium siraeum and decreasing the amount of pro-inflammatory pathogenetic bacteria Escherichia-Shigella spp. Moreover, B. uniformis F18-22 was well-tolerated in mice and showed no oral toxicity after repeated daily administration for 28 consecutive days. Taken together, our study illustrates that B. uniformis F18-22 is a safe and novel probiotic bacterium for the treatment of UC from the healthy human colon.

The fecal microbiota transplantation response differs between patients with severe and moderate irritable bowel symptoms.

OBJECTIVES: Fecal microbiota transplantation (FMT) is a promising intervention for patients with irritable bowel syndrome (IBS). The present study aimed to identify any differences in FMT response between patients with severe and moderate IBS symptoms. MATERIALS AND METHOD: The study included the 164 patients who participated in our previous study, of which 96 (58.5%) and 68 (41.5%) had severe (S-IBS-S) and moderate (Mo-IBS-S) IBS, respectively. The patients were randomly divided into a placebo group (own feces) and 30-g and 60-g (donor feces) FMT groups. Patients completed three questionnaires that assessed their symptoms and quality of life at baseline and at 2 weeks, 1 month, and 3 months after FMT, and provided fecal samples before and 1 month after FMT. The fecal bacteria were analyzed using the 16S rRNA gene in PCR DNA amplification covering the V3-V9 variable genes. RESULTS: Response rates of the placebo group did not differ between S-IBS-S and Mo-IBS-S patients at 2 weeks, 1 month and 3 months after FMT. The response rates in the active treatment group were higher in S-IBS-S patients than in Mo-IBS-S patients at each observation time. FMT reduced abdominal symptoms and fatigue and improved the quality of life in patients with both severe and moderate IBS. Patients with S-IBS-S had higher levels of Eubacterium siraeum, and lower levels of Eubacterium rectale than Mo-IBS-S, after FMT. CONCLUSION: Patients with S-IBS-S have a higher response rate to FMT and a marked improvement in fatigue and in quality of life compared with those with Mo-IBS-S. The clinical trial registration number is NCT03822299 and is available at www.clinicaltrials.gov.

Diet, obesity, and the gut microbiome as determinants modulating metabolic outcomes in a non-human primate model.

BACKGROUND: The objective of this study was to increase understanding of the complex interactions between diet, obesity, and the gut microbiome of adult female non-human primates (NHPs). Subjects consumed either a Western (n=15) or Mediterranean (n=14) diet designed to represent human dietary patterns for 31 months. Body composition was determined using CT, fecal samples were collected, and shotgun metagenomic sequencing was performed. Gut microbiome results were grouped by diet and adiposity. RESULTS: Diet was the main contributor to gut microbiome bacterial diversity. Adiposity within each diet was associated with subtle shifts in the proportional abundance of several taxa. Mediterranean diet-fed NHPs with lower body fat had a greater proportion of Lactobacillus animalis than their higher body fat counterparts. Higher body fat Western diet-fed NHPs had more Ruminococcus champaneliensis and less Bacteroides uniformis than their low body fat counterparts. Western diet-fed NHPs had significantly higher levels of Prevotella copri than Mediterranean diet NHPs. Western diet-fed subjects were stratified by P. copri abundance (P. copriHIGH versus P. copriLOW), which was not associated with adiposity. Overall, Western diet-fed animals in the P. copriHIGH group showed greater proportional abundance of B. ovatus, B. faecis, P. stercorea, P. brevis, and Faecalibacterium prausnitzii than those in the Western P. copriLOW group. Western diet P. copriLOW subjects had a greater proportion of Eubacterium siraeum. E. siraeum negatively correlated with P. copri proportional abundance regardless of dietary consumption. In the Western diet group, Shannon diversity was significantly higher in P. copriLOW when compared to P. copriHIGH subjects. Furthermore, gut E. siraeum abundance positively correlated with HDL plasma cholesterol indicating that those in the P. copriLOW population may represent a more metabolically healthy population. Untargeted metabolomics on urine and plasma from Western diet-fed P. copriHIGH and P. copriLOW subjects suggest early kidney dysfunction in Western diet-fed P. copriHIGH subjects. CONCLUSIONS: In summary, the data indicate diet to be the major influencer of gut bacterial diversity. However, diet and adiposity must be considered together when analyzing changes in abundance of specific bacterial taxa. Interestingly, P. copri appears to mediate metabolic dysfunction in Western diet-fed NHPs. Video abstract.