BackgroundThe upper half of the human small intestine, known as the jejunum, is the primary site for absorption of nutrient-derived carbohydrates, amino acids, small peptides, and vitamins. In contrast to the colon, which contains 1011–1012 colony forming units of bacteria per ml (CFU/ml), the normal jejunum generally ranges from 103 to 105 CFU per ml. Because invasive procedures are required to access the jejunum, much less is known about its bacterial microbiota. Bacteria inhabiting the jejunal lumen have been investigated by classical culture techniques, but not by culture-independent metagenomics.ResultsThe lumen of the upper jejunum was sampled during enteroscopy of 20 research subjects. Culture on aerobic and anaerobic media gave live bacterial counts ranging from 5.8 × 103 CFU/ml to 8.0 × 106 CFU/ml. DNA from the same samples was analyzed by 16S rRNA gene-specific quantitative PCR, yielding values from 1.5 × 105 to 3.1 × 107 bacterial genomes per ml. When calculated for each sample, estimated bacterial viability ranged from effectively 100% to a low of 0.3%. 16S rRNA metagenomic analysis of uncultured bacteria by Illumina MiSeq sequencing gave detailed microbial composition by phylum, genus and species. The genera Streptococcus, Prevotella, Veillonella and Fusobacterium, were especially abundant, as well as non-oral genera including Escherichia, Klebsiella, and Citrobacter. The jejunum was devoid of the genera Alistipes, Ruminococcus, Faecalibacterium, and other extreme anaerobes abundant in the colon. In patients with higher bacterial loads, there was no significant change in microbial species composition.ConclusionsThe jejunal lumen contains a distinctive bacterial population consisting primarily of facultative anaerobes and oxygen-tolerant obligate anaerobes similar to those found in the oral cavity. However, the frequent abundance of Enterobacteriaceae represents a major difference from oral microbiota. Although a few genera are shared with the colon, we found no evidence for retrograde movement of the most abundant colonic microbes to the jejunum. Some individuals had much higher bacterial loads, but this was not correlated with decreases in bacterial species diversity or other evidence of dysbiosis.Electronic supplementary materialThe online version of this article (doi:10.1186/s12866-017-1059-6) contains supplementary material, which is available to authorized users.

UC was more common among US Hispanics compared to NHW. Age at IBD diagnosis is similar for both Hispanics and NHW. For CD, disease behavior is similar, but Hispanics show a trend for less upper gastrointestinal involvement. A family history of IBD and smoking history were less common in Hispanics.

The glucose-based hydrogen and methane breath test is not sensitive to the overgrowth of jejunal bacteria. However, a positive breath test may indicate altered jejunal function and microbial dysbiosis.

IntroductionInvasive Aspergillus commonly involves the lungs, but can also affect other organs such as the skin, adrenal glands, central nervous system, liver, spleen and the gastrointestinal tract. Gastrointestinal aspergillosis is rare and is most often discovered in immunocompromised patients. There is only one other case report to our knowledge that describes the diagnosis being discovered on histopathological analysis of endoscopic biopsies of necrotic ulcers.Case presentationA 36-year-old Hispanic woman presented with septic shock secondary to extensive Fournier gangrene that required multiple surgical debridement of the perineal and retroperitoneal area. Her vital signs on admission were a temperature of 39.4°C and blood pressure of 85/56mmHg, pulse rate of 108/min and respiratory rate of 25. An examination of the perineum/genital area revealed bilateral gluteal and perilabial edema, erythema and focal areas of necrotic tissue with purulent discharge. Other surgeries included small bowel resections with ileoileal anastomosis that later developed an anastomotic leak that required and diverting end ileostomy. Eleven weeks after admission, our patient developed hematochezia from the colostomy associated with a decrease in hemoglobin and hematocrit to 6.4g/dL and 20.2% respectively. Colonoscopy through the ostomy revealed blood throughout the colon and a 3cm necrotic ulcer with an adherent clot in the transverse colon. Biopsies were taken from the edge of the ulcer. Histopathological analysis of the specimen with Grocott’s methenamine silver stain revealed septated hyphae with the 45-degree-angle branching that is morphologically consistent with Aspergillus species. Our patient was treated with intravenous voriconazole for 30 days with a prolonged hospitalization but no recurrent bleeding.ConclusionsGastrointestinal aspergillosis is an unusual presentation of invasive Aspergillus associated with a high mortality rate. Characteristic features of gastrointestinal aspergillosis include invasion of the mesenteric arteries, intravascular thrombosis and subsequent tissue ischemia. Clinical manifestations of invasive Aspergillus of the gastrointestinal tract can include fever, abdominal pain, ileus, peritonitis, bloody diarrhea or hematochezia. In an autopsy series of patients with invasive Aspergillus, 37 of 107 patients had Aspergillus involvement of the gastrointestinal system; the most common pathological findings included ulcers and abscesses. Although rare, invasive aspergillosis may present with gastrointestinal bleeding associated with necrotic ulcers on endoscopic examination.