Microbial mucosal colonic shifts associated with the development of colorectal cancer reveal the presence of different bacterial and archaeal biomarkers

BACKGROUND

Epidemiological studies demonstrate a link between gastrointestinal cancers and environmental factors such as diet. It has been suggested that environmental cancer risk is determined by the interaction between diet and microbes. Thus, the purpose of this study was to examine the hypothesis that microbiota composition during colorectal cancer (CRC) progression might differ depending on the stage of the disease.

METHODS

A total of 28 age-matched and sex-matched subjects, seven with CRC adenocarcinoma, 11 with tubular adenomas and ten healthy subjects with intact colon, were included into the study. Microbiomes from mucosal and fecal samples were analyzed with 16S ribosomal RNA gene pyrosequencing, together with quantitative PCR of specific bacteria and archaea.

RESULTS

The principal coordinates analysis clearly separated healthy tissue samples from polyps and tumors, supporting the presence of specific bacterial consortia that are associated with affected sites and that can serve as potential biomarkers of CRC progression. A higher presence of Fusobacterium nucleatum and Enterobacteriaceae was found by qPCR in samples from CRC compared to healthy controls. We observed a correlation between CRC process development and levels of Methanobacteriales (R = 0.537, P = 0.007) and Methanobrevibacterium (R = 0.574, P = 0.03) in fecal samples.

CONCLUSION

Differences in microbial and archaeal composition between mucosal samples from healthy and disease tissues were observed in tubular adenoma and adenocarcinoma. In addition, microbiota from mucosal samples represented the underlying dysbiosis, whereas fecal samples seem not to be appropriate to detect shifts in microbial composition. CRC risk is influenced by microbial composition, showing differences according to disease progression step and tumor severity.

Transcription profiling reveals potential mechanisms of dysbiosis in the oral microbiome of rhesus macaques with chronic untreated SIV infection

A majority of individuals infected with human immunodeficiency virus (HIV) have inadequate access to antiretroviral therapy and ultimately develop debilitating oral infections that often correlate with disease progression. Due to the impracticalities of conducting host-microbe systems-based studies in HIV infected patients, we have evaluated the potential of simian immunodeficiency virus (SIV) infected rhesus macaques to serve as a non-human primate model for oral manifestations of HIV disease. We present the first description of the rhesus macaque oral microbiota and show that a mixture of human commensal bacteria and “macaque versions” of human commensals colonize the tongue dorsum and dental plaque. Our findings indicate that SIV infection results in chronic activation of antiviral and inflammatory responses in the tongue mucosa that may collectively lead to repression of epithelial development and impact the microbiome. In addition, we show that dysbiosis of the lingual microbiome in SIV infection is characterized by outgrowth of Gemella morbillorum that may result from impaired macrophage function. Finally, we provide evidence that the increased capacity of opportunistic pathogens (e.g. E. coli) to colonize the microbiome is associated with reduced production of antimicrobial peptides.

Femoral hernia: the dire consequences of a missed diagnosis

Femoral hernia has always presented more difficulty in diagnosis than other external abdominal hernias. The incidence of incarceration and strangulation is higher in our series than the published literature would suggest. A retrospective study was performed at our institution from February 1990 to June 1995. In that period, 22 patients were operated on for femoral hernia. There were 16 women and 6 men, average ages 51 and 48 years, respectively. The men weighed on average 209 lb, and the women, 154 lb. Three of our patients had elective repair of their hernias (16%); 19 were performed urgently or emergently (86%). Of the emergency repairs, 3 had strangulated small bowel requiring resection (16%), 1 had a strangulated vermiform appendix with abscess formation (5%), 3 had strangulated omentum requiring excision (16%), giving a total of 7 patients with strangulation and necrosis of the hernial contents (36%). The remainder had viable contents in the hernia sac. The time from the onset of symptoms to presentation at the hospital varied from 1 day to 3 years. The time from strangulation to presentation was between a few hours and 4 days. Surgery was performed on the day of admission (within 24 hours) on all but 2 of our patients. Procedures performed were McVay repair, 13; Bassini, 4; laparoscopic with Marlex mesh, 1 patient; drainage of a groin abscess in 2 patients with later repair; and on 2 patients the type of repair was not specified. One of the patients died. Postoperative wound infection occurred in 2 heavily contaminated patients, and 3 had pneumonia. Patients with no regular physician and no routine physical examinations are at higher risk for developing strangulation of femoral hernias. Emergency physicians and general practitioners are in the best position to diagnose these hernias early, when treatment can be elective.