Specific prebiotics modulate gut microbiota and immune activation in HAART-naive HIV-infected adults: results of the “COPA” pilot randomized trial

Intestinal mucosal immune system is an early target for human immunodeficiency virus type 1 (HIV-1) infection, resulting in CD4+ T-cell depletion, deterioration of gut lining, and fecal microbiota composition. We evaluated the effects of a prebiotic oligosaccharide mixture in highly active antiretroviral therapy (HAART)-naive HIV-1-infected adults. In a pilot double-blind, randomized, placebo-controlled study, 57 HAART-naive HIV-1-infected patients received a unique oligosaccharide mixture (15 or 30 g short chain galactooligosaccharides/long chain fructooligosaccharides/pectin hydrolysate-derived acidic oligosaccharides (scGOS/lcFOS/pAOS) daily) or a placebo for 12 weeks. Microbiota composition improved significantly with increased bifidobacteria, decreased Clostridium coccoides/Eubacterium rectale cluster, and decreased pathogenic Clostridium lituseburense/Clostridium histolyticum group levels upon prebiotic supplementation. In addition, a reduction of soluble CD14 (sCD14), activated CD4+/CD25+ T cells, and significantly increased natural killer (NK) cell activity when compared with control group were seen in the treatment group. The results of this pilot trial highly significantly show that dietary supplementation with a prebiotic oligosaccharide mixture results in improvement of the gut microbiota composition, reduction of sCD14, CD4+ T-cell activation (CD25), and improved NK cell activity in HAART-naive HIV-infected individuals

The Human Nasal Microbiota and Staphylococcus aureus Carriage

BACKGROUND: Colonization of humans with Staphylococcus aureus is a critical prerequisite of subsequent clinical infection of the skin, blood, lung, heart and other deep tissues. S. aureus persistently or intermittently colonizes the nares of approximately 50% of healthy adults, whereas approximately 50% of the general population is rarely or never colonized by this pathogen. Because microbial consortia within the nasal cavity may be an important determinant of S. aureus colonization we determined the composition and dynamics of the nasal microbiota and correlated specific microorganisms with S. aureus colonization. METHODOLOGY/PRINCIPAL FINDINGS: Nasal specimens were collected longitudinally from five healthy adults and a cross-section of hospitalized patients (26 S. aureus carriers and 16 non-carriers). Culture-independent analysis of 16S rRNA sequences revealed that the nasal microbiota of healthy subjects consists primarily of members of the phylum Actinobacteria (e.g., Propionibacterium spp. and Corynebacterium spp.), with proportionally less representation of other phyla, including Firmicutes (e.g., Staphylococcus spp.) and Proteobacteria (e.g. Enterobacter spp). In contrast, inpatient nasal microbiotas were enriched in S. aureus or Staphylococcus epidermidis and diminished in several actinobacterial groups, most notably Propionibacterium acnes. Moreover, within the inpatient population S. aureus colonization was negatively correlated with the abundances of several microbial groups, including S. epidermidis (p = 0.004). CONCLUSIONS/SIGNIFICANCE: The nares environment is colonized by a temporally stable microbiota that is distinct from other regions of the integument. Negative association between S. aureus, S. epidermidis, and other groups suggests microbial competition during colonization of the nares, a finding that could be exploited to limit S. aureus colonization