Maternal Vertical Microbial Transmission During Skin-to-Skin Care.

BACKGROUND: Skin-to-skin (STS) care may contribute to mother-to-infant vertical microbial transmission by enriching the preterm infant's microbiome. PURPOSE: The purpose of this observational study was to define the impact of increased STS care duration on vertical microbial transmission and consequently modulate oral and intestinal microbial balance. METHODS: Postpartum women and their preterm infants, 31 to 34 weeks' gestation (n = 25), were recruited for this study. Using 16S rRNA sequencing, we compared α- and ß-diversity with the Shannon and Chao indexes and nonmetric multidimensional scaling, respectively, and relative abundance of microbial communities, which refers to the percentage of specific organisms in a community, from mother's chest skin, preterm infant's oral cavity, and preterm infant's stool samples. Effects of STS care on vertical transmission were determined by comparing oral and stool microbial population of preterm infants who received low exposure (<40 minutes) with that of preterm infants who received high exposure (>60 minutes). RESULTS: Microbial composition, diversity, and relative abundance were different across the 3 sites. Oral microbial richness was less and stool richness was greater among the preterm infants in the high STS care group. Oral and intestinal microbial diversity and composition were different between the groups, with the relative abundance of Gemella and Aggregatibacter genera and Lachnospiraceae family significantly greater in the stool of the high STS care group. IMPLICATIONS FOR PRACTICE: Results suggest that STS care may be an effective method to enhance microbial communities among preterm infants.

Chronic opioid use modulates human enteric microbiota and intestinal barrier integrity.

Over the past three decades the United States has experienced a devastating opioid epidemic. One of the many debilitating side effects of chronic opioid use is opioid-induced bowel dysfunction. We investigated the impact of methadone maintenance treatment (MMT) on the gut microbiome, the gut bacterial metabolite profile, and intestinal barrier integrity. An imbalance in key bacterial communities required for production of short-chain fatty acids (SCFAs), mucus degradation, and maintenance of barrier integrity was identified. Consistent with dysbiosis, levels of fecal SCFAs were reduced in MMT. We demonstrated that metabolites synthesized by Akkermansia muciniphila modulate intestinal barrier integrity in vitro by strengthening the pore pathway and regulating tight junction protein expression. This study provides essential information about the therapeutic potential of A. muciniphila and warrants development of new clinical strategies that aim to normalize the gut microbiome in individuals affected by chronic opioid use.

Toll-like receptor distribution in colonic epithelium and lamina propria is disrupted in HIV viremic, immune success, and failure.

DESIGN: Since intestinal immunity and the microbiome are disrupted in HIV disease, we studied the abundance of innate immune sensors, Toll-like receptors (TLRs), in the mucosa of participants with viremia, prior to antiretroviral therapy (ART), immune success (>500 CD4 T cells/µl after 2 years of ART; suppressed viremia), and immune failure (<350 CD4 T cells/µl after 2 years of ART; suppressed viremia). We hypothesized that disruption of intestinal TLR abundance and location provides a mechanism behind persistent inflammation. METHODS: Immunofluorescence for TLR3, TLR4, and TLR9 on paraffin embedded biopsies from uninfected, viremic, immune success, and immune failure colons was imaged by deconvolution microscopy and quantified with MetaMorph software. Plasma levels of C-reactive protein, IL-6, and intestinal fatty-acid binding protein (I-FABP) were correlated with TLR expression. RESULTS: Viremic participants have significantly higher levels of TLR3 and TLR9 on surface epithelium and in crypts when compared with uninfected controls. TLR3 is further elevated in immune failure and immune success. TLR9 abundance remains elevated in immune failure and is normalized in immune success. TLR9 expression in the crypt and lamina propria positively associates with C-reactive protein and IL-6 and negatively with I-FABP. TLR4 is significantly lower on surface epithelium and higher in crypts in viremic. Its expression in the lamina propria positively correlates with IL-6 and negatively correlates with I-FABP. CONCLUSION: Mucosal TLR imbalance and deregulation, and the resulting mucosal TLR desensitization and hypervigilance, remain after suppressive ART, in the presence or absence of T-cell recovery, likely contributing to chronic systemic inflammation.

Chronic Methadone Use Alters the CD8+ T Cell Phenotype In Vivo and Modulates Its Responsiveness Ex Vivo to Opioid Receptor and TCR Stimuli.

Endogenous opioid peptides are released at sites of injury, and their cognate G protein-coupled opioid receptors (ORs) are expressed on immune cells. Although drugs of misuse appropriate ORs, conflicting reports indicate immunostimulatory and immunosuppressive activity, in that opioid users have elevated infection risk, opioids activate innate immune cells, and opioids attenuate inflammation in murine T cell-mediated autoimmunity models. The i.v. use of drugs transmits bloodborne pathogens, particularly viruses, making the study of CD8+ T cells timely. From a cohort of nonuser controls and methadone users, we demonstrate, via t-Stochastic Neighbor Embedding and k-means cluster analysis of surface marker expression, that chronic opioid use alters human CD8+ T cell subset balance, with notable decreases in T effector memory RA+ cells. Studying global CD8+ T cell populations, there were no differences in expression of OR and several markers of functionality, demonstrating the need for finer analysis. Purified CD8+ T cells from controls respond to opioids ex vivo by increasing cytoplasmic calcium, a novel finding for OR signal transduction, likely because of cell lineage. CD8+ T cells from controls exposed to µ-OR agonists ex vivo decrease expression of activation markers CD69 and CD25, although the same markers are elevated in µ-OR-treated cells from methadone users. In contrast to control cells, T cell subsets from methadone users show decreased expression of CD69 and CD25 in response to TCR stimulus. Overall, these results indicate a direct, selective role for opioids in CD8+ T cell immune regulation via their ability to modulate cell responses through the opioid receptors and TCRs.

Decreased Enteric Bacterial Composition and Diversity in South American Crohn's Disease Vary With the Choice of Treatment Strategy and Time Since Diagnosis.

BACKGROUND AND AIMS: The symptomology of Crohn's disease [CD], a chronic inflammatory disease of the digestive tract, correlates poorly with clinical, endoscopic or immunological assessments of disease severity. The prevalence of CD in South America is rising, reflecting changes in socio-economic stability. Many treatment options are available to CD patients, including biological agents and corticosteroids, each of which offers variable efficacy attributed to host genetics and environmental factors associated with alterations in the gut microbiota. METHODS: Based on 16S rRNA gene sequencing and taxonomic differences, we compared the faecal microbial population of Brazilian patients with CD treated with corticosteroid or anti-tumour necrosis factor [anti-TNF] immunotherapy. Faecal calprotectin and plasma sCD14 levels were quantified as markers for local and systemic inflammation, respectively. RESULTS: Anti-TNF treatment led to an increased relative abundance of Proteobacteria and a decreased level of Bacteroidetes. In contrast, corticoid treatment was associated with an increase in the relative abundance of Actinobacteria, which has been linked to inflammation in CD. Disruption of the faecal microbiota was related to decreased bacterial diversity and composition. Moreover, the choice of clinical regimen and time since diagnosis modulate the character of the resulting dysbiosis. CONCLUSIONS: Enteric microbial populations in CD patients who have been treated are modulated by disease pathogenesis, local inflammatory microenvironment and treatment strategy. The dysbiosis that remains after anti-TNF treatment due to decreased bacterial diversity and composition abates restoration of the microbiota to a healthy state, suggesting that the identification and development of new clinical treatments for CD must include their capacity to normalize the gut microbiota.

Presence of Rheumatoid Factor during Chronic HCV Infection Is Associated with Expansion of Mature Activated Memory B-Cells that Are Hypo-Responsive to B-Cell Receptor Stimulation and Persist during the Early Stage of IFN Free Therapy.

Approximately half of those with chronic hepatitis C virus (HCV) infection have circulating rheumatoid factor (RF), and a portion of these individuals develop cryoglobulinemic vasculitis. B cell phenotype/function in relation to RF in serum has been unclear. We examined B cell subset distribution, activation state (CD86), cell cycle state (Ki67), and ex-vivo response to BCR, TLR9 and TLR7/8 stimulation, in chronic HCV-infected donors with or without RF, and uninfected donors. Mature-activated B-cells of HCV-infected donors had lower CD86 expression compared to uninfected donors, and in the presence of RF they also showed reduced CD86 expression in response to BCR and TLR9 stimulation. Additionally, mature activated memory B cells of HCV RF+ donors less commonly expressed Ki67+ than HCV RF- donors, and did not proliferate as well in response to BCR stimulation. Proportions of mature-activated B cells were enhanced, while naïve B-cells were lower in the peripheral blood of HCV-RF+ compared to RF- and uninfected donors. None of these parameters normalize by week 8 of IFN free direct acting antiviral (DAA) therapy in HCV RF+ donors, while in RF- donors, mature activated B cell proportions did normalize. These data indicate that while chronic HCV infection alone results in a lower state of activation in mature activated memory B cells, the presence of RF in serum is associated with a more pronounced state of unresponsiveness and an overrepresentation of these B cells in the blood. This phenotype persists at least during the early time window after removal of HCV from the host.