Policy implications of the microbiota-gut-brain axis.

The microbiota-gut-brain axis facilitates communication between the gut microbiota and the brain. It has implications for health and environmental policy. Microbiota are linked to neurological and metabolic disorders, and our exposure to health-promoting microbiota depends on environmental quality. Microbiota-gut-brain axis interventions could inform policy initiatives to address systemic health issues.

Factors Associated with Vaginal Lactobacillus Predominance Among African American Women Early in Pregnancy.

Background: Vaginal Lactobacillus is considered protective of some adverse reproductive health outcomes, including preterm birth. However, factors that increase or decrease the likelihood of harboring Lactobacillus in the vaginal microbiome remain largely unknown. In this study, we sought to identify risk and protective factors associated with vaginal Lactobacillus predominance within a cohort of pregnant African American women. Materials and Methods: Vaginal microbiome samples were self-collected by African American women (N = 436) during their 8-14th week of pregnancy. Sociodemographic information and measures of health behaviors, including substance use, antibiotic exposure, sexual practices, frequency of vaginal intercourse, and the use of vaginal products, were collected through participant self-report. The V3-V4 region of the 16S rRNA gene was targeted for amplification and sequencing using Illumina HiSeq, with bacterial taxonomy assigned using the PECAN classifier. Univariate and a series of multivariate logistic regression models identified factors predictive of diverse vaginal microbiota or Lactobacillus predominance. Results: Participants who used marijuana in the past 30 days (aOR 1.80, 95% CI 1.08-2.98) were more likely to have diverse non-Lactobacillus-predominant vaginal microbiota, as were women not living with their partners (aOR 1.90, 95% CI 1.20-3.01). Cohabitating or marijuana usage were not associated with type of Lactobacillus (non-iners Lactobacillus vs. Lactobacillus iners) predominance (aOR 1.11, 95% CI 0.52-2.38 and aOR 0.56, 95% CI 0.21-1.47, respectively). Conclusions: Living with a partner is conducive to vaginal Lactobacillus predominance. As such, cohabitation may be in important covariate to consider in vaginal microbiome studies.

Shiftwork, functional bowel symptoms, and the microbiome.

BACKGROUND: There are about 15 million Americans working full-time on evening, night, or rotating shifts. Between 48% and 81.9% of those working rotating or night shifts report abdominal pain, constipation, diarrhea and other symptoms of functional bowel disorders. The basis for this high prevalence of functional bowel disorders, including irritable bowel syndrome (IBS), among shift workers is unknown. Animal studies, however, suggest that circadian disruption, similar to that in shift workers, may contribute to the development of GI complaints among shift workers by altering the composition and normal diurnal rhythmicity of the resident intestinal microbes. Therefore, the present study was designed to determine if there were differences in (1) composition and diversity of the microbiome of night shift workers compared to day shift workers; and (2) the composition and diversity of the microbiome among shift workers experiencing functional bowel symptoms compared to shift workers who did not experience functional bowel symptoms. METHODS: Fifty-one full time staff nurses who worked either 12-hour day or night shifts completed demographic information, and the Rome III IBS module. They also collected two samples of gut microbiota before the beginning and at the end of their last work shift on day 14, using validated field-tested methods consistent with the Human Microbiome Project. After DNA extraction, 16S rRNA sequencing and assignment to the genus level was completed, samples were then compared to determine if there were (1) differences in the diversity and profile of the microbiome by shift type; (2) if there were differences in the microbiome by time of day for collection; and (3) whether there were differences in the diversity and profile of the microbiome of nurses with IBS and those without IBS. RESULTS: There were no differences in alpha or beta diversity of gut microbiota when specimens from day and night shift nurses were compared. There were however marginal differences in beta diversity when specimens collected at the beginning and end of the shifts were compared, with seven OTUs being differentially abundant when collected from day shift workers in the evening. There were also three OTUs to be differentially abundant in participants reporting IBS symptoms.

Strain Structure and Dynamics Revealed by Targeted Deep Sequencing of the Honey Bee Gut Microbiome.

Host-associated microbiomes can be critical for the health and proper development of animals and plants. The answers to many fundamental questions regarding the modes of acquisition and microevolution of microbiome communities remain to be established. Deciphering strain-level dynamics is essential to fully understand how microbial communities evolve, but the forces shaping the strain-level dynamics of microbial communities remain largely unexplored, mostly because of methodological issues and cost. Here, we used targeted strain-level deep sequencing to uncover the strain dynamics within a host-associated microbial community using the honey bee gut microbiome as a model system. Our results revealed that amplicon sequencing of conserved protein-coding gene regions using species-specific primers is a cost-effective and accurate method for exploring strain-level diversity. In fact, using this method we were able to confirm strain-level results that have been obtained from whole-genome shotgun sequencing of the honey bee gut microbiome but with a much higher resolution. Importantly, our deep sequencing approach allowed us to explore the impact of low-frequency strains (i.e., cryptic strains) on microbiome dynamics. Results show that cryptic strain diversity is not responsible for the observed variations in microbiome composition across bees. Altogether, the findings revealed new fundamental insights regarding strain dynamics of host-associated microbiomes.IMPORTANCE The factors driving fine-scale composition and dynamics of gut microbial communities are poorly understood. In this study, we used metagenomic amplicon deep sequencing to decipher the strain dynamics of two key members of the honey bee gut microbiome. Using this high-throughput and cost-effective approach, we were able to confirm results from previous large-scale whole-genome shotgun (WGS) metagenomic sequencing studies while also gaining additional insights into the community dynamics of two core members of the honey bee gut microbiome. Moreover, we were able to show that cryptic strains are not responsible for the observed variations in microbiome composition across bees.

A Comparison of the Bacterial Nasal Microbiome in Allergic Rhinitis Patients Before and After Immunotherapy.

OBJECTIVES/HYPOTHESIS: Recent research has examined the nasal microbiome in rhinosinusitis and nondiseased states. Given immunologic alterations in allergic rhinitis (AR) and after allergen immunotherapy (IT), we evaluated the nasal microbiome in these conditions. STUDY DESIGN: Cross-sectional comparison. METHODS: In this cross-sectional study, nasal swabs for microbiome analysis were collected from three patient groups: IT-naïve AR patients, AR patients undergoing IT for greater than 12 months, and a control group without sinonasal inflammatory disease. RESULTS: Nasal swabs were successfully collected for 14 IT-naïve AR patients, 20 post-IT patients, and 17 controls. The α diversity showed a statistical difference in evenness but not in richness amongst samples, whereas the ß-diversity was significantly different between groups. Corynebacterium and Staphylococcus were the most prevalent bacteria across all groups. CONCLUSIONS: ß-diversity was found to be significantly different across the three groups, but the AR groups were found to be more similar to each other than to the controls. Although there is symptomatic improvement in the AR group undergoing IT, the microbiome does not appear to transition to a healthy microbiome composition. LEVEL OF EVIDENCE: 4 Laryngoscope, 2020.

Microbes and the Mind: How Bacteria Shape Affect, Neurological Processes, Cognition, Social Relationships, Development, and Pathology.

Recent data suggest that the human body is not so exclusively human after all. Specifically, humans share their bodies with approximately 10 trillion microorganisms, collectively known as the microbiome. Chief among these microbes are bacteria, and there is a growing consensus that they are critical to virtually all facets of normative functioning. This article reviews the ways in which bacteria shape affect, neurological processes, cognition, social relationships, development, and psychological pathology. To date, the vast majority of research on interactions between microbes and humans has been conducted by scientists outside the field of psychology, despite the fact that psychological scientists are experts in many of the topics being explored. This review aims to orient psychological scientists to the most relevant research and perspectives regarding the microbiome so that we might contribute to the now widespread, interdisciplinary effort to understand the relationship between microbes and the mind.