Diagnostic and prognostic potential of the microbiome in ovarian cancer treatment response.

Ovarian cancer (OC) is the second most common gynecological malignancy and the fifth leading cause of death due to cancer in women in the United States mainly due to the late-stage diagnosis of this cancer. It is, therefore, critical to identify potential indicators to aid in early detection and diagnosis of this disease. We investigated the microbiome associated with OC and its potential role in detection, progression as well as prognosis of the disease. We identified a distinct OC microbiome with general enrichment of several microbial taxa, including Dialister, Corynebacterium, Prevotella, and Peptoniphilus in the OC cohort in all body sites excluding stool and omentum which were not sampled from the benign cohort. These taxa were, however, depleted in the advanced-stage and high-grade OC patients compared to early-stage and low-grade OC patients suggestive of decrease accumulation in advanced disease and could serve as potential indicators for early detection of OC. Similarly, we also observed the accumulation of these mainly pathogenic taxa in OC patients with adverse treatment outcomes compared to those without events and could also serve as potential indicators for predicting patients' responses to treatment. These findings provide important insights into the potential use of the microbiome as indicators in (1) early detection of and screening for OC and (2) predicting patients' response to treatment. Given the limited number of patients enrolled in the study, these results would need to be further investigated and confirmed in a larger study.

Large Comparative Analyses of Primate Body Site Microbiomes Indicate that the Oral Microbiome Is Unique among All Body Sites and Conserved among Nonhuman Primates.

The study of the mammalian microbiome serves as a critical tool for understanding host-microbial diversity and coevolution and the impact of bacterial communities on host health. While studies of specific microbial systems (e.g., in the human gut) have rapidly increased, large knowledge gaps remain, hindering our understanding of the determinants and levels of variation in microbiomes across multiple body sites and host species. Here, we compare microbiome community compositions from eight distinct body sites among 17 phylogenetically diverse species of nonhuman primates (NHPs), representing the largest comparative study of microbial diversity across primate host species and body sites. Analysis of 898 samples predominantly acquired in the wild demonstrated that oral microbiomes were unique in their clustering, with distinctive divergence from all other body site microbiomes. In contrast, all other body site microbiomes clustered principally by host species and differentiated by body site within host species. These results highlight two key findings: (i) the oral microbiome is unique compared to all other body site microbiomes and conserved among diverse nonhuman primates, despite their considerable dietary and phylogenetic differences, and (ii) assessments of the determinants of host-microbial diversity are relative to the level of the comparison (i.e., intra-/inter-body site, -host species, and -individual), emphasizing the need for broader comparative microbial analyses across diverse hosts to further elucidate host-microbial dynamics, evolutionary and biological patterns of variation, and implications for human-microbial coevolution. IMPORTANCE The microbiome is critical to host health and disease, but much remains unknown about the determinants, levels, and evolution of host-microbial diversity. The relationship between hosts and their associated microbes is complex. Most studies to date have focused on the gut microbiome; however, large gaps remain in our understanding of host-microbial diversity, coevolution, and levels of variation in microbiomes across multiple body sites and host species. To better understand the patterns of variation and evolutionary context of host-microbial communities, we conducted one of the largest comparative studies to date, which indicated that the oral microbiome was distinct from the microbiomes of all other body sites and convergent across host species, suggesting conserved niche specialization within the Primates order. We also show the importance of host species differences in shaping the microbiome within specific body sites. This large, comparative study contributes valuable information on key patterns of variation among hosts and body sites, with implications for understanding host-microbial dynamics and human-microbial coevolution.

Amplification of Femtograms of Bacterial DNA Within 3 h Using a Digital Microfluidics Platform for MinION Sequencing.

Whole genome sequencing is emerging as a promising tool for the untargeted detection of a broad range of microbial species for diagnosis and analysis. However, it is logistically challenging to perform the multistep process from sample preparation to DNA amplification to sequencing and analysis within a short turnaround time. To address this challenge, we developed a digital microfluidic device for rapid whole genome amplification of low-abundance bacterial DNA and compared results with conventional in-tube DNA amplification. In this work, we chose Corynebacterium glutamicum DNA as a bacterial target for method development and optimization, as it is not a common contaminant. Sequencing was performed in a hand-held Oxford Nanopore Technologies MinION sequencer. Our results show that using an in-tube amplification approach, at least 1 pg starting DNA is needed to reach the amount required for successful sequencing within 2 h. While using a digital microfluidic device, it is possible to amplify as low as 10 fg of C. glutamicum DNA (equivalent to the amount of DNA within a single bacterial cell) within 2 h and to identify the target bacterium within 30 min of MinION sequencing-100× lower than the detection limit of an in-tube amplification approach. We demonstrate the detection of C. glutamicum DNA in a mock community DNA sample and characterize the limit of bacterial detection in the presence of human cells. This approach can be used to identify microbes with minute amounts of genetic material in samples depleted of human cells within 3 h.

The Gut Microbiota Communities of Wild Arboreal and Ground-Feeding Tropical Primates Are Affected Differently by Habitat Disturbance.

Human exploitation and destruction of tropical resources are currently threatening innumerable wild animal species, altering natural ecosystems and thus, food resources, with profound effects on gut microbiota. Given their conservation status and the importance to tropical ecosystems, wild nonhuman primates make excellent models to investigate the effect of human disturbance on the diversity of host-associated microbiota. Previous investigations have revealed a loss of fecal bacterial diversity in primates living in degraded compared to intact forests. However, these data are available for a limited number of species, and very limited information is available on the fungal taxa hosted by the gut. Here, we estimated the diversity and composition of gut bacterial and fungal communities in two primates living sympatrically in both human-modified and pristine forests in the Udzungwa Mountains of Tanzania. Noninvasively collected fecal samples of 12 groups of the Udzungwa red colobus (Procolobus gordonorum) (n = 89), a native and endangered primate (arboreal and predominantly leaf-eating), and five groups of the yellow baboon (Papio cynocephalus) (n = 69), a common species of least concern (ground-feeding and omnivorous), were analyzed by the V1-V3 region of the 16S rRNA gene (bacterial) and ITS1-ITS2 (fungal) sequencing. Gut bacterial diversities were associated with habitat in both species, most likely depending on their ecological niches and associated digestive physiology, dietary strategies, and locomotor behavior. In addition, fungal communities also show distinctive traits across hosts and habitat type, highlighting the importance of investigating this relatively unexplored gut component.IMPORTANCE Gut microbiota diversity has become the subject of extensive research in human and nonhuman animals, linking diversity and composition to gut function and host health. Because wild primates are good indicators of tropical ecosystem health, we developed the idea that they are a suitable model to observe the consequences of advancing global change (e.g., habitat degradation) on gut microbiota. So far, most of the studies focus mainly on gut bacteria; however, they are not the only component of the gut: fungi also serve essential functions in gut homeostasis. Here, for the first time, we explore and measure diversity and composition of both bacterial and fungal microbiota components of two tropical primate species living in highly different habitat types (intact versus degraded forests). Results on their microbiota diversity and composition are discussed in light of conservation issues and potential applications.

Extensive variability in the gut microbiome of a highly-specialized and critically endangered lemur species across sites.

Deforestation continues to jeopardize Malagasy primates as viable habitats become smaller, more fragmented, and more disturbed. This deforestation can lead to changes in diet, microhabitat, and gene flow between populations of endangered species, and it remains unclear how these changes may affect gut microbiome (GM) characteristics. The black-and-white ruffed lemur (Varecia variegata), which is among Madagascar's most threatened lemur species, provides a critical model for understanding the relationships between historical and on-going deforestation (habitat disturbance), feeding ecology, and GM composition and diversity. We studied four populations inhabiting two rainforests (relatively pristine vs. highly disturbed) in southeastern Madagascar. We conducted full-day focal animal behavioral follows and collected fecal samples opportunistically across a three-month period. Our results indicate that lemurs inhabiting sites characterized by habitat disturbance and low dietary diversity exhibited reduced gut microbial alpha diversity. We also show that these same factors were associated with high community dissimilarity using weighted and unweighted UniFrac metrics. Finally, an indicator species analysis showed that the most pristine site was characterized by an abundance of methanogenic archaea. While it is impossible to disentangle the relative contributions of each confounding variable presented by our sampling design, these results provide crucial information about GM variability, thereby underscoring the importance of monitoring endangered species at the population-level.

Variations in the microbiome due to storage preservatives are not large enough to obscure variations due to factors such as host population, host species, body site, and captivity.

The study of the primate microbiome is critical in understanding the role of the microbial community in the host organism. To be able to isolate the main factors responsible for the differences observed in microbiomes within and between individuals, confounding factors due to technical variations need to be removed. To determine whether alterations due to preservatives outweigh differences due to factors such as host population, host species, body site, and habitat, we tested three methods (no preservative, 96% ethanol, and RNAlater) for preserving wild chimpanzee (fecal), wild lemur (fecal), wild vervet monkey (rectal, oral, nasal, otic, vaginal, and penile), and captive vervet monkey (rectal) samples. All samples were stored below - 20°C (short term) at the end of the field day and then at - 80°C until DNA extraction. Using 16S rRNA gene sequencing, we show a significant preservative effect on microbiota composition and diversity. Samples stored in ethanol and RNAlater appear to be less different compared with samples not stored in any preservative (none). Our differential analysis revealed significantly higher amounts of Enterococcaceae and Family XI in no preservative samples, Prevotellaceae and Spirochaetaceae in ethanol and RNAlater preserved samples, Oligosphaeraceae in ethanol-preserved samples, and Defluviitaleaceae in RNAlater preserved samples. While these preservative effects on the microbiome are not large enough to remove or outweigh the differences arising from biological factors (e.g., host species, body site, and habitat differences) they may promote misleading interpretations if they have large enough effect sizes compared to the biological factors (e.g., host population).

Global phylogeography and ancient evolution of the widespread human gut virus crAssphage.

Microbiomes are vast communities of microorganisms and viruses that populate all natural ecosystems. Viruses have been considered to be the most variable component of microbiomes, as supported by virome surveys and examples of high genomic mosaicism. However, recent evidence suggests that the human gut virome is remarkably stable compared with that of other environments. Here, we investigate the origin, evolution and epidemiology of crAssphage, a widespread human gut virus. Through a global collaboration, we obtained DNA sequences of crAssphage from more than one-third of the world's countries and showed that the phylogeography of crAssphage is locally clustered within countries, cities and individuals. We also found fully colinear crAssphage-like genomes in both Old-World and New-World primates, suggesting that the association of crAssphage with primates may be millions of years old. Finally, by exploiting a large cohort of more than 1,000 individuals, we tested whether crAssphage is associated with bacterial taxonomic groups of the gut microbiome, diverse human health parameters and a wide range of dietary factors. We identified strong correlations with different clades of bacteria that are related to Bacteroidetes and weak associations with several diet categories, but no significant association with health or disease. We conclude that crAssphage is a benign cosmopolitan virus that may have coevolved with the human lineage and is an integral part of the normal human gut virome.

Participation, representation, and shared experiences of women scholars in biological anthropology.

American Association of Physical Anthropologists (AAPA) membership surveys from 1996 and 1998 revealed significant gender disparities in academic status. A 2014 follow-up survey showed that gender equality had improved, particularly with respect to the number of women in tenure-stream positions. However, although women comprised 70% of AAPA membership at that time, the percentage of women full professors remained low. Here, we continue to consider the status of women in biological anthropology by examining the representation of women through a quantitative analysis of their participation in annual meetings of the AAPA during the past 20 years. We also review the programmatic goals of the AAPA Committee on Diversity Women's Initiative (COD-WIN) and provide survey results of women who participated in COD-WIN professional development workshops. Finally, we examine the diversity of women's career paths through the personal narratives of 14 women biological anthropologists spanning all ranks from graduate student to Professor Emeritus. We find that over the past 20 years, the percentage of women first authors of invited symposia talks has increased, particularly in the sub-disciplines of bioarchaeology, genetics, and paleoanthropology. The percentage of women first authors on contributed talks and posters has also increased. However, these observed increases are still lower than expected given the percentage of graduate student women and women at the rank of assistant and associate professor. The personal narratives highlight first-hand the impact of mentoring on career trajectory, the challenges of achieving work-life satisfaction, and resilience in the face of the unexpected. We end with some suggestions for how to continue to improve equality and equity for women in biological anthropology.