More Like this

1. Conceptualizing the Gut Thanatomicrobiota in Substance Abuse Disorders

   Javan, GT; Finley, SJ; Scott, L; Visonà, S. (February 2021, Proceedings American Academy of Forensic Sciences)

   null (Ed.)

   In this century, drug abuse continues to be a national crisis. Since 1999, the number of opioid-induced overdoses has increased four-fold to more than 500,000 deaths. The microbiota gut-brain-axis is a bidirectional circuit that links the neural, endocrine, and immunological systems with gut microbial communities. Gut microbiota play significant roles in human mind and behavior, specifically pain perception, learning capacity and memory, mood, and emotion, and anxiolytic effects and temperament. Also, disruptions in the gut microbiome have been associated with substance use disorders. While much research still needs to be performed, elucidating the interplay of gut microbiota in substance abuse disorders may produce promising avenues for future forensic development. The goal of the current study was to determine gut microbiome composition in substance abuse disorder cases using transverse colon tissues of 21 overdose criminal cases versus 19 non-overdose-related cases. The hypothesis was that postmortem samples of the same origin will reveal similar taxonomic relationships. Using weighted UniFrac analysis, drug abuse was found to be a significant factor in determining microbiome similarity (F = 1.93; df = 1, 35; p < 0.048; R2 = 0.05) indicating that there are detectable differences in composition that are attributable to substance abuse. Using unweighted UniFrac, however, sex was instead found to be a significant predictor of microbiome similarity (F = 1.88; df = 1, 30; p = 0.028; R2 = 0.05). A heatmap was generated of the relative abundances of the 30 most prevalent bacteria per case and their associated substance profile. The results revealed that samples of the same origin cluster together, showing a high degree of similarity between samples and a low degree of similarity among samples of different origin. This examination of human transverse colon microflora in decomposing cadavers expands the emerging literature on postmortem microbial communities, which will ultimately contribute to advanced knowledge of putrefaction. 

   more » « less
2. Interaction with refuse piles is associated with co-occurrence of core gut microbiota in workers of the ant Aphaenogaster picea

   https://doi.org/10.1099/acmi.0.000832.v4  

   Pagalilauan, Alison; Pavloudi, Christina; Ospina, Santiago Meneses; Smith, Adam; Saw, Jimmy H (January 2025, Access Microbiology)

   Comparing the diversity of gut microbiota between and within social insect colonies can illustrate interactions between bacterial community composition and host behaviour. In many eusocial insect species, different workers exhibit different task behaviours. Evidence of compositional differences between core microbiota in different worker types could suggest a microbial association with the division of labour among workers. Here, we present the core microbiota ofAphaenogaster piceaant workers with different task behaviours. The genusAphaenogasteris abundant worldwide, yet the associated microbiota of this group is unstudied. Bacterial communities fromAphaenogaster piceagut samples in this study consist of 19 phyla, dominated by Proteobacteria, Cyanobacteria and Firmicutes. Analysis of 16S rRNA gene sequences reveals distinct similarity clustering ofAphaenogaster piceagut bacterial communities in workers that have more interactions with the refuse piles. Though gut bacterial communities of nurse and foraging ants are similar in overall composition and structure, the worker groups differ in relative abundances of dominant taxa. Gut bacterial communities from ants that have more interactions with refuse piles are dominated by amplicon sequence variants associated with Entomoplasmataceae. Interaction with faecal matter via refuse piles seems to have the greatest impact on microbial taxa distribution, and this effect appears to be independent of worker type. This is the first report surveying the gut microbiome community composition ofAphaenogasterants. 

   more » « less
3. Effects of Extended Postmortem Interval on Microbial Communities in Organs of the Human Cadaver

   https://doi.org/https://doi.org/10.3389/fmicb.2020.569630  

   Lutz, H; Vangelatos, A; Gottel, N; Osculati, A; Visona, S; Finley, SJ; Gilbert, J; Javan, GT. (December 2020, Frontiers in microbiology)

   null (Ed.)

   Human thanatomicrobiota studies have shown that microorganisms inhabit and proliferate externally and internally throughout the body and are the primary mediators of putrefaction after death. Yet little is known about the source and diversity of the thanatomicrobiome or the underlying factors leading to delayed decomposition exhibited by reproductive organs. The use of the V4 hypervariable region of bacterial 16S rRNA gene sequences for taxonomic classification (“barcoding”) and phylogenetic analyses of human postmortem microbiota has recently emerged as a possible tool in forensic microbiology. The goal of this study was to apply a 16S rRNA barcoding approach to investigate variation among different organs, as well as the extent to which microbial associations among different body organs in human cadavers can be used to predict forensically important determinations, such as cause and time of death. We assessed microbiota of organ tissues including brain, heart, liver, spleen, prostate, and uterus collected at autopsy from criminal casework of 40 Italian cadavers with times of death ranging from 24 to 432 h. Both the uterus and prostate had a significantly higher alpha diversity compared to other anatomical sites, and exhibited a significantly different microbial community composition from non-reproductive organs, which we found to be dominated by the bacterial orders MLE1-12, Saprospirales, and Burkholderiales. In contrast, reproductive organs were dominated by Clostridiales, Lactobacillales, and showed a marked decrease in relative abundance of MLE1-12. These results provide insight into the observation that the uterus and prostate are the last internal organs to decay during human decomposition. We conclude that distinct community profiles of reproductive versus non-reproductive organs may help guide the application of forensic microbiology tools to investigations of human cadavers. 

   more » « less
4. Cadaver Microbial Signatures of the Submandibular Glands and Thyroid for Forensic Investigations

   Sheree Finley, PhD*; Matteo Moretti, MD; Silvia Visonà, PhD; Gulnaz Javan, PhD* (January 2023, Cadaver Microbial Signatures of the Submandibular Glands and Thyroid for Forensic Investigations)

   The study of the thyroid is an emerging topic, particularly in postmortem microbiome studies, due to the organ’s ability to affect the endocrine system. Also, the submandibular gland is a promising, emerging gland of study due to its position relative to the oral cavity. Previous thanatomicrobiome studies have demonstrated that bacteria belonging to the phyla Firmicutes, Proteobacteria, Bacteroides, and Pseudomonadota predominate internal organs and have been considered an important biomarker for postmortem interval. Further, Clostridium species that dominate in internal organs are linked to the hypoxic change that occurs after death, which leads to the switch of bacteria to become obligate anaerobes. Therefore, obligate anaerobes dominate the body after death due to their ability to thrive off fermentation products. 16S rRNA gene sequencing has been critical in thanatomicrobiome studies, which refers to the human microbiome (microorganisms within the body) after death. Currently, it has not been elucidated regarding the microorganisms that are associated with the decay of submandibular and thyroid glands. We hypothesized that through sequencing of the 16S rRNA gene of the submandibular and thyroid glands, the presence of Firmicutes and Proteobacteria will indicate potential biomarkers for postmortem interval. The present study revealed the postmortem microbial signatures of the submandibular and thyroid glands using the 16S rRNA gene, specifically the V3-V4 hypervariable regions, using universal primers 341F and 805R. We investigated a total of 37 cadavers obtained from ongoing criminal casework, 17 submandibular samples and 20 thyroid samples, and found that there is a correlation between microbial abundance in these postmortem glands. The predominating phyla of interest found in both glands were Firmicutes and Proteobacteria. The predominating genera were Paeniclostridium and Streptococcus in both glands, respectively. Further experimentation of the submandibular and thyroid glands will help to link oral thanatomicrobiome communities to “microbial clock” determinations, thus enhancing postmortem interval estimation. 

   more » « less
5. Development of the intestinal microbiome in cystic fibrosis in early life

   https://doi.org/10.1128/msphere.00046-23  

   Price, Courtney E.; Hampton, Thomas H.; Valls, Rebecca A.; Barrack, Kaitlyn E.; O’Toole, George A.; Madan, Juliette C.; Coker, Modupe O. (August 2023, mSphere)

   Young, Vincent B. (Ed.)

   Cystic fibrosis is a heritable disease that disrupts ion transport at mucosal surfaces, causing a buildup of mucus and dysregulation of microbial communities in both the lungs and the intestines. Persons with CF are known to have dysbiotic gut microbial communities, but the development of these communities over time beginning at birth has not been thoroughly studied. Here, we describe an observation study following the development of the gut microbiome of cwCF throughout the first 4 years of life, during the critical window of both gut microbiome and immune development. Our findings indicate the possibility of the gut microbiota as a reservoir of airway pathogens and a surprisingly early indication of a microbiota associated with inflammatory bowel disease. 

   more » « less