Search bioRxivSearch

bioRxiv · 10.1101/730747

Does microbiome-associated disease affect the inter-subject heterogeneity of human microbiome?

Abstract

Space is a critical and also challenging frontier in human microbiome research. It has been argued that lack of consideration of scales beyond individual and ignoring of microbe dispersal are two crucial roadblocks in preventing deep understanding of the heterogeneity of human microbiome. Assessing and interpreting the spatial distribution (dispersal) of microbes explicitly are particularly challenging, but implicit approaches such as Taylors power law (TPL) can still be effective and offer significant insights into the heterogeneity in abundance and distribution of human microbiomes. Here, we investigate the relationship between human microbiome-associated diseases (MADs) and the inter-subject microbiome heterogeneity, or heterogeneity-disease relationship (HDR), by harnessing the power of TPL extensions and by analyzing a big dataset of 25 MAD studies covering all five major microbiome habitats and majority of the high-profile MADs including obesity and diabetes. Our HDR analysis revealed that in approximately 10%-17% of the cases, disease effects were significant--the healthy and diseased cohorts exhibited statistically significant differences. In majority of the MAD cases, the microbiome was sufficiently resilient to endure the disturbances of MADs. Furthermore, comparative analysis with traditional DDR (diversity-disease relationship) results is presented. We postulate that HDR reveals evolutionary characteristics because it utilizes the TPL parameter that implicitly characterizes spatial behavior (dispersion), which is primarily shaped by microbe-host co-evolution and is more robust against disturbances including diseases, while diversity in DDR analysis is primarily an ecological-scale characteristic and is less robust against diseases. Nevertheless, both HDR and DDR cross-verified remarkable resilience of human microbiomes against MADs.\n\nImportanceIt has been argued that lack of consideration of scales beyond individual and ignoring of microbe dispersal are two crucial roadblocks in preventing deep understanding of the heterogeneity of human microbiome. Assessing and interpreting the spatial distribution (dispersal) of microbes explicitly are particularly challenging, but implicit approaches such as Taylors power law (TPL) can still be effective. Here, we investigate the relationship between human microbiome-associated diseases (MADs) and the inter-subject microbiome heterogeneity, or heterogeneity-disease relationship (HDR), by harnessing the power of TPL extensions and by analyzing a big dataset of 25 MAD studies covering all five major microbiome habitats and majority of the high-profile MADs including obesity and diabetes. We postulate that HDR reveals evolutionary characteristics because it utilizes the TPL parameter that implicitly characterizes spatial behavior (dispersion), which is primarily shaped by microbe-host co-evolution and is more robust against disturbances including diseases than the traditional diversity-disease relationship (DDR).

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Ma, Z., Li, L.. 2019-08-09. Does microbiome-associated disease affect the inter-subject heterogeneity of human microbiome?. https://doi.org/10.1101/730747

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

A conserved cysteine-histidine-glutamate metal site identifies DUF501 (Rv1025), an essential uncharacterised protein family of Mycobacterium tuberculosis, as a candidate metalloenzyme and drug target

A substantial fraction of the Mycobacterium tuberculosis proteome remains functionally uncharacterised. Rv1025, a 155-residue protein carrying the domain of unknown function DUF501 (Pfam PF04417), is essential by transposon mutagenesis and vulnerable by CRISPR interference, an attractive but neglected drug target, yet has never been functionally described. The family (4,370 proteins, no Gene Ontology term, no solved structure) is uncharacterised across all organisms and essential in three Actinobacterial genera. A Foldseek search of the AlphaFold model against complete structural databases finds no significant homolog, indicating a novel fold. The operon eno-divIC-Rv1025-ppx2 is conserved across the Actinobacteria phylum, yet AlphaFold-Multimer finds no direct complex between Rv1025 and its neighbour DivIC. Instead, conservation across 8,700 homologous sequences reveals a near-invariant Cys113-His115-Glu59 cluster forming a pocket. Holo AlphaFold3 predictions with Zn, Fe and Mn confidently place a divalent metal on this triad at 2.25-2.47 A; mutating the triad relocates the metal, and an independent backbone-geometry predictor recovers the same site, confirming specificity. The triad is universal across the family: present in all 1,472 near-complete bacterial sequences of the Pfam alignment, with no non-conservative substitution among the 2,228 sequences examined, a defining feature of bacterial DUF501 rather than a mycobacterial peculiarity. We propose that DUF501 is a metal-binding protein and candidate metalloenzyme, the first functional hypothesis for this family, whose conserved, essential metal pocket is a promising drug target. As the predictions build on a conservation-defined site within a fully computational study, they are supportive rather than proof of metal occupancy and warrant experimental validation.

microbiology

Mycoplasmal endosymbionts of Trichomonas vaginalis are associated with reduced risk for Chlamydia trachomatis endometrial infection in asymptomatic, coinfected, women.

Trichomonas vaginalis is a protozoan parasite that causes trichomoniasis, the most common curable non-viral sexually transmitted infection, and Chlamydia trachomatis is a bacterial pathogen that can ascend to the upper genital tract and cause pelvic inflammatory disease, infertility, and ectopic pregnancy. T. vaginalis harbors bacterial endosymbionts, including Candidatus Malacoplasma girerdii, an obligate symbiont, and Metamycoplasma hominis, which can live freely or symbiotically. In a 16S rRNA sequencing study of the cervicovaginal microbiome of women at high risk for chlamydial infection, Ca. M. girerdii abundance was one of 13 features predicting lack of chlamydial spread to the endometrium, despite no direct association between T. vaginalis infection and reduced chlamydial ascension. Investigating the relationship between these microorganisms further, we found that T. vaginalis vaginal abundance correlated positively with chlamydial burden in women whose infection was confined to the cervix, while a nonsignificant inverse relationship was seen in women with endometrial spread. Among participants with high chlamydial burden, Ca. M. girerdii was detected exclusively in women without endometrial infection. Both endosymbionts trended toward more frequent detection, and higher abundance, in coinfected women without endometrial spread, while M. hominis abundance correlated strongly with T. vaginalis burden in this group. These findings suggest that mycoplasmal endosymbionts of T. vaginalis, rather than T. vaginalis itself, are microbial factors limiting chlamydial ascension, and point to a three-way interaction between parasite, endosymbiont, and bacterial pathogen that shapes upper genital tract C. trachomatis infection risk.

microbiology

Understanding the physiological alterations of Vibrio cholerae upon exposure to L-ascorbic acid

The scourge of cholera remains a major global public health threat. It affects up to 4 million people worldwide and causes tens of thousands of deaths each year. The disease is experiencing a concerning resurgence in many parts of Africa, the Middle East, and Asia. To effectively tackle cholera and circumvent rising antimicrobial resistance, targeted biological and preventive approaches, complementing traditional rehydration, are urgently needed. In this regard, our group has demonstrated the efficacy of L-ascorbic acid in controlling the growth and pathogenesis of Vibrio cholerae in vitro. The present work further provides a mechanistic elucidation of the L-ascorbic acid-mediated physiological changes in V. cholerae and also bolsters such a non-antibiotic approach to control cholera.

microbiology