Biology subjects

Jacobs, J. P.

Publications and source records attributed to Jacobs, J. P..

5 recordsLinked to original sources

bioRxiv2026

Use of Metagenomic Reference Materials to Compare Lysis and Extraction Methods Against a Known Input

Inconsistent cellular lysis is a major source of inaccuracy in microbial analysis; there is a need to develop objective and standardized evaluation of lysis efficiency across diverse methods. Using a mock microbial community as a ground truth, we built a bioinformatic and experimental toolkit for this purpose, comparing the performance of chemical, thermal, enzymatic, and various physical lysis protocols. We evaluated over 150 lysis conditions and observed the highest performance from mechanically- and materially-optimized bead-based approaches. To extend these findings to a practical setting, we demonstrated that the Firmicutes to Bacteroides ratio, a frequently used compositional metric in gut microbiome analysis is biased heavily by insufficient lysis, indicating the importance of benchmarking ongoing methodological development.

microbiology↗

bioRxiv2025

Gut microbial interaction networks control autoimmunity to neuroretina

The gut microbiome influences the development of immune-mediated inflammatory diseases, including autoimmune uveitis, a sight-threatening ocular inflammation driven by retina-specific T cells1. Using a model of spontaneous autoimmune uveitis (sEAU) we showed that gut commensals provide immune stimuli that trigger disease2. Here we report that uveitis-promoting microbes are present in human gut flora and that colonization of germ-free (GF) mice with commensals from healthy human donors was sufficient to provoke disease. Severity of sEAU correlated with expansion of Akkermansia and contraction of short-chain fatty acid (SCFA)-producing Firmicutes, followed by decreased SCFA levels and a dominant gut Th1 effector response. Mechanistic gain-of-function experiments, enriching GF sEAU mice with Akkermansia, reproduced these microbiome, metabolite and immune phenotype shifts, and exacerbated disease, suggesting that Akkermansia promotes autoimmunity by outcompeting SCFA-producers and enhancing Th1-type responses. An inverse correlation between Akkermansia (Verrucomicrobia) and Firmicutes was also present in patients with uveitis, multiple sclerosis and Crohns disease. These findings reveal a stereotypic gut microbial interaction network that regulates systemic immune balance, and may represent an ecologically conserved mechanism through which the gut microbiome modulates autoimmune and inflammatory diseases.

immunology↗

bioRxiv2024

The ZIP8 A391T Crohn's disease-linked risk variant induces colonic metal ion dyshomeostasis, microbiome compositional shifts, and inflammation

The pathogenesis of Crohns disease involves genetic and environmental factors, with the gut microbiome playing a crucial role. The Crohns disease-associated variant rs13107325 in the SLC39A8 gene results in an A391T substitution in the ZIP8 metal ion transporter and has previously been linked to alterations in the colonic microbiome in variant carriers. We hypothesized that the A391T substitution alters metal ion homeostasis in the colonic mucosal-luminal interface, thereby inducing dysbiosis which may promote intestinal inflammation. To evaluate this hypothesis, we generated a SLC39A8 A393T mouse model (matching human A391T). Consistent with an effect of the variant on ZIP8 function, homozygous A393T mice exhibited increased cobalt in the colonic mucosa, but reduced iron, zinc, manganese, cobalt, copper, and cadmium in the colonic lumen. We performed 16S rRNA gene sequencing of colon samples and histological scoring of colon tissue collected from the SLC39A8 A393T mouse model at different ages. We identified variant-linked effects on microbiome beta diversity in 2-month, 3-4 month, and 12-month old mice and spontaneous intestinal inflammation in 10-month but not 5-month old mice. Predicted pathway analysis of the microbiome samples revealed differential enrichment of iron-, zinc- and cobalt-dependent pathways in A393T mice compared to wild-type controls. These results suggest that the variant in SLC39A8 primarily restricts metal availability to the microbiota, resulting in compositions that can adapt to the environment, and that A393T-linked dysbiosis occurs prior to the onset of inflammation. This study paves the way for future studies investigating risk variants as microbiome-disease modifiers. NEW & NOTEWORTHYMice recapitulating the human A391T Crohns disease-linked risk variant in the SLC39A8-encoded ZIP8 transporter exhibit reduced luminal trace metals and an altered microbiome composition. The microbiome compositional shift occurs prior to the onset of spontaneous colonic inflammation. This study supports an emerging paradigm by which genetic risk for inflammatory bowel disease may confer disease susceptibility through modulation of the gut microbiome.

genomics↗

bioRxiv2020

Liver Electrical Impedance Tomography for Early Identification of Fatty Infiltrate in Obesity

Non-alcoholic fatty liver disease (NAFLD) is endemic in developed countries and is one of the most common causes of cardiometabolic diseases in overweight/obese individuals. While liver biopsy or magnetic resonance imaging (MRI) is the current gold standard to diagnose NAFLD, the former is prone to bleeding and the latter is costly. We hereby demonstrated liver electrical impedance tomography (EIT) as a non-invasive and portable detection method for fatty infiltrate. We enrolled 19 subjects (15 females and 4 males; 27 to 74 years old) to undergo liver MRI scans, followed by EIT measurements via a multi-electrode array. The liver MRI scans provided subject-specific a priori knowledge of the liver boundary conditions for segmentation and EIT reconstruction, and the 3-D multi-echo MRI data quantified liver proton-density fat fraction (PDFF%) as a recognized reference standard for validating liver fat infiltrate. Using acquired voltage data and the reconstruction algorithm for the EIT imaging, we computed the absolute conductivity distribution of abdomen in 2-D. Correlation analyses were performed to compare the individual EIT conductivity vs. MRI PDFF with their demographics in terms of gender, BMI (kg{middle dot}m-2), age (years), waist circumference (cm), height (cm), and weight (kg). Our results indicate that EIT conductivity (S{middle dot}m-1) and liver MRI for PDFF were not correlated with the demographics, whereas the decrease in EIT conductivity was correlated with the increase in MRI PDFF (R = - 0.69, p= 0.003). Thus, EIT conductivity holds promise for developing a non-invasive, portable, and quantitative method to detect fatty liver disease.

bioengineering↗

bioRxiv2018

Inflammatory bowel disease microbiotas alter gut CD4 T-cell homeostasis and drive colitis in mice

To examine the functional contribution of Inflammatory Bowel Disease (IBD) microbes to immune homeostasis and colitis, we colonized unchallenged and colitis-susceptible germ-free mice with over twenty human intestinal microbiotas from healthy and IBD donors. Compared to healthy microbiotas, IBD microbiotas led to expanded ROR{gamma}t+Th17 cells and reduced ROR{gamma}t+Treg in the gut of unchallenged gnotobiotic mice and increased disease severity in colitis-susceptible mice. The proportions of ROR{gamma}t+Th17 and ROR{gamma}t+Treg induced by each microbiota were highly predictive of the human disease status and strongly correlated with disease severity in colitis-susceptible mice colonized with the same human microbiotas. The transmittable functional potential of IBD microbes suggests a mechanism for a microbial contribution to IBD pathogenesis and a potential route for its treatment and prevention.

immunology↗