scholarly journals Aging-Induced Dysbiosis of Gut Microbiota as a Risk Factor for Increased Listeria monocytogenes Infection

2021 ◽  
Vol 12 ◽  
Author(s):  
Mohammad S. Alam ◽  
Jayanthi Gangiredla ◽  
Nur A. Hasan ◽  
Tammy Barnaba ◽  
Carmen Tartera
Keyword(s):  
Listeria Monocytogenes ◽  
Young Adult ◽  
Gut Microbiota ◽  
Dna Sequences ◽  
Post Infection ◽  
Bacterial Species ◽  
Case Fatality ◽  
Adult Mice ◽  
Α Diversity ◽  
Old Mice

Invasive foodborne Listeria monocytogenes infection causes gastroenteritis, septicemia, meningitis, and chorioamnionitis, and is associated with high case-fatality rates in the elderly. It is unclear how aging alters gut microbiota, increases risk of listeriosis, and causes dysbiosis post-infection. We used a geriatric murine model of listeriosis as human surrogate of listeriosis for aging individuals to study the effect of aging and L. monocytogenes infection. Aging and listeriosis-induced perturbation of gut microbiota and disease severity were compared between young-adult and old mice. Young-adult and old mice were dosed intragastrically with L. monocytogenes. Fecal pellets were collected pre- and post-infection for microbiome analysis. Infected old mice had higher Listeria colonization in liver, spleen, and feces. Metagenomics analyses of fecal DNA-sequences showed increase in α-diversity as mice aged, and infection reduced its diversity. The relative abundance of major bacterial phylum like, Bacteroidetes and Firmicutes remained stable over aging or infection, while the Verrucomicrobia phylum was significantly reduced only in infected old mice. Old mice showed a marked reduction in Clostridaiceae and Lactobacillaceae bacteria even before infection when compared to uninfected young-adult mice. L. monocytogenes infection increased the abundance of Porphyromonadaceae and Prevotellaceae in young-adult mice, while members of the Ruminococcaceae and Lachnospiraceae family were significantly increased in old mice. The abundance of the genera Blautia and Alistipes were significantly reduced post-infection in young-adult and in old mice as compared to their uninfected counterparts. Butyrate producing, immune-modulating bacterial species, like Pseudoflavonifractor and Faecalibacterium were significantly increased only in old infected mice, correlating with increased intestinal inflammatory mRNA up-regulation from old mice tissue. Histologic analyses of gastric tissues showed extensive lesions in the Listeria-infected old mice, more so in the non-glandular region and fundus than in the pylorus. Commensal species like Lactobacillus, Clostridiales, and Akkermansia were only abundant in infected young-adult mice but their abundance diminished in the infected old mice. Listeriosis in old mice enhances the abundance of butyrate-producing inflammatory members of the Ruminococcaceae/Lachnospiraceae bacteria while reducing/eliminating beneficial commensals in the gut. Results of this study indicate that, aging may affect the composition of gut microbiota and increase the risk of invasive L. monocytogenes infection.

scholarly journals A Combined Analysis of Gut and Skin Microbiota in Infants with Food Allergy and Atopic Dermatitis: A Pilot Study

Nutrients ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1682
Author(s):  
Ewa Łoś-Rycharska ◽  
Marcin Gołębiewski ◽  
Marcin Sikora ◽  
Tomasz Grzybowski ◽  
Marta Gorzkiewicz ◽  
...  
Keyword(s):  
Atopic Dermatitis ◽  
Food Allergy ◽  
Gut Microbiota ◽  
Bacterial Species ◽  
Rrna Gene ◽  
Healthy Children ◽  
Skin Microbiota ◽  
Fecal Samples ◽  
Healthy Infants ◽  
Α Diversity

The gut microbiota in patients with food allergy, and the skin microbiota in atopic dermatitis patients differ from those of healthy people. We hypothesize that relationships may exist between gut and skin microbiota in patients with allergies. The aim of this study was to determine the possible relationship between gut and skin microbiota in patients with allergies, hence simultaneous analysis of the two compartments of microbiota was performed in infants with and without allergic symptoms. Fifty-nine infants with food allergy and/or atopic dermatitis and 28 healthy children were enrolled in the study. The skin and gut microbiota were evaluated using 16S rRNA gene amplicon sequencing. No significant differences in the α-diversity of dermal or fecal microbiota were observed between allergic and non-allergic infants; however, a significant relationship was found between bacterial community structure and allergy phenotypes, especially in the fecal samples. Certain clinical conditions were associated with characteristic bacterial taxa in the skin and gut microbiota. Positive correlations were found between skin and fecal samples in the abundance of Gemella among allergic infants, and Lactobacillus and Bacteroides among healthy infants. Although infants with allergies and healthy infants demonstrate microbiota with similar α-diversity, some differences in β-diversity and bacterial species abundance can be seen, which may depend on the phenotype of the allergy. For some organisms, their abundance in skin and feces samples may be correlated, and these correlations might serve as indicators of the host’s allergic state.

scholarly journals Old Mice Have Less Transcriptional Activation But Similar Periosteal Cell Proliferation Compared to Young‐Adult Mice in Response to in vivo Mechanical Loading

2020 ◽  
Vol 35 (9) ◽  
pp. 1751-1764 ◽  
Author(s):  
Christopher J Chermside‐Scabbo ◽  
Taylor L Harris ◽  
Michael D Brodt ◽  
Ingrid Braenne ◽  
Bo Zhang ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Young Adult ◽  
Mechanical Loading ◽  
Transcriptional Activation ◽  
Adult Mice ◽  
Periosteal Cell ◽  
Old Mice

Free radical injury to skeletal muscles of young, adult, and old mice

1990 ◽  
Vol 258 (3) ◽  
pp. C429-C435 ◽  
Author(s):  
E. Zerba ◽  
T. E. Komorowski ◽  
J. A. Faulkner
Keyword(s):  
Free Radical ◽  
Young Adult ◽  
Free Radical Scavenger ◽  
Radical Scavenger ◽  
Free Radical Damage ◽  
Control Value ◽  
Delayed Onset ◽  
Adult Mice ◽  
Old Mice

We tested the hypotheses that 1) muscles of old mice are more susceptible to injury than muscles of young and adult mice, and 2) secondary or delayed onset injury results from free radical damage. Extensor digitorum longus muscles were injured in situ by lengthening contractions. Injury was assessed by measurement of maximum isometric tetanic force (Po) expressed as a percentage of the control value and by morphological damage. Mice were treated with a free radical scavenger, polyethylene glycol-superoxide dismutase (PEG-SOD). Three days postinjury, the Po of 44% for muscles of nontreated old mice was significantly lower than the Po of 58 and 61% for those of young and adult mice. In each group, the secondary injury at 3 days was alleviated by treatment with PEG-SOD. For treated muscles of young, adult, and old mice, values for Po were 88, 80, and 70%, respectively. We conclude that muscles of old mice are more susceptible to injury than muscles of young or adult mice and that free radicals contribute to the secondary or delayed onset injury.

scholarly journals Neuroinflammation Induced by Surgery Does Not Impair the Reference Memory of Young Adult Mice

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Yanhua Zhao ◽  
Lili Huang ◽  
Huan Xu ◽  
Guangxi Wu ◽  
Mengyi Zhu ◽  
...  
Keyword(s):  
Risk Factor ◽  
Young Adult ◽  
Postoperative Cognitive Dysfunction ◽  
Underlying Mechanism ◽  
Reference Memory ◽  
Behavior Changes ◽  
Spatial Reference ◽  
Adult Mice ◽  
Spatial Reference Memory ◽  
Old Mice

Postoperative cognitive dysfunction (POCD) increases morbidity and mortality after surgery. But the underlying mechanism is not clear yet. While age is now accepted as the top one risk factor for POCD, results from studies investigating postoperative cognitive functions in adults have been controversial, and data about the very young adult individuals are lacking. The present study investigated the spatial reference memory, IL-1β, IL-6, and microglia activation changes in the hippocampus in 2-month-old mice after anesthesia and surgery. We found that hippocampal IL-1βand IL-6 increased at 6 hours after surgery. Microglia were profoundly activated in the hippocampus 6 to 24 hours after surgery. However, no significant behavior changes were found in these mice. These results indicate that although anesthesia and surgery led to neuroinflammation, the latter was insufficient to impair the spatial reference memory of young adult mice.

scholarly journals Septic Stability? Gut Microbiota in Young Adult MICE Maintains Overall Stability After Sepsis Compared to Old Adult MICE

Shock ◽  
2020 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Robert T. Mankowski ◽  
Ryan M. Thomas ◽  
Dijoia B. Darden ◽  
Raad Z. Gharaibeh ◽  
Russell B. Hawkins ◽  
...  
Keyword(s):  
Young Adult ◽  
Gut Microbiota ◽  
Adult Mice ◽  
Overall Stability ◽  
Old Adult

scholarly journals Healthy Brain Aging Modifies Microglial Calcium Signaling In Vivo

2019 ◽  
Vol 20 (3) ◽  
pp. 589 ◽  
Author(s):  
Maria Olmedillas del Moral ◽  
Nithi Asavapanumas ◽  
Néstor Uzcátegui ◽  
Olga Garaschuk
Keyword(s):  
Young Adult ◽  
Brain Aging ◽  
Critical Role ◽  
Low Grade ◽  
Middle Aged ◽  
Senescent Phenotype ◽  
Adult Mice ◽  
Age Related ◽  
Old Mice

Brain aging is characterized by a chronic, low-grade inflammatory state, promoting deficits in cognition and the development of age-related neurodegenerative diseases. Malfunction of microglia, the brain-resident immune cells, was suggested to play a critical role in neuroinflammation, but the mechanisms underlying this malfunctional phenotype remain unclear. Specifically, the age-related changes in microglial Ca2+ signaling, known to be linked to its executive functions, are not well understood. Here, using in vivo two-photon imaging, we characterize intracellular Ca2+ signaling and process extension of cortical microglia in young adult (2–4-month-old), middle-aged (9–11-month-old), and old (18–21-month-old) mice. Our data revealed a complex and nonlinear dependency of the properties of intracellular Ca2+ signals on an animal’s age. While the fraction of cells displaying spontaneous Ca2+ transients progressively increased with age, the frequencies and durations of the spontaneous Ca2+ transients followed a bell-shaped relationship, with the most frequent and largest Ca2+ transients seen in middle-aged mice. Moreover, in old mice microglial processes extending toward an ATP source moved faster but in a more disorganized manner, compared to young adult mice. Altogether, these findings identify two distinct phenotypes of aging microglia: a reactive phenotype, abundantly present in middle-aged animals, and a dysfunctional/senescent phenotype ubiquitous in old mice.

scholarly journals Appropriate exercise level attenuates gut dysbiosis and valeric acid increase to improve neuroplasticity and cognitive function after surgery in mice

2021 ◽  
Author(s):  
Zhongmeng Lai ◽  
Weiran Shan ◽  
Jun Li ◽  
Jia Min ◽  
Xianzhang Zeng ◽  
...  
Keyword(s):  
Growth Factor ◽  
Gut Microbiota ◽  
Learning And Memory ◽  
Memory Impairment ◽  
Postoperative Cognitive Dysfunction ◽  
Valeric Acid ◽  
Low Intensity ◽  
Adult Mice ◽  
Low Intensity Exercise ◽  
Old Mice

AbstractPostoperative cognitive dysfunction (POCD) affects the outcome of millions of patients each year. Aging is a risk factor for POCD. Here, we showed that surgery induced learning and memory dysfunction in adult mice. Transplantation of feces from surgery mice but not from control mice led to learning and memory impairment in non-surgery mice. Low intensity exercise improved learning and memory in surgery mice. Exercise attenuated surgery-induced neuroinflammation and decrease of gut microbiota diversity. These exercise effects were present in non-exercise mice receiving feces from exercise mice. Exercise reduced valeric acid, a gut microbiota product, in the blood. Valeric acid worsened neuroinflammation, learning and memory in exercise mice with surgery. The downstream effects of exercise included attenuating growth factor decrease, maintaining astrocytes in the A2 phenotypical form possibly via decreasing C3 signaling and improving neuroplasticity. Similar to these results from adult mice, exercise attenuated learning and memory impairment in old mice with surgery. Old mice receiving feces from old exercise mice had better learning and memory than those receiving control old mouse feces. Surgery increased blood valeric acid. Valeric acid blocked exercise effects on learning and memory in old surgery mice. Exercise stabilized gut microbiota, reduced neuroinflammation, attenuated growth factor decrease and preserved neuroplasticity in old mice with surgery. These results provide direct evidence that gut microbiota alteration contributes to POCD development. Valeric acid is a mediator for this effect and a potential target for brain health. Low intensity exercise stabilizes gut microbiota in the presence of insult, such as surgery.

scholarly journals The Relationship of Age, Strain and Species to the Reducing Activity of Leukocytes

Blood ◽  
1959 ◽  
Vol 14 (9) ◽  
pp. 1033-1039 ◽  
Author(s):  
ALBINA ANN YAKAITIS
Keyword(s):  
Young Adults ◽  
Young Adult ◽  
Healthy Adult ◽  
Young Rats ◽  
Adult Mice ◽  
Reducing Activity ◽  
Relationship Of ◽  
High Degree ◽  
The Relationship ◽  
Old Mice

Abstract A method is presented for studying the reducing activity of leukocytes of mice and rats using 2-(p-iodophenyl)-3-)p-nitrophenyl)-5-phenyltetrazolium chloride (INT). Between 48.0 per cent and 83.8 per cent of the leukocytes of young adult mice and between 47.8 per cent and 68.0 per cent of the leukocytes of young rats showed formazan formation. Infant mice of C3Hf and BALBf strains had appreciably fewer leukocytes with the ability to reduce tetrazolium than did young adults of their respective strains. Healthy adult mice belonging to the leukemia susceptible AKR strain showed a relatively high degree of leukocytic reduction. Old mice of the C3Hfstrain showed less formazan formation than young adult animals. This decrease was more marked for the male members of the species.

scholarly journals TET1-mediated DNA hydroxy-methylation regulates adult remyelination

2019 ◽  
Author(s):  
Sarah Moyon ◽  
Rebecca Frawley ◽  
Katy LH Marshall-Phelps ◽  
Linde Kegel ◽  
Sunniva MK Bøstrand ◽  
...  
Keyword(s):  
Young Adult ◽  
Brain Function ◽  
Molecular Mechanisms ◽  
Epigenetic Mark ◽  
Adult Mice ◽  
Age Related ◽  
Genome Wide ◽  
Solute Carrier ◽  
Tet Enzymes ◽  
Old Mice

AbstractAdult myelination is essential for brain function and response to injury, but the molecular mechanisms remain elusive. Here we identify DNA hydroxy-methylation, an epigenetic mark catalyzed by Ten-Eleven translocation (TET) enzymes, as necessary for adult myelin repair.While DNA hydroxy-methylation and high levels of TET1 are detected in young adult mice during myelin regeneration after demyelination, this process is defective in old mice. Constitutive or inducible lineage-specific ablation of Tet1 (but not of Tet2) recapitulate the age-related decline of DNA hydroxy-methylation and inefficient remyelination. Genome-wide hydroxy-methylation and transcriptomic analysis identify numerous TET1 targets, including several members of the solute carrier (Slc) gene family. Lower transcripts for Slc genes, including Slc12a2, are observed in Tet1 mutants and old mice and are associated with swelling at the neuroglial interface, a phenotype detected also in zebrafish slc12a2b mutants.We conclude that TET1-mediated DNA hydroxy-methylation is necessary for adult remyelination after injury.

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