Longevity, cellular senescence and the gut microbiome: lessons to be learned from crocodiles

Population dynamics model for aging

The chronological age used in demography describes the linear evolution of the life of a living being. The chronological age cannot give precise information about the exact developmental stage or aging processes an organism has reached. On the contrary, the biological age (or epigenetic age) represents the true evolution of the tissues and organs of the living being. Biological age is not always linear and sometimes proceeds by discontinuous jumps. These jumps can be negative (we then speak of rejuvenation) or positive (in the event of premature aging), and they can be dependent on endogenous events such as pregnancy (negative jump) or stroke (positive jump) or exogenous ones such as surgical treatment (negative jump) or infectious disease (positive jump). The article proposes a mathematical model of the biological age by defining a valid model for the two types of jumps (positive and negative). The existence and uniqueness of the solution are solved, and its temporal dynamic is analyzed using a moments equation. We also provide some individual-based stochastic simulations.

Gut microbiome of Crocodylus porosus and cellular stress: inhibition of nitric oxide, interleukin 1-beta, tumor necrosis factor-alpha, and prostaglandin E2 in cerebrovascular endothelial cells

Crocodiles are renowned for their resilience and capacity to withstand environmental stressors, likely influenced by their unique gut microbiome. In this study, we determined whether selected gut bacteria of Crocodylus porosus exhibit anti-inflammatory effects in response to stress, by measuring nitric oxide release, interleukin 1-beta, tumor necrosis factor-alpha, and prostaglandin E2 in cerebrovascular endothelial cells. Using the Griess assay, the findings revealed that among several C. porosus gut bacterial isolates, the conditioned media containing the metabolites of two bacterial strains (CP27 and CP36) inhibited nitric oxide production significantly, in response to the positive control, i.e., taxol-treatment. Notably, CP27 and CP36 were more potent at reducing nitric oxide production than senloytic compounds (fisetin, quercetin). Using enzyme linked immunosorbent assays, the production of pro-inflammatory cytokines (IL-1β, TNF-α, PGE2), was markedly reduced by treatment with CP27 and CP36, in response to stress. Both CP27 and CP36 contain a plethora of metabolites to exact their effects [(3,4-dihydroxyphenylglycol, 5-methoxytryptophan, nifedipine, 4-chlorotestosterone-17-acetate, 3-phenoxypropionic acid, lactic acid, f-Honaucin A, l,l-Cyclo(leucylprolyl), 3-hydroxy-decanoic acid etc.], indicative of their potential in providing protection against cellular stress. Further high-throughput bioassay-guided testing of gut microbial metabolites from crocodiles, individually as well as in combination, together with the underlying molecular mechanisms, in vitro and in vivo will elucidate their value in the rational development of innovative therapies against cellular stress/gut dysbiosis.

Space medicine: gut microbiome of hardy species is a potential source to counter disorders during space travel

It is proposed that gut microbiome of species like cockroaches may offer a potential source of novel mechanisms/molecules that can be translated into humans to safeguard astronauts against stressors of the space environment during deep space exploration missions.

Mass spectrometric analysis of bioactive conditioned media of bacteria isolated from reptilian gut

Aim

To determine whether selected gut bacteria of crocodile exhibit antibacterial properties.

Materials & methods

Two bacteria isolated from Crocodylus porosus gut were used, namely: Pseudomonas aeruginosa and Aeromonas dhakensis. Conditioned media were tested against pathogenic bacteria and metabolites were analyzed using liquid chromatography-mass spectrometry.

Results & conclusion

Antibacterial assays revealed that conditioned media showed potent effects against pathogenic Gram-positive and Gram-negative bacteria. LC-MS revealed identity of 210 metabolites. The abundant metabolites were, N-Acetyl-L-tyrosine, Acetaminophen, Trans-Ferulic acid, N, N-Dimethylformamide, Pyrocatechol, Cyclohexanone, Diphenhydramine, Melatonin, Gamma-terpinene, Cysteamine, 3-phenoxypropionic acid, Indole-3-carbinol, Benzaldehyde, Benzocaine, 2-Aminobenzoic acid, 3-Methylindole. These findings suggest that crocodile gut bacteria are potential source of novel bioactive molecules that can be utilized as pre/post/antibiotics for the benefit of human health.

Microbiome and One Health: Potential of Novel Metabolites from the Gut Microbiome of Unique Species for Human Health

For thousands of years, the notion that human health and performance are concomitant with the health and diversity of the microbiome has been deliberated upon [...].

Improving the effectiveness of anti-aging modalities by using the constrained disorder principle-based management algorithms

Aging is a complex biological process with multifactorial nature underlined by genetic, environmental, and social factors. In the present paper, we review several mechanisms of aging and the pre-clinically and clinically studied anti-aging therapies. Variability characterizes biological processes from the genome to cellular organelles, biochemical processes, and whole organs' function. Aging is associated with alterations in the degrees of variability and complexity of systems. The constrained disorder principle defines living organisms based on their inherent disorder within arbitrary boundaries and defines aging as having a lower variability or moving outside the boundaries of variability. We focus on associations between variability and hallmarks of aging and discuss the roles of disorder and variability of systems in the pathogenesis of aging. The paper presents the concept of implementing the constrained disease principle-based second-generation artificial intelligence systems for improving anti-aging modalities. The platform uses constrained noise to enhance systems' efficiency and slow the aging process. Described is the potential use of second-generation artificial intelligence systems in patients with chronic disease and its implications for the aged population.

Effect of Microgravity on the Gut Microbiota Bacterial Composition in a Hindlimb Unloading Model

We utilised a ground-based microgravity hindlimb unloading (HU) mouse model to elucidate the gut microbiota bacterial changes in mice under a simulated microgravity environment. Four-month-old, male C57/Bl6 mice were randomly divided into ground-based controls and the HU groups and kept under controlled environmental conditions. For the microgravity environment, the mice were suspended in special cages individually for 20 days. At the end of the suspension, the mice were sacrificed; gut dissections were performed, followed by a metagenomic analysis of bacterial species, which was carried out by extracting DNA and 16S rRNA analysis. The results revealed that the gut bacterial communities of mice under gravity and microgravity were different. Notably, our findings revealed differences in the bacterial community structure. Around 449 bacterial OTUs were specific to mice kept under normal gravity versus 443 bacterial OTUs under microgravity conditions. In contrast, 694 bacterial OTUs were common to both groups. When the relative abundance of taxa was analyzed, Bacteroidetes dominated the gut (64.7%) of normal mice. Conversely, mice in the microgravity environment were dominated by Firmicutes (42.7%), and the relative abundance of Bacteroidetes differed significantly between the two groups (p < 0.05). The distribution of Muribaculaceae between normal mice versus microgravity mice was significantly different, at 62% and 36.4%, respectively (p < 0.05). Furthermore, a significant decrease in 11 bacteria was observed in mice under simulated microgravity, including Akkermansia muciniphila, Eubacterium coprostanoligenes, Bacteroides acidifaciens, Clostridium leptum, Methylorubrum extorquens, Comamonas testosterone, Desulfovibrio fairfieldensis, Bacteroides coprocola, Aerococcus urinaeequi, Helicobacter hepaticus, and Burkholderiales. Further studies are needed to elucidate gut bacterial metabolites of these identified bacterial species in microgravity conditions and normal environment. Notably, the influence of these metabolites on obesity, neuroprotection, musculoskeletal and cardiovascular dysfunction, longevity, inflammation, health, and disease in astronauts ought to be investigated and will be important in developing procedures against adverse effects in astronauts following space travel.

The Use of Gut Microbial Modulation Strategies as Interventional Strategies for Ageing

Gut microbial composition codevelops with the host from birth and is influenced by several factors, including drug use, radiation, psychological stress, dietary changes and physical stress. Importantly, gut microbial dysbiosis has been clearly associated with several diseases, including cancer, rheumatoid arthritis and Clostridium difficile-associated diarrhoea, and is known to affect human health and performance. Herein, we discuss that a shift in the gut microbiota with age and reversal of age-related modulation of the gut microbiota could be a major contributor to the incidence of numerous age-related diseases or overall human performance. In addition, it is suggested that the gut microbiome of long-lived animals such as reptiles should be investigated for their unique properties and contribution to the potent defense system of these species could be extrapolated for the benefit of human health. A range of techniques can be used to modulate the gut microbiota to have higher abundance of “beneficial” microbes that have been linked with health and longevity.

Novel Sources of Bioactive Molecules: Gut Microbiome of Species Routinely Exposed to Microorganisms

Simple Summary

The majority of antibiotics available in the market are produced by bacteria isolated from soil. However, the low-hanging fruit has been picked; hence, there is a need to mine bacteria from unusual sources. With this in mind, it is important to note that animals and pests, such as cockroaches, snake, crocodiles, water monitor lizards, etc., come across pathogenic bacteria regularly, yet flourish in contaminated environments. These species must have developed methods to defend themselves against pathogens. Besides the immunity they may confer, bacteria associated with animals/pests may offer a potential source of novel antibacterial agents. This paper discusses the current knowledge of bacteria isolated from land and marine animals with antibacterial properties and proposes untapped sources for the isolation of bacteria to mine potentially novel antibiotic molecules.

Abstract

The development of novel bioactive molecules is urgently needed, especially with increasing fatalities occurring due to infections by bacteria and escalating numbers of multiple-drug-resistant bacteria. Several lines of evidence show that the gut microbiome of cockroaches, snakes, crocodiles, water monitor lizards, and other species may possess molecules that are bioactive. As these animals are routinely exposed to a variety of microorganisms in their natural environments, it is likely that they have developed methods to counter these microbes, which may be a contributing factor in their persistence on the planet for millions of years. In addition to the immune system, the gut microbiota of a host may thwart colonization of the gastro-intestine by pathogenic and/or foreign microorganisms through two mechanisms: (i) production of molecules with antibacterial potential targeting foreign microorganisms, or (ii) production of molecules that trigger host immunity targeting foreign microorganisms that penetrate the host. Herein, we discuss and deliberate on the current literature examining antibacterial activities that stem from the gut bacteria of animals such as crocodiles, cockroaches, and water monitor lizards, amongst other interesting species, which likely encounter a plethora of microorganisms in their natural environments. The overall aim is to unveil a potential library of novel bioactive molecules for the benefit of human health and for utilization against infectious diseases.