In recent years, more and more data indicate the effect of human microbiota on carcinogenesis. Despite the numerous studies on the relationship between gut microbiota and carcinogenesis, the exact mechanisms of this interaction are not well studied. It becomes apparent that this relationship can be mediated by microbial metabolites. Mechanisms of some well-known bacterial genotoxins and oncogenes, such as colibactin, CagA, IpgD, VirA, P37, have been studied in detail. At the same time, a role in carcinogenesis of a large group of gut microbial metabolites, including short-chain fatty acids, polyamines, and products of polyphenol and tryptophan catabolism, is less well understood. However, more and more evidence data show the effect of bacterial metabolites on cancer development and progression. In this review, we summarize relevant data regarding the possible mechanisms that can account for the effects of gut microbial metabolites mentioned above in carcinogenesis.

Biofilms are the reason for a vast majority of chronic inflammation cases and most acute inflammation. The treatment of biofilms still is a complicated task due to the low efficiency of drug delivery and high resistivity of the involved bacteria to harmful factors. Here we describe a magnetically controlled nanocomposite with a stimuli-responsive release profile based on calcium carbonate and magnetite with an encapsulated antibiotic (ciprofloxacin) that can be used to solve this problem. The material magnetic properties allowed targeted delivery, accumulation, and penetration of the composite in the biofilm, as well as the rapid triggered release of the entrapped antibiotic. Under the influence of an RF magnetic field with a frequency of 210 kHz, the composite underwent a phase transition from vaterite into calcite and promoted the release of ciprofloxacin. The effectiveness of the composite was tested against formed biofilms of E. coli and S. aureus and showed a 71% reduction in E. coli biofilm biomass and an 85% reduction in S. aureus biofilms. The efficiency of the composite with entrapped ciprofloxacin was higher than for the free antibiotic in the same concentration, up to 72%. The developed composite is a promising material for the treatment of biofilm-associated inflammations.

Colanic acid (CA) is an exopolysaccharide found in Enterobacteriaceae. Recently, its ability to stimulate physical activity in mice and to prolong the lifespan of invertebrates has been described. In the current work, we use standard MTT assay, fluorescence microscopy, and flow cytometry to describe CA action on several cell lines of different origins. We observed slight antiproliferative activity against colorectal cancer (HCT-116), neuroblastoma (IMR-32), and myoblast (C2C12) cell lines at a concentration of 256 μg/mL, while other cell lines of non-cancerous origin (Vero, HPF) did not show any decrease in the MTT assay. In all cell lines, we observed a rearrangement of mitochondria localization using fluorescence microscopy. CA induces cell differentiation in the myoblast cell line (C2C12) at concentrations of 50–200 μg/mL. Briefly, we observed that the number of apoptotic cells increased and the metabolic activity in the MTT assay decreased, which was accompanied by changes in cell morphology, the quantity of ROS, and the potential of the mitochondrial membrane. Taken together, these results indicate that CA is specific in cytotoxicity to cell lines of different origins and can impact mitochondria and differentiation, consistent with its potential geroprotective function.

Background/Objectives: Gut dysbiosis has been implicated in multiple sclerosis (MS), but microbial signatures remain inconsistent across studies. Machine learning (ML) algorithms based on global microbiome data integration can reveal key disease-associated microbial biomarkers and new insights into MS pathogenesis. This study aimed to investigate gut microbial signatures associated with MS and to evaluate the potential of ML for diagnostic applications. Methods: Fecal samples from 29 relapsing–remitting MS patients during exacerbation and 27 healthy controls were analyzed using 16S rRNA gene sequencing. Differential abundance analysis was performed, and data were integrated with 29 published studies. Four ML models were developed to distinguish MS-associated microbiome profiles. Results: MS patients exhibited reduced levels of Eubacteriales (p = 0.037), Lachnospirales (p = 0.021), Oscillospiraceae (p = 0.013), Lachnospiraceae (p = 0.012), Parasutterella (p = 0.018), Faecalibacterium (p = 0.004), and higher abundance of Lachnospiraceae UCG-008 (p = 0.045) compared to healthy controls. The Light Gradient Boosting Machine classifier demonstrated the highest performance (accuracy: 0.88, AUC-ROC: 0.95) in distinguishing MS microbiome profiles from healthy controls. Conclusions: This study highlights specific microbiome dysbiosis in MS patients and supports the potential of ML for diagnostic applications. Further research is needed to elucidate the mechanistic role of these microbial alterations in MS progression and their therapeutic utility.

Objective: As capsule and biofilm matrix polysaccharide, colanic acid protects bacteria from environmental factors. Its synthesis is regulated by temperature, so it is not normally produced at a human body’s temperature. However, colanic acid causes pleiotropic phenotypic effects in nematodes, including a lifespan prolongation. Results and Discussion: The aim of the current work was to evaluate colanic acid activity in vitro and in vivo (on mice). We revealed that colanic acid does not cause cytotoxicity in colon cancer (HCT116), neuroblastoma (IMR-32), and fibroblasts (HPF) cell lines, but changes mitochondrial morphology by an induction of its fusion. However, in subchronic toxicity study on mice signs of a general toxicity appeared. At the same time, mice had increased physical and sexual activity, which indicates the stimulatory effect of the polysaccharide. In exhaustive swimming test mice showed an increased time of swimming, which provides evidence of both effect on mitochondria and increased performance in aerobic exercise. Conclusions: The followed decline of an endurance may be associated with both toxic effects and metabolism shift. Following these findings, colanic acid can be considered as a bioactive polysaccharide with a wide spectrum of a potential applications.

This research focuses on the Pseudanabaena genus Antarctic strains, in particular on their ability to grow at low temperature, as well as on their phylogenetic relatedness with other cyanobacteria. Pseudanabaena sp. strains CALU 1773, CALU 1785, CALU 1787 and CALU 1791 were cultured at various temperatures. Culture growth was monitored via cell suspension optical density, and biomass was measured by cell dry weight; additionally, a morphometric analysis was performed. Based on the obtained data, it was concluded that Antarctic Pseudanabaena strains represent psychrotolerant objects (they are able to grow at 20°С although their growth optimum is ˂15°С). At suboptimal temperatures (4°С and 22°С), cells get deformed. Analysis of 16S rRNA sequences of studied strains together with those from GenBank demonstrated a high genetic variability within the genus Pseudanabaena. The studied Antarctic strains formed branch which is distinct from the Arctic psychotolerant strain of Pseudanabaena catenata USMAC16. The obtained data indicate that adaptation to low temperatures could occur in representatives of the genus Pseudanabaena more than once.