The transformation of steroids by microorganisms is widely used in medical biotechnology. A huge group of filamentous fungi is one of the most promising taxa for screening new biocatalytic reactions in order to obtain pharmaceutically significant steroids. In this work, we screened 10 filamentous fungi-destructors of egg tempera for the ability to biotransform androst-4-en-3,17-dione (AD) during cultivation in a liquid nutrient medium or in a buffer solution. These taxonomically unrelated strains, belonging to the classes Eurotiomycetes, Dothideomycetes and Sordariomycetes, are dominant representatives of the microbiome from halls where works of tempera painting are stored in the State Tretyakov Gallery (STG, Moscow, Russia). Since the binder of tempera paints, egg yolk, contains about 2% cholesterol, these degrading fungi appear to be a promising group for screening for steroid converting activity. It turned out that all the studied fungi-destructors are able to transform AD. Some strains showed transformation efficiency close to the industrial strain Curvularia lunata RNCIM F-981. In total, 33 steroids formed during the transformation of AD were characterized, for 19 of them the structure was established by gas chromatography/mass spectrometry analysis. In this work, we have shown for the first time that fungi-destructors of tempera paintings can efficiently transform steroids.

Inflammatory bowel diseases are extremely common throughout the world. However, in most cases, it is asymptomatic at the initial stage. Therefore, it is important to develop non-invasive diagnostic methods that allow identification of the IBD risks in a timely manner. It is well known that gastrointestinal microbiota secrete volatile compounds (VOCs) and their composition may change in IBD. We propose a non-invasive method to identify the dynamics of IBD development in the acute and remission stage at the level of VOCs in model of dextran sulfate sodium (DSS) with chemically induced colitis measured by headspace GC/MS (HS GC/MS). Methods: VOCs profile was identified using a headspace GC/MS (HS GC/MS). GC/MS data were processed using MetaboAnalyst 5.0 and GraphPad Prism 8.0.1 software. The disease activity index (DAI) and histological method were used to assess intestinal inflammation. The peak of intestinal inflammation activity was reached on day 7, according to the disease activity index. Histological examination data showed changes in the intestine due to different stages of inflammation. As the acute inflammation stage was reached, the metabolomic profile also underwent changes, especially at the short-fatty acids level. A higher relative amounts of acetic acid (p value < 0.025) and lower relative amounts of propanoic acid (p value < 0.0005), butanoic acid (p value < 0.005) and phenol 4-methyl- (p value = 0.053) were observed in DSS7 group on day 7 compared to the control group. In remission stage, disease activity indexes decreased, and the histological picture also improved. But metabolome changes continued despite the withdrawal of the DSS examination. A lower relative amounts of propanoic acid (p value < 0.025), butanoic acid (p value < 0.0005), pentanoic acid (p value < 0.0005), and a significant de-crease of hexanoic acid (p value < 0.0005) relative amounts were observed in the DSS14 group compared to the control group on day 14. A model of DSS-induced colitis in rats was successfully implemented for metabolomic assessment of different stages of inflammation. We demonstrated that the ratios of volatile compounds change in response to DSS before the appearance of standard signs of inflammation, determined by DAI and histological examination. Changes in the volatile metabolome persisted even after visual intestine repair and it confirms the high sensitivity of the microbiota to the damaging effects of DSS. The use of HS GC/MS may be an important addition to existing methods for assessing inflammation at early stages.

Obesity and associated metabolic diseases are often accompanied by changes in the gut microbiota leading to metagenome gene diversity decrease. Fecal microbiota transplantation (FMT) is one of the most effective methods for correcting the intestinal microflora. FMT obtained from healthy donors has been proven to be an effective treatment of infections caused by Clostridium difficile. The use of FMT for correction of metabolic disorders is promising, however, data on its application is limited and has contradictory results. In our work, two patients (siblings) presented with obesity grade II and various types of diabetes mellitus (DM): the older brother (44 years old) with diabetes mellitus type 2 (DM 2), a younger brother (39 years old) with diabetes mellitus type 1 (DM 1). Both patients underwent FMT as part of complex antidiabetic therapy. During the course of treatment, a decrease in body weight was noted in both patients (4–5 kg for the first month of observation, then -1–2 kg per month). One year after FMT, a patient with type 2 diabetes showed a decrease in the severity of insulin resistance (IR), measured by the hyperinsulinemic euglycemic clamp test (initial M-index 2.42 mg/kg*min, after 1 year — 3.83 mg/kg* min) as well as the maintenance of satisfactory carbohydrate metabolism compensation against the diminishing the hypoglycemic therapy. In a patient with DM 1, no significant dynamics of carbohydrate exchange indices, including detected glycated hemoglobin (HbA1c), insulin dose and IR were during the observation period. Metagenomic sequencing of stool samples (n = 20) collected from both patients before and within 1 year after FMT showed no significant changes in the taxonomic profile of the microbiota at the level of microbial families. Metabolomic analysis of the composition of feces showed no directed changes in the composition of metabolites after the FMT procedure, the nature of changes within the samples from each patient during the entire study period was random. Thus, FMT had no effect on the course of DM1, but served as a starting point for weight loss and improvement glucose profile in DM2. However, convincing data confirming a causal correlation between FMT and improvement in the course of T2DM have not been obtained.

The genus Parabacteroides comprises widespread gastrointestinal commensals, known to produce immunomodulatory molecules and extracellular vesicles, yet its full diversity is incompletely cataloged. This study describes strain ASD2025^T, isolated from healthy child feces, using a polyphasic taxonomic approach including phenotypic profiling, chemotaxonomy, and comparative genomics. Cells were non-motile, polymorphic rods that produced extracellular vesicles. Phylogenomic analysis placed ASD2025^T within the genus Parabacteroides within a species complex consisting of P. acidifaciens, P. hominis, “P. massiliensis”, P. merdae, and P. johnsonii, with average nucleotide identities to the type strains of 85.5–89.9%. The large genome (5.16 Mbp, 46.2% GC content) contained integrative conjugative elements harboring antibiotic resistance genes and hankyphage-related prophage. The strain produced succinate as the major metabolic end product, and its major fatty acids were anteiso-C_15:0, iso-C_17:0 3-OH, and C_15:0. Conditioned medium from ASD2025^T antagonized the interleukin-8 response caused by E. coli lipopolysaccharide in HT29 cells. The majority of related metagenome-assembled genomes originate from mouse microbiomes. Based on these distinct characteristics, strain ASD2025^T (=VKM B-3926^T = JCM 37967^T) represents a novel species of the genus Parabacteroides, for which the name Parabacteroides vesiculifaciens sp. nov. is proposed.