{
  "abstract": "Background A substantial proportion of the anaerobic microbiota is comprised of bacteria belonging to the genus Bacteroides. It is well established that species within this genus possess immunomodulatory properties, which may be beneficial in the treatment of inflammatory bowel disease (IBD). However, not all representatives of Bacteroides demonstrate the capacity to attenuate inflammatory responses. Accordingly, the objective of this study was to identify the most immunologically active Bacteroides strains with potential application as probiotic candidates for the management of inflammatory bowel diseases.Methods In this study, the secretomes of selected Bacteroides (n=18) and Phocaeicola(n=4) strains were examined following cultivation in nutrient-depleted medium. These secretomes were subsequently applied to the HT-29 cell line to assess the expression of TLR2 and TLR4 genes, as well as the secretion of interleukin-8 (IL-8). In addition, headspace gas chromatography–mass spectrometry (HS GC–MS) was employed to profile volatile bacterial metabolites that may contribute to immunomodulatory effects.Results The findings indicated that the examined bacterial strains exerted heterogeneous effects on host receptors, leading to either upregulation or downregulation of receptor gene expression and interleukin-8 secretion under basal conditions as well as following stimulation with E. coli O55:B5 lipopolysaccharide (LPS). Metabolomic profiling revealed a broad spectrum of bacterial metabolites, including short- and medium-chain fatty acids, phenolic compounds, and aldehydes. Integrating metabolite data with cellular response patterns enabled the classification of the studied strains into three functional categories: anti-inflammatory strains (Bacteroides uniformis, Bacteroides stercoris, Bacteroides intestinalis, Bacteroides clarus), pro-inflammatory strains (Bacteroides thetaiotaomicron, Bacteroides caccae, and Bacteroides eggerthii ), and strains exhibiting mixed immunomodulatory effects, whose activity appeared to be strongly dependent on their metabolomic profiles.Conclusions These results indicate that the combined assessment of secreted metabolites and receptor-mediated cellular responses is critical for elucidating the immunomodulatory capacity of gut bacteria and may facilitate the informed selection of promising probiotic candidates.This publication was carried out with state funding for the «IBD-ONCO 25-27» project, state registration number of R&D 125030703327-1",
  "authors": [
    {
      "affiliations": [
        "Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Russia"
      ],
      "name": "Natalya Zakharzhevskaya"
    },
    {
      "affiliations": [
        "Peoples’ Friendship University of Russia named after Patrice Lumumba, Russia"
      ],
      "name": "Irina Podoprigora"
    },
    {
      "affiliations": [
        "Pirogov Russian National Research Medical University, Ostrovityanova str, Moscow, Russia"
      ],
      "name": "Andrei Chaplin"
    },
    {
      "affiliations": [
        "Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Russia"
      ],
      "name": "Dmitry Kardonsky"
    },
    {
      "affiliations": [
        "Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Russia"
      ],
      "name": "Elizaveta Vorobyeva"
    },
    {
      "affiliations": [
        "Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Russia"
      ],
      "name": "Daria Kashatnikova"
    },
    {
      "affiliations": [
        "Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Russia"
      ],
      "name": "Victoriia Kazakova"
    },
    {
      "affiliations": [
        "Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Russia"
      ],
      "name": "Irina Kolesnikova"
    },
    {
      "affiliations": [
        "Lopukhin Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Russia"
      ],
      "name": "Boris Efimov"
    }
  ],
  "title": "IDDF2026-ABS-0427 The immunomodulatory potential of the bacteroides secretome: a search for novel probiotics",
  "uid": "2beb6eab-0998-5aab-9f38-9b6602d03746"
}