Intestinal MMC-related electric fields and pancreatic juice control the adhesion of Gram-positive and Gram-negative bacteria to the gut epithelium--in vitro study.

Abstract

The adhesion of six different Lactobacillus and Lactococcus and three pathogenic Escherichia and Salmonella strains was studied using Caco-2 cell line. In this in vitro model system the influence of weak electric field (EF) on bacterial adhesion was tested. The EF source was the in vitro reconstruction of spiking potentials recorded in the duodenum of a healthy calf during one myoelectrical migration complex (MMC) cycle. The ability to adhere to Caco-2 cells of bacteria belonging to two groups, Gram-positive lactobacilli and lactococci, and Gram-negative Escherichia and Salmonella differed considerably. The pathogenic bacteria adhered better to well-differentiated Caco-2 cells whereas lactobacilli and lactococci displayed better adhesion to non-differentiated Caco-2 cells. In the presence of MMC-related EF an increased adhesion of Lactobacillus and Lactococcus but not of Salmonella enterica s. Enteritidis and E. coli 269 to Caco-2 cells was observed. Two later strains adhered even less in the presence of EF. The same tendency was found in the presence of pancreatic juice in a cell medium. In conclusion, the myoelectric component of the small intestinal motility, the MMC-related EF, and pancreatic juice may increase the ability of lactic acid bacteria to adhere to GI epithelial cells, creating better environmental conditions for colonization of the intestine and competition with Gram-negative pathogens.

AI evidence extraction

Main findings

Using a Caco-2 cell model, MMC-related weak electric fields increased adhesion of Lactobacillus and Lactococcus strains, while Salmonella enterica s. Enteritidis and E. coli 269 did not show increased adhesion and were reported to adhere less in the presence of the electric field. A similar tendency was observed when pancreatic juice was added to the medium.

Outcomes measured

• Bacterial adhesion to gut epithelium (Caco-2 cells)
• Differential adhesion by bacterial group/strain (Gram-positive vs Gram-negative)
• Effect of MMC-related electric field on adhesion
• Effect of pancreatic juice on adhesion

Limitations

• In vitro Caco-2 cell line model; may not generalize to in vivo gut conditions
• Exposure parameters (e.g., field strength, waveform details beyond being an MMC reconstruction) not specified in the abstract
• Sample size/number of replicates not reported in the abstract

{
    "study_type": "in_vitro",
    "exposure": {
        "band": null,
        "source": "intestinal myoelectric (MMC-related) weak electric field (in vitro reconstruction of duodenal spiking potentials)",
        "frequency_mhz": null,
        "sar_wkg": null,
        "duration": "one MMC cycle (reconstructed spiking potentials)"
    },
    "population": null,
    "sample_size": null,
    "outcomes": [
        "Bacterial adhesion to gut epithelium (Caco-2 cells)",
        "Differential adhesion by bacterial group/strain (Gram-positive vs Gram-negative)",
        "Effect of MMC-related electric field on adhesion",
        "Effect of pancreatic juice on adhesion"
    ],
    "main_findings": "Using a Caco-2 cell model, MMC-related weak electric fields increased adhesion of Lactobacillus and Lactococcus strains, while Salmonella enterica s. Enteritidis and E. coli 269 did not show increased adhesion and were reported to adhere less in the presence of the electric field. A similar tendency was observed when pancreatic juice was added to the medium.",
    "effect_direction": "mixed",
    "limitations": [
        "In vitro Caco-2 cell line model; may not generalize to in vivo gut conditions",
        "Exposure parameters (e.g., field strength, waveform details beyond being an MMC reconstruction) not specified in the abstract",
        "Sample size/number of replicates not reported in the abstract"
    ],
    "evidence_strength": "low",
    "confidence": 0.7399999999999999911182158029987476766109466552734375,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "electric field",
        "myoelectrical migration complex",
        "MMC",
        "duodenum",
        "Caco-2",
        "bacterial adhesion",
        "Lactobacillus",
        "Lactococcus",
        "Escherichia coli",
        "Salmonella",
        "pancreatic juice",
        "gut epithelium"
    ],
    "suggested_hubs": []
}

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