Adherent-invasive Escherichia coli (AIEC) has been implicated as a microbiological factor in the pathogenesis of inflammatory bowel disease (IBD). We evaluated the ability of six live biotherapeutic products (LBPs) to inhibit the interaction of an AIEC strain to three cell lines representing human gut epithelium. Co-inoculation of LBPs with AIEC showed a reduction in adhesion (up to 73%) and invasion of AIEC (up to 89%). Pre-inoculation of LBPs in HT-29-MTX and Caco-2 cells before challenging with AIEC further reduced the adhesion and invasion of the AIEC, with three LBPs showing significantly (p < 0.0001) higher efficiency in reducing the adhesion of AIEC. In co-inoculation experiments, the highest reduction in adhesion (73%) of AIEC was observed in HT-29-MTX cells, whereas the highest reduction in invasion (89%) was seen in HT-29-MTX and the co-culture of cells. Pre-inoculation of LBPs further reduced the invasion of AIEC with highest reduction (97%) observed in co-culture of cells. Our results indicated that whilst there were differences in the efficacy of LBPs, they all reduced interaction of AIEC with cell lines representing gut epithelium. Their efficiency was higher when they were pre-inoculated onto the cells, suggesting their potential as candidates for alleviating pathogenesis of AIEC in patients with IBD.

Candida albicans is a semi-ubiquitous pathobiont that is known to significantly impact human health and wellbeing, causing a significant financial strain on the medical system. Due to increasing antifungal resistance, there is a growing need for novel fungal therapeutics to treat diseases caused by this fungus. The development and use of Live Biotherapeutic Products (LBPs) is an innovative and novel approach to potentially treating Candidiasis and other comorbidities associated with C. albicans infection. To evaluate their anti-pathogenic efficacy, it is necessary to understand the underlying mechanisms involved, via the use of biomimetic cell models. In this study, six LBPs were chosen to investigate their competitive inhibitory effect against C. albicans using a co-culture of Caco-2 cells and mucous-secreting HT29-MTX cells to mimic human gut epithelium. The LBP strains were supplied by Servatus Biopharmaceuticals and identified as SVT 01D1, SVT 04P1, SVT 05P2, SVT 06B1, SVT 07R1 and SVT 08Z1. Five out of the six LBPs showed a significant reduction in the adhesion of C. albicans and all six LBPs reduced C. albicans invasion in the co-culture cells to varying degrees. There was no significant difference between co-inoculation of C. albicans with the LBPs or pre-inoculation of LBPs before the addition of C. albicans. The potential of these LBPs as novel anti-fungal therapeutics for the treatment of C. albicans diseases can be further documented in clinical trials.