Herbal extract fermented with inherent microbiota improves intestinal health by exerting antioxidant and anti-inflammatory effects in vitro and in vivo

Maintaining intestinal health is crucial for the overall well-being and productivity of livestock, as it impacts nutrient absorption, immune function, and disease resistance. Oxidative stress and inflammation are key threats to intestinal integrity. This study explored the antioxidant, anti-inflammatory, and barrier-strengthening properties of a fermented plant macerate (FPM) derived from 45 local herbs, using a specifically developed fermentation process utilizing the plants’ inherent microbiota to enhance bioactivity and sustainability. In vitro experiments with IPEC-J2 cells showed that FPM significantly reduced intracellular reactive oxygen species (ROS) levels, improved barrier integrity, and enhanced cell migration under stress. Similar antioxidant effects were observed in THP-1 macrophages, where FPM reduced ROS production and modulated inflammatory responses by decreasing pro-inflammatory cytokines [tumor necrosis factor alpha (TNF-α), monokine induced by gamma interferon (MIG), interferon-inducible T cell alpha chemoattractant (I-TAC), macrophage inflammatory proteins (MIP)-1α and -1β] and increasing anti-inflammatory interleukin (IL)-10 levels. Mechanistic studies with HEK-Blue reporter cell lines revealed that FPM inhibited nuclear factor kappa B (NF-κB) activation via a toll-like receptor (TLR)4-independent pathway. In vivo, FPM significantly reduced ROS levels in Drosophila melanogaster and improved activity and LT50 values in Caenorhabditis elegans under oxidative stress, although it did not affect intestinal barrier integrity in these models. The findings indicate that FPM shows promising application as a functional feed supplement for improving intestinal health in livestock by mitigating oxidative stress and inflammation. Further studies, including livestock feeding trials, are recommended to validate these results.