Galacto-oligosaccharides exert a protective effect against heat stress in a Caco-2 cell model

• GOS prevent the heat-induced up-regulation of HSPs on mRNA and protein level.
• GOS reduce the heat-induced stress response in Caco-2 cells.
• GOS protect the heat-induced disruption of the intestinal epithelial barrier.

Thermal stress can evoke a stress response and enhance the synthesis of heat shock proteins, while gut barrier dysfunction is considered as an important adverse effect of thermal stress. Considering the previously described effects of galacto-oligosaccharides, nowadays mainly used in infant formulas, we hypothesized that galacto-oligosaccharides may protect the intestinal barrier against heat stress. Human epithelial colorectal adenocarcinoma cells were pre-treated with galacto-oligosaccharides prior to thermal stress exposure (40–42 °C) for 24 h. Pre-treatment of galacto-oligosaccharides prevented the heat stress-induced up-regulation of heat shock proteins and reduced the heat-induced stress response as observed by a decrease in haem oxygenase-1. Galacto-oligosaccharides partly prevented the heat-induced effects on monolayer integrity as measured by transepithelial electrical resistance, paracellular permeability and E-cadherin expression. In addition to their prebiotic effect, galacto-oligosaccharides may have beneficial potency to protect the intestinal epithelial barrier against heat stress and may be an attractive dietary application for people who are at high risk of developing heat stress.