Photoprotective effects of galacto-oligosaccharide and/or Bifidobacterium longum supplementation against skin damage induced by ultraviolet irradiation in hairless mice

This study aimed at examining whether oral administration of galacto-oligosaccharide (GOS) and Bifidobacterium longum, individually or in combination, could exert photoprotective effects on the skin of hairless mice. GOS and/or Bifidobacterium were administered orally to hairless mice for 12 weeks. Mice were irradiated with UV light daily for four consecutive days. GOS administration increased the water-holDing capacity of the skin and prevented transepidermal water loss compared with the control. A reduction in the erythema formation of 16.8% was also observed in the GOS-treated group compared with the control, and CD44 gene expression was significantly increased. Oral administration of GOS or Bifidobacterium significantly increased TIMP-1 and Col1 mRNA expression compared with the control. Our findings support that prebiotics, incluDing GOS, are beneficial not only to the intestine, but also to the skin, and present the possibility of new nutritional strategies for the prevention of UV-induced skin damage.