A Prospective Study of Gluten Transfer Through Kissing in Celiac-Discordant Couples

Current management of celiac disease (CeD) depends on a restrictive gluten-free diet (GFD). Studies have reported CeD patients' anxiety about gluten transfer via kissing, but data to support this concern are lacking.

To assess the transfer of gluten through kissing, the non-CeD partner consumed a gluten load (10 crackers with 59,107 ppm or 590 mg gluten). In 2 protocols, after consuming the gluten load, the non-CeD partner kissed the partner with CeD. In the first kissing protocol, the non-CeD partner waited 5 minutes before kissing, and in the second, the non-CeD partner drank 4 oz of water and then immediately kissed the partner with CeD. Saliva was collected from the partner with CeD immediately after the kiss. Gluten in saliva was assessed by R-5 enzyme-linked immunosorbent assay test method and in the urine by GlutenDetect (Glutenostics, Inc).

Gluten was detectable in the saliva of the non-CeD partner in all protocols (80 ppm to >25,000 ppm). The amount detected in the saliva of those with CeD varied from <5 ppm to 153.9 ppm. Only 2 of the 20 gluten exposures tested >20 ppm gluten, the level defined as gluten free. None of the saliva samples tested >20 ppm when the non-CeD partner drank 4 oz of water after eating the gluten load.

There was not an increased risk of significant gluten transfer when kissing. Drinking 4 oz of water before kissing further reduces the risk. These results should guide our clinical practice and should be shared with our patients to help reduce the burden of the diet.