Published Apr 11, 2026 | 7:50 AM ⚊ Updated Apr 11, 2026 | 7:50 AM
The study measured how much gluten transfers from one person to another through a kiss. (Representational pic/iStock)
Synopsis: A kiss is one of the most intimate things we do. But two new studies published in 2026 show that saliva carries more than just affection. It can transfer proteins that damage the gut, and viruses that may quietly rewire the immune system for years to come.
“Kiss me yet once again, the last, long
kiss, Until I draw your soul with my
Lips And drink down all your love.”
For starry-eyed lovers, Edith Hamilton’s words may sound romantic, a feeling that make them float like thistledown in the lightness of being in love.
Two recent studies, however, have raised a red flag, and suggested lovers kiss only after downing a glass of water.
The suggestion is unromantic — and a dreadful turnoff — especially when one asks the partner to drink water before puckering up for a smooch.
But for millions of people living with coeliac disease, the suggestion could soon become standard advice, backed by science for the first time.
The study published in the journal Gastroenterology is the first of its kind to actually measure how much gluten, the protein found in wheat, transfers from one person to another through a kiss.
When someone with coeliac disease eats gluten, their immune system treats it like an invader and attacks the lining of the small intestine. Over time, this causes real damage, affecting how the body absorbs nutrients. There is no medicine for it. The only treatment is to avoid gluten completely, for life. Even tiny amounts can cause harm.
Which is why a kiss, after a partner has eaten a wheat-based meal, feels like a genuine threat.
Researchers at Columbia University recruited 10 couples, each with one partner who had coeliac disease and one who did not. The non-coeliac partner ate 10 Saltine crackers, a wheat-based snack, and then kissed their partner.
In one round, they waited five minutes before kissing. In another, done on a separate day, they drank four ounces of water, roughly half a small glass, immediately before kissing. Saliva samples from the coeliac partner were then tested for gluten levels.
The findings were largely reassuring. In 90% of all samples, gluten levels were below 20 parts per million, the level considered safe for people with coeliac disease. Only two out of 20 kisses crossed that threshold, and even then, the actual amount of gluten that would have been swallowed was described by researchers as negligible.
The water step made an even bigger difference. When the non-coeliac partner drank water before kissing, not a single sample crossed the 20 parts per million (PPM) mark. In 60% of cases, no gluten was detected at all.
This matters more than it might seem. A previous study had found that 39% of people with coeliac disease felt hesitant to kiss their partners out of fear. Many had been following advice found online, including brushing teeth, carrying mouthwash, or asking their partner to eat only gluten-free food on dates. None of that advice was based on any scientific evidence.
“We can now inform patients about the quantitative risk of gluten exposure through kissing so that they can pursue relationships and intimacy without the fear of the unknown,” the researchers wrote.
A half glass of water. That is all it takes.
Now for the slower, quieter, and frankly more unsettling story.
You have probably experienced a bout of viral fever that brings extreme fatigue, a sore throat, and swollen glands in the neck. In many cases, this is caused by a virus called the Epstein-Barr virus, or EBV. It spreads through saliva, which is why the illness it causes, infectious mononucleosis, is nicknamed the kissing disease.
Most people recover within a few weeks and forget it ever happened.
But the virus never fully leaves the body. It goes dormant, hiding in immune cells, and most of the time causes no further trouble. Most of the time.
A study by researchers at the Mayo Clinic in the United States, published on 1 April 2026 in the journal Neurology, has found something that should make us pay closer attention to this very common virus.
People who had confirmed mono caused by EBV were more than three times as likely to develop multiple sclerosis later in life, compared to people who had never had mono.
Multiple sclerosis, or MS, is a condition where the immune system gets confused and starts attacking the protective covering around the body’s nerve fibres.
Think of it like the plastic insulation around an electrical wire being stripped away. Without that protection, signals between the brain and the rest of the body get disrupted. The result can be weakness, vision problems, difficulty walking, and fatigue. These symptoms tend to appear when people are in their thirties or forties, right in the middle of their most productive years.
The Mayo Clinic researchers analysed more than two decades of health records. They identified 4,721 people who had laboratory-confirmed EBV mono and compared them to over 14,000 people of the same age and sex who had not had mono. Both groups were tracked for an average of six to eight years.
Eight people in the mono group went on to develop MS, compared to 10 in the much larger control group. The numbers sound similar, but when accounting for the difference in group sizes and adjusting for other health factors like smoking and existing conditions, the risk was strikingly higher in the mono group.
“These results highlight the need for further research into ways to prevent infection with the Epstein-Barr virus,” said lead researcher Jennifer St. Sauver of the Mayo Clinic. “Preventing these infections could reduce the overall burden of MS.”
It is important to say that the study does not prove that mono causes MS. It shows a strong association, a pattern that keeps appearing across multiple studies now. The exact biological reason why EBV might trigger MS years later is still being studied.
But the signal is getting harder to ignore.
What connects these two different studies is something remarkably simple. Saliva.
One study shows that a kiss can transfer enough gluten to concern someone with coeliac disease, even if the actual risk is lower than most patients feared. The other shows that a virus travelling through saliva during adolescence may silently increase the risk of a serious neurological condition decades down the line.
One consequence plays out in the gut, within hours. The other plays out in the brain, across years.
Both involve the immune system turning against the body after encountering something that arrived through intimacy.
Neither study leaves us helpless.
For coeliac patients, the fix is almost surprisingly simple. A small glass of water before a kiss reduces gluten transfer to undetectable levels in most cases. That one finding has the potential to ease the anxiety of millions of people who have quietly been avoiding intimacy out of fear.
For the EBV and MS connection, the answer is more ambitious, but it is on its way. The Mayo Clinic study was partly funded by ModernaTX, the company behind one of the COVID-19 vaccines, which is now developing vaccines that target EBV. If those vaccines succeed, they could one day prevent the mono infections that may be quietly setting the stage for MS years later.
Science is learning, slowly but steadily, to interrupt the consequences that begin with something as ordinary as a kiss.
Hamilton may now have a second thought before crooning, “Kiss me yet once again…”, for the studies say the lover would be downing more than just love!
