Expert reveals surprising link between kissing your partner and a healthier gut

Dr Naomi Middleton, a clinical psychologist specialising in gut health, has revealed the hidden benefits of living with your partner, explaining that healthy ecosystems become intertwined. She highlighted that everything from kissing, sharing meals and living spaces, and physical closeness play a significant role in supporting a balanced gut microbiome and overall digestive health.

She added that just being in someone else’s presence for a prolonged period can promote microbial diversity and reduce stress-related gut inflammation. It comes after research of 2,000 adults found that of those who live with their partner, 40% have noticed a greater sense of companionship since moving in together. While other benefits cited include improved mood for 28% and 19% even sleep better.

Dr Middleton, who partnered with Yakult, said: “The people you live with don’t just share your space – they share your microbes, your rhythms and even your gut health.

“The gut microbiota is highly responsive to shared environments and close social bonds, particularly with those we spend significant amounts of time with.

“This increased diversity from close contact could also help reduce stress-related gut inflammation, offering further long-term health benefits.”

Dr Middleton added that kissing can play a significant role in supporting a balanced gut microbiome and overall digestive health.  According to the study, people in relationships share an average of five kisses a day, with each lasting around eight seconds.

Loved-up Welsh couples were revealed to be the most affectionate overall, averaging 42 kisses a week, while Londoners linger the longest – with each smooch lasting an average of 15 seconds, with married couples clocking up 1,460 kisses a year.

The clinical psychologist said a single 10-second kiss can transfer up to 80 million bacteria between partners. However, this isn’t a bad thing, as it helps create a shared oral microbiome, which may influence gut ecosystems and support immune resilience. 

In addition, regular affectionate contact can help regulate stress responses. “In that sense, kissing supports both emotional wellbeing and physical health in ways many people wouldn’t expect,” she adds.

Along with kissing, she also encourages couples to share more meals together, as this helps synchronise digestive patterns and supports a healthy metabolism.

Dr Holly Neill, Yakult’s science manager, said: “Close contact is a vital part of healthy relationships, helping couples feel emotionally connected, supported and reassured.

“While the emotional benefits of affection are well known, there’s growing evidence that physical closeness can also support physical health in less obvious ways.

“Sharing daily moments of affection can help reduce stress, support wellbeing and even influence the balance of bacteria we carry.

“It’s a powerful reminder that small, everyday gestures can have a meaningful impact on both relationship satisfaction and overall health.”