Melanie Camoin grew up eating baguettes in France.
In traditional French fashion it was a staple food in her household but when she moved to New Zealand in 2011, all that changed.
The Waihi resident found herself feeling bloated, having a sore stomach, bowel issues, mood swings and becoming lethargic.
"It's just terrible. I feel so s*** and so tired. I had to sleep 12 hours a day and had no energy at all."
Three months later she cut out bread and wheat products like pizza, pasta and pastries and the symptoms stopped.
"I actually was poisoning myself."
But when she goes home or travels to other parts of Europe, or even the United States, she can dig in to all the gluten-filled food she can't usually eat and feels fine. She can even make her own food using T55 flour imported from France with no problem.
And she's not alone.
So why can many non-Coeliac gluten-sensitive Kiwis eat wheat-based foods overseas without experiencing the gut-wrenching pain they feel at home?
Principal scientist at Plant and Food Research Nigel Larsen is trying to answer just that question.
"It is an issue which seems to be real but we don't know why," he said. "So far it's a mystery to us as to why we hear stories like that because that's one of the things that prompted us to start doing research on the issue.
"There's all sorts of things that could be different. It could be the wheat varieties, it could be the way we grow our wheat, it could be the way we process our wheat – who knows. It's just something we don't understand and we're trying to get to the bottom of."
Plant and Food Research have teamed up with the Baking Industry Association of New Zealand to fund research into where the differences could be and why wheat seemed to have such a huge affect on many Kiwis.
Larsen had already looked into the way dough was mixed in New Zealand but did not find an answer there.
He had started studying proteins called amylase-trypsin inhibitors which were present in wheat. Their function in grains was to stop insects from eating them and there had been research suggesting they may cause inflammation. But, there was nothing to indicate the levels in New Zealand were any higher than overseas, he said.
Larsen was also looking into the proteins that aggravated Coeliac disease and how they could breed new wheat varieties with lower levels as well as which sourdoughs lowered the gluten levels of bread.
The yeast and bacteria in a sourdough starter worked together to digest the gluten proteins meaning the gut did not have to work as hard to get rid of them.
But not all sourdoughs are the same, Larsen found. While he was hesitant to divulge which types were better than others, he did reveal San Francisco sourdough was better for those intolerant to gluten.
Similar to sourdoughs, the rising process in bread could also play a part, but that would not explain the difference when eating pastas and pastries, Baking Industry Association of New Zealand president Kevin Gilbert said.
When bread rises, a fermentation process is taking place where enzymes begin to break down and convert proteins like gluten. The longer bread is fermented for, the more the proteins are broken down and the easier it becomes for the gut to process.
In the 60s, a new process of bread making was developed called chorelywood. It allowed bakers to go from flour to a loaf of bread bagged in about three hours. The traditional style of bread-making involved anywhere from three to 60 hours of fermenting alone, Gilbert said.
That was part of the reason many artisan breads, which were more common in Europe, were easier to stomach than loaves of sliced bread from the supermarket, he said.
While all wheat contained the same proteins, different grades of flour were used in Europe and had a different protein ratio whereas New Zealand flour usually only came in one grade.
Traditional Italian pasta was also usually made from durum flour rather than wheat flour, he said.
Professor of Nutrition at the Liggins Institute David Cameron-Smith agreed some types of flour had less gluten and when those low-gluten flours were used to make bread in the traditional style they had less impact on those sensitive to gluten.
He believed part of the problem was that we had become reliant on high gluten strains of wheat that allowed bread to rise and become soft in a very short period of time.
But, it was possible gluten was not the issue at all for many people.
Paediatric gastroenterologist at Otago University in Christchurch and Christchurch Hospital, Professor Andrew Day said it could be the sugars from carbohydrates which were the problem, and Larsen agreed.
Cereals like wheat all contained sugars, such as fructose, but some strains contained more than others, Day said.
Overseas studies had shown that many people who reacted badly to cereals were reacting to the sugars rather than the gluten, he said.
"If those sugars can not all be absorbed in the small bowel they get through to the large bowel and get fermented which contributes to gas production leading to bloating, diarrhoea, belly pain and so on," he explained.
He believed the most likely answer to the mystery was that strains of wheat with higher amounts of sugar triggered symptoms in people whose bodies did not absorb the sugar as well.
But, for now, those like Camoin will have to rely on a process of trial and error to work out what they can and can't eat.
What is gluten?
• A general name for the proteins found in wheat, rye, barley and triticale.
• Gluten helps foods maintain their shape, acting as a glue that holds food together.
• Gliadin is the protein in wheat which coeliacs react to.
• It is estimated about 1 in 70 New Zealanders have Coeliac disease but many more people believe they are intolerant to gluten (non-Coeliac gluten sensitivity).