Unraveling the Impact of Ultra-Processed Foods: A Journey into the Gut Microbiome
In our quest to understand the effects of ultra-processed foods on our health, researchers are calling for innovative research methods. The spotlight is on our gut microbiota, and the insights it holds.
Wilhelm Glomm, a researcher at SINTEF's Department of Biotechnology and Nanomedicine, is intrigued by the potential impact of ultra-processed food on our intestinal flora. While studies on this topic abound, Glomm argues that many simplify the problems or methods for investigating these effects.
Take, for instance, the common method of investigating additives like emulsifiers. Researchers have replaced laboratory animals' drinking water with a 1% emulsifier solution. Glomm points out the fallacy of this approach, comparing it to concluding that the salt in eyewash, a simple solution of salt and water, is harmful to the eyes.
But what exactly constitutes ultra-processed food? These are foods produced using one or more refining processes, often with additives to change consistency, increase shelf life, or restore color. However, defining ultra-processed food is a challenge, as there is no universal agreement on the most suitable classification system.
The NOVA system, the most well-known classification, defines ultra-processed food based on criteria such as ingredients mostly used by the industry, raw materials that have been broken down and reconstituted, and added sugar, fat, and salt.
Glomm believes that studying the digestive system and the gut can provide valuable insights into the effects of ultra-processed food. "What happens in the gut is crucial. It houses more than two-thirds of the body's immune system, and our diet significantly impacts our gut microbiota, which includes bacteria, viruses, and fungi. This complex system reflects the state of our body and changes over time and age."
Glomm and his team conducted a clinical study on gut health, searching for the "ultra-processed culprits." They collected stool samples from volunteer women, men, and an infant, analyzing the composition of gut bacteria and the metabolites they produced. The study examined the relationship between gut bacteria, age, gender, and diet.
The method revealed a clear connection between specific gut bacteria and the metabolites they produce, which can be linked to the diet of the test subjects. Glomm explains, "We observed that certain gut bacteria caused the production of tryptamine, a 'good' metabolite that helps regulate weight and has anti-inflammatory properties."
The data showed significant variations in tryptamine production in the intestines of different individuals. Tryptamine can be traced back to ruminococcus, a type of bacteria that converts the amino acid tryptophan, found abundantly in protein sources like meat, eggs, fish, and dairy, into tryptamine. People who consumed these protein sources had sufficient levels of this beneficial tryptamine, while vegetarians had less.
Emulsifiers, a common additive in ultra-processed foods, have been linked to health challenges like obesity and intestinal inflammation. Glomm explains that emulsifiers are used to improve the miscibility of oil and water, which usually separate quickly when mixed. Adding an emulsifier ensures a fine distribution of oil droplets in the mixture.
The researchers studied a selection of widely used emulsifiers in different concentrations, with and without oil, observing the reaction of intestinal cells. They found that an emulsifier solution in water caused severe damage to intestinal cells, dissolving the cell layer and, in some cases, killing the cells. However, when oil was present, no damage was observed.
The team then examined the effect of emulsifiers on a mixture of good and bad intestinal bacteria. They added emulsifiers with water and oil and monitored the changes in intestinal bacteria composition over time. The results were similar to those with intestinal cells: the impact was minimal when oil was present.
While more research is needed to determine the health effects of emulsifiers, Glomm's study provides valuable insights into the connections between food and various health challenges, including intestinal inflammation, obesity, and diabetes.
This research highlights the importance of understanding the complex relationship between our diet, gut microbiota, and overall health. As we continue to unravel these connections, we move closer to making informed choices about our dietary habits and their impact on our well-being.
