It is that time of year again! Time to start planning those back to school lunches. As the year wears on, it is an easy option to reach for those prepared lunch box foods. But this can cause leaky gut in your little one!
Our Microbiome Says Skip the Processed Foods
Prepared, processed foods offer such convenience but most processed foods offer little in the way of nutrition compared to the abundance of sugar, unhealthy fats, chemicals and additives they contain. Processed food have been linked to obesity, metabolic syndrome, cancer, heart disease and autism/neurological behavioral changes. New research is highlighting how our gut bacteria don’t like processed food either.
The gut microbiome relies on the fiber in our diet to ferment into butyrate for fuel. A recent study showed that a two week change in diet has a notable impact on the gut microbiome. Researchers compared African-Americans eating a standard American diet to South Africans eating a traditional diet. The traditional diet was much higher in fiber while the Western diet was higher in industrial fats, refined carbohydrates, and animal proteins like those found in processed foods.
Researchers gave the Africans a Western diet for two weeks, and the African-Americans a traditional African diet for two weeks. The gut microbiome changed dramatically in this short time. The healthy gut microbes that make butyrate increased 2.5 fold in the Americans on the African diet, whereas butyrate levels dropped by 50% when the Africans switched to the Western diet. Researchers also found greatly increased markers of intestinal inflammation after the two week Western diet while the inflammatory markers in the American guts dropped after two weeks on a traditional diet. (1) Our microbiome is intimately tied to the food we eat and processed food is not only empty nutrition but it actually changes the balance of beneficial bacteria in the gut.
The Additives in Processed Foods Can Cause Leaky Gut
A diet high in processed foods exposes the gut bacteria to an array of chemicals, additives, fillers, binders, emulsifiers and more that irritate the gut lining. This irritation can lead to leaky gut or intestinal permeability. Tight junctions hold the bases of the cells that line the gut together making the lining impermeable so that food cannot enter the bloodstream. They do a great job when they are functioning properly but they can also lose integrity and become permeable when exposed to inflammatory conditions. The inflammatory cytokines that are released in response to irritation promote the loss of integrity of the tight junctions and promote the intestinal permeability in leaky gut. Research has shown how the chemical emulsifiers in processed food changes the diversity of the gut microbiome for the worse. Emulsifiers in food have been shown to promote bacterial translocation across epithelial cells. Now they have been shown to increase the inflammatory state of the gut. (2)
Researchers fed mice two very commonly used emulsifiers, polysorbate 80 and carboxymethylcellulsose, comparable to amounts found in processed foods. They found that mice that consumed the emulsifier had changes pro-inflammatory changes in the gut microbiota. The pro-inflammatory microbiota had an enhanced capacity to infiltrate the dense mucus layer that lines the intestine, which is normally harbors few bacteria. (2) The mucin layer houses the gut microbiome and acts as a barrier to the lining of the gut. Disturbances in the mucin layer affects the balance of beneficial bacteria and makes it easier for the gut to get inflamed and leaky.
What Should We Put in Our Children’s Lunches?
Pre-prepared, processed foods have already been associated with several chronic diseases and, combined with this new research highlighting the impact processed food has on the gut microbiome and gastrointestinal tract, it becomes clear that we need to make an effort to limit processed foods for our children. A varied diet packed full of whole foods or processed foods with minimal ingredients is the best foundation for a healthy gut microbiome. Some easy ways to get those whole foods into lunches include hummus or nut butters with veggies and crackers, sandwiches of all kinds and bento lunches like the ones we’ll be featuring for the next few weeks on this blog. I can often recruit help from my little ones to gather the ingredients, do the cutting and assemble the lunches. They really enjoy it and it helps foster a healthy relationship to food and food prep. My three year old and almost seven year old often eat more of their packed lunches when they help make them too. With a little planning, packing healthy lunches that help nourish the body and the microbiome are a simple step to help create a solid foundation of health. Comment below with your favorite lunches to pack!
– Dr. Catherine Clinton
(1) O’Keefe, S. J. D. et al. Fat, fiber and cancer risk in African Americans and rural Africans. Nat. Commun. 6:6342 doi: 10.1038/ncomms7342 (2015).