When we first think of bacteria, we may usually think about the harmful strands and the infections they cause. However, what if I said that some bacteria are actually helpful? In fact, we have over a thousand different species of bacteria in our gut which serve a vital role in ensuring our well being¹. For instance, Lactobacillus reuteri (L. reuteri) is a common bacteria that protects our gut from harmful pathogenic microorganisms, aids in lactose digestion, produces vitamins, and contains several anti-inflammatory properties². If L. reuteri alone plays these roles in maintaining our wellbeing, just imagine the effect of a thousand different bacterial species acting in our gut! However, to see these health benefits, we have to sustain our gut microbiota – something that is becoming increasingly difficult in a society where ultra-processed foods (UPFs) are consumed daily. But what exactly are UPFs and how do they hinder our gut microbiota?
Ultra-processed foods (UPFs) are foods that have been heavily refined, infused with various additives, and contain high amounts of fats, sugars, and salts³. As delicious as these foods may be, they are lacking in essential nutrients and fiber, and constant consumption has negative effects on our well being tied to disruptions to gut microbiota³. Our gut bacteria are highly dependent on the diet we sustain. A healthy diet means our gut bacteria are supplied with essential nutrients to keep them thriving; however, UPFs lack the necessary nutrients to help our microbiota grow⁴. As mentioned before, these foods are high in additives and fat, which means our gut bacteria are not being properly nourished. As a result, there is a reduction in microbiota diversity.
With a decrease in essential gut bacteria, our intestines are more susceptible to harmful pathogens and inflammation⁵. Studies have shown that excess consumption of UPFs have led to several health disorders, among which includes Inflammatory Bowel Disease (IBD), anxiety and depression³. Additionally, excess consumption of UPFs and their high fat content have been linked to a number of brain disorders³. This is because the hippocampus, a region of the brain responsible for memory and learning, is vulnerable to excess saturated fat, and damage to the hippocampus can result in decreased cognitive function and neuroinflammation⁶. On the other hand, the high added sugar content in UPFs can accumulate as fat in our tissues and lead to disorders such as obesity and non-alcoholic fatty liver disease⁶.
Ultra-processed foods, gut microbiota, and overall human wellbeing are all linked together. Our gut bacteria is essential in protecting our body from harmful pathogens and supplies our body with essential nutrients, but the overconsumption of UPFs kills these bacteria and leads to health complications. In order to ensure we take care of our bodies, it is important to be kind to our gut and cognizant of the food we consume.
References
1. Zhang YJ, Li S, Gan RY, Zhou T, Xu DP, Li HB. Impacts of Gut Bacteria on Human Health and Diseases. Int J Mol Sci. 2015;16(4):7493-7519. doi:10.3390/ijms16047493
2. Mu Q, Tavella VJ, Luo XM. Role of Lactobacillus reuteri in Human Health and Diseases. Front Microbiol. 2018;9:757. doi:10.3389/fmicb.2018.00757
3. Song Z, Song R, Liu Y, Wu Z, Zhang X. Effects of ultra-processed foods on the microbiota-gut-brain axis: The bread-and-butter issue.
4. Shi Z. Gut Microbiota: An Important Link between Western Diet and Chronic Diseases. Nutrients. 2019;11(10):2287. doi:10.3390/nu11102287
5. Cuevas-Sierra A, Milagro FI, Aranaz P, Martínez JA, Riezu-Boj JI. Gut Microbiota Differences According to Ultra-Processed Food Consumption in a Spanish Population. Nutrients. 2021;13(8):2710. doi:10.3390/nu13082710
6. Martínez Leo EE, Segura Campos MR. Effect of ultra-processed diet on gut microbiota and thus its role in neurodegenerative diseases. Nutrition. 2020;71:110609. doi:10.1016/j.nut.2019.110609