Animal studies show increased inflammation in the gut and a change in gut microbiota composition due to emulsifiers and additives in our food. Our intestine is protected from gut bacteria by the thick layer of mucus that lines it. The mucus stops the bacteria from reaching the intestine's inner lining and causing inflammation. Unfortunately, emulsifiers can destroy this intestinal mucus layer, leaving the wall unprotected from the microbiotas that reside there. Thus, bacteria can start causing inflammation in the gut wall. Epidemiological, cellular and animal studies have shown links between emulsifier consumption and inflammatory bowel disease, especially Crohn's disease.
More specifically, when two dietary emulsifiers, namely, polysorbate-80 and carboxymethyl cellulose, were given to mice (along with their regular diet) in doses that were well within the limits that humans consume, they brought about obesity, intestinal inflammation, and problems with metabolism. What was even more interesting was that adding these emulsifiers to mice with no microbiota (germ-free mice) did not bring about any of the consequences. In contrast, when microbiota was transferred from the emulsifier-treated mice to the germ-free mice, they induced the observed effects of obesity, inflammation and metabolic issues.
There is limited evidence directly linking emulsifiers and thickeners to human disease, but multiple potential pathogenic mechanisms exist. Knowledge of actual dietary intake and high-quality interventional studies are needed to clarify the risks associated with their intake.
It should also be noted that excess fat, refined grains, sugar and artificial sweeteners negatively influence our gut microbiota. High fructose corn syrup (HFCS) has been associated with fatty liver and the presence of inflammatory bacterial toxins.
What is the Bt Toxin? Is it Safe in Genetically Modified Foods?
Bt toxins are a group of proteins naturally produced by the bacterium Bacillus thuringiensis. This bacterium is a gut pathogen for many organisms. The bacterium produces these toxins, which, through a sequence of events, become activated and kill the organism by forming holes in the membranes of the organism's gut lining.
Bt is used in agricultural sprays to destroy pests. This has been shown to pose no health risk because it degrades very quickly in daylight and thus does not end up being eaten by people.
Genetically modified (GM) organisms that express Bt toxins, such as cotton, corn and soybeans, are also commercially made. Through genetic modification, these organisms contain the genes that allow them to produce Bt toxin, making them resistant to pests. The problem is that evidence shows that the Bt toxins produced in these genetically modified crops are vastly different from the naturally occurring ones. Naturally occurring Bt proteins are large, insoluble, nontoxic molecules requiring specific chemical conditions to become active toxins. In the case of GMOs, however, the Bt proteins are very similar in structure to the toxic active molecules and do not require many steps and conditions to become actively harmful.
When animals and people ingest these crops, the Bt protein is also ingested, and studies have shown the Bt protein from GM foods to be present in human blood. It has also been detected in fetal blood, suggesting that it probably can be passed from the mother to the next generation.
Currently, the impact of the toxicity of Bt toxins and the impact on the gut microbiome upon consumption of such toxins from genetically modified crops is unknown, and more research is necessary to clarify this phenomenon.
These findings highlight the importance of the consumption of whole instead of processed foods.
References
Latham JR, Love M, Hilbeck A. (2017) The distinct properties of natural and GM cry insecticidal proteins. Biotechnology and Genetic Engineering Reviews; 33:1.
Dolezel, M., et al. (2011). Scrutinizing the current practice of the environmental risk assessment of GM maize applications for cultivation in the EU. Environmental Sciences Europe; 23, 33.
https://www.gmwatch.org/en/news/latest-news/17888-gmo-bt-toxins-safe-for-people-and-environment-or-supertoxins
Then C, Bauer-Panskus A. (2017) Possible health impacts of Bt toxins and residues from spraying with complementary herbicides in genetically engineered soybeans and risk assessment as performed by the European Food Safety Authority EFSA. Environ Sci Eur; 29(1):1.
WGO Practice Guideline - Diet and the Gut (English) 2018
http://www.worldgastroenterology.org/guidelines/global-guidelines/diet-and-the-gut/diet-and-the-gut-english