The dowside of ketogenic dieting
As much as I have been raving about the ketogenic diet for brain health and inflammation, I did want to bring to your attention that in the context of intestinal permeability, a high fat diet, particularly with saturated fat can contribute to endotoxemia. The endotoxins can contribute to low grade inflammation as your body works hard to try and remove these toxins. This is one of the downsides of a ketogenic diet. Metabolic endotoxemia begins with gram-negative bacteria residing in the gut, that have LPS (endotoxins) in their cell wall. The diet can play a significant role in whether you have circulating levels of endotoxins. Studies show that a diet high in saturated fat can contribute to more of these toxic metabolites. In fact, a study by Cani et. al demonstrated that a high fat diet in as little as 4 weeks long can chronically increase plasma LPS concentration 2-3 times. Importantly, a high-fat diet increased the proportion of an LPS-containing microbiota in the gut (Cani et al., 2007). This can dysregulate the “inflammatory tone”, and can contribute to hyperglycemia, hyperinsulinemia, and whole body, liver and adipose tissue weight gain. The more endotoxins create more inflammation, more inflammation and insulin resistance, and immune dysregulation (High Intensity Health, 2017). LPS can bind to receptors of many cell types, but particularly has an affinity for monocytes, dendritic cells, macrophages and B cells (Fulop, 2018). “Lipopolysaccharide triggers secretion of pro-inflammatory cytokines, generates superoxides, and acts as a pyrogen, causing fever” (Fulop, 2018). The generation of LPS by the gut biome is now considered an important factor in many inflammatory diseases, such as autoimmunity, allergy, metabolic syndrome, obesity, diabetes, AD, etc. In fact, the sudden postprandial increase in discomfort or illness people feel after eating may be caused by LPS generation in gut bacteria, a clue on intestinal permeability.
These studies were done on mice who consumed 72% of their diet from fat. Most of the literature points to a typical western diet that is high in fat and low in fiber, and macronutrient ratios are typically 40% fat, 40% carbs and 20% protein. Consuming a Western diet led to a 71% increase in the level of endotoxins in the blood, and the changes occur quickly. “One study found that within just one day of switching from a low-fat, plant-based diet to a high-fat, high-sugar diet reflecting the Western diet led to changes in the microbiome in humanized mice (germ-free mice colonized with adult human fecal microbiota) (Minich, 2017). An interesting video by Dr. Wood briefly discusses the high fat diet and endotoxemia, which can be tricky in the context of ketogenic dieting. Also, the video interview with David Asprey was interesting when he told his story of his full ketogenic diet and how it contributed to intestinal permeability, malaise and new food allergies.
The problem is not the fat per se, but the type of fat. In 2013, Mani et al demonstrated that meals rich in saturated fat such as coconut oil can increase postprandial endotoxin level concentrations, while meals high in omega-3 PUFA fish oil lowered endotoxins. According to a few studies I read, oils rich in DHA and EPA (fish oil, cod liver oil, algae oil) can attenuate LPS transport, while oils higher in saturated fats (coconut oil, palm oil, animal fats) can increase transport. Interestingly, canola oil and sunflower oil, although containing a high unsaturated fatty acid content, augmented plasma endotoxemia by 50-75%. A majority of these studies show that consuming high saturated fat diet for a longer period results in higher gram -negative bacterial populations and high fiber diets results in gram positive bacterial populations. “Furthermore, even though the mechanism is not clear, high intake of fat has been shown to cause internalization of tight junction proteins and increase in the paracellular permeability to macro molecules including endotoxin” (Mani et al., 2013).
I probably now sound wishy washy about the ketogenic diet. However, I think the best strategy is for each person to work with a functional nutritionist to find the diet that works best for them. It can be dangerous to dabble alone, as I tell many prospects, and sometimes aimless experimentation can cause more harm than good. It may be better to increase their consumption of polyunsaturated fats such as fish oil and monounsaturated fats such olive oil, and avoid foods that are too high in saturated fat, or fats that demonstrate increases in endotoxemia. Also, Brain McFarlin et al reported that supplementation with spore-based probiotics can lower postprandial endotoxemia reactions, by as much as 42% (McFarlin, Henning, Bowman, Gary, & Carbajal, 2017)!
Here is a spore based probiotic that I LOVE—>> https://naturalhealthachiever.com/blog/store/?model_number=Megaspore-Probiotic-
Cani, P. D., Amar, J., Iglesias, M. A., Poggi, M., Knauf, C., Bastelica, D., . . . Burcelin, R. (2007). Metabolic endotoxemia initiates obesity and insulin resistance. Diabetes, 56(7), 1761-1772. doi:10.2337/db06-1491
Fulop, J. (2018). High-Saturated Fat Increases Endotoxemia. Retrieved (2018, November 24) from https://www.naturalmedicinejournal.com/journal/2018-07/high-saturated-fat-diet-increases-endotoxemia
McFarlin, B. K., Henning, A. L., Bowman, E. M., Gary, M. A., & Carbajal, K. M. (2017). Oral spore-based probiotic supplementation was associated with reduced incidence of post-prandial dietary endotoxin, triglycerides, and disease risk biomarkers. World J Gastrointest Pathophysiol, 8(3), 117-126. doi:10.4291/wjgp.v8.i3.117
High Intensity Health (2017). Gut Health & Keto Diets- Endotoxemia and Bacterial Diversity w/ Tommy Wood, MD PhD. Retrieved (2018, November 24) from https://www.youtube.com/watch?v=_K2pmc4SKCU
Mani, V., Hollis, J. H., & Gabler, N. K. (2013). Dietary oil composition differentially modulates intestinal endotoxin transport and postprandial endotoxemia. Nutr Metab (Lond), 10(1), 6. doi:10.1186/1743-7075-10-6
Mani, V. (2012) Understanding intestinal lipopolysaccharide permeability and associated inflammation. Retreived (2018, July 18) from https://lib.dr.iastate.edu/etd/12788/
Minich, D. (2017). What you Need to Know about a High Fat Diet. Retrieved (2018, November 24) from https://www.huffingtonpost.com/entry/what-you-need-to-know-about-a-high-fat-diet_us_595f22c4e4b0cf3c8e8d57b0