1. Intermittent fasting (typically defined as going 12 to 18 hours a day without food) positively impacts the gut microbiome and protects against central nervous system (CNS) autoimmunity. A recent study in mice found that IF increases gut bacteria richness and diversity (resulting in an increase in Lactobacillaceae, Bacteroidaceae, and Prevotellaceae families), and positively alters gut microbiome composition and antioxidative metabolic pathways. When the gut microbiome from IF mice was transferred to mice who were immunized with a multiple sclerosis (MS) model, the MS mice were protected. Cell Metabolism
→Takeaway: IF has shown in this study and in others to positively impact the gut microbiome, and therefore, could be a viable everyday practice to help improve microbial balance. Intermittent energy restriction (IEF – eating 500 calories per day 1 to 2 days out of the week) was proven in recent studies to help ameliorate MS in human subjects and may be an avenue to explore for those looking to improve microbial health or protect against/treat central nervous system autoimmunity.
2. Common stool processing techniques (such as freeze thawing or blending in oxygen) for fecal microbiota transplantation (FMT) may significantly reduce efficacy of the procedure. Using a process called PMA, which differentiates between dead and live bacteria and discards the DNA data for dead bacteria, scientists found that even when using the best stool processing protocols available, approximately 50 to 80% of the bacteria in FMT stool samples were destroyed. Unfortunately the types of bacteria most negatively affected are commensal obligate anaerobes, which have strong anti-inflammatory properties. These types of bacteria produce a metabolite called butyrate that plays a key role in reducing inflammation in the body. Even when using best stool processing practices, the ability of the transplanted bacteria to produce butyrate was very low and was nearly zero when the stool was processed in oxygen. Healio
→Takeaway: These findings tell us that current stool processing techniques have significant negative impacts on transplanted bacteria used in FMT and may deem FMT useless for inflammatory-related diseases and conditions such as inflammatory bowel disease (Crohn’s and ulcerative colitis).
3. If you’re currently on a ketogenic diet (keto) or considering one for weight loss or to improve overall health, there are important things to consider. Creating the right environment to reach ketosis varies across individuals and without working with a doctor or nutritionist it’s nearly impossible to know if you’re in ketosis. In addition, to properly follow the diet you must consume 80 to 90% of calories from fat and strictly limit carbohydrates (10 to 15 grams of daily – equivalent to about ½ a banana) and protein (the body will break down protein, if available, to get its glucose for energy). With such a high fat content, many individuals consume unhealthy fats to allow for variety in the diet instead of sticking to healthy unsaturated fats like avocado. An unvaried diet (or the scary alternate of high consumption of unhealthy fats) isn’t the only risk – keto can lead to more serious health concerns such as bone demineralization, increased cardiovascular disease risks, and negative impacts on the gut microbiome. Lastly, while you may lose weight on keto initially, most dieters gain their weight back. Popular Science
→Takeaway: If you’re looking for a dietary intervention to lose weight or improve overall health, focus on one based on consuming a wide variety of plant foods, that places food quality above caloric content, and that promotes the growth of beneficial gut bacteria (high in indigestible plant fiber!). If you’re looking for a jump-start, check out Dr. Chutkan’s plans in Gutbliss and The Microbiome Solution.
4. Scientists studied the sex-based differences in the intestinal barrier function and gut microbiome of 23 volunteers administered indomethacin (NSAID most commonly prescribed for rheumatoid arthritis and gout). At baseline, healthy women showed lower intestinal permeability and higher microbial diversity than healthy men. While indomethacin increased intestinal permeability in both sexes, only women experienced decreased diversity in fecal bacteria. While the microbiome and intestinal permeability returned to baseline 4 to 6 weeks after NSAID administration in both males and females, researchers conclude that women have a lower intestinal permeability, higher microbial diversity, and a less stable microbiome than men. Federation of American Societies for Experimental Biology
→Takeaway: While this study looked at only 23 participants and touts some profound conclusions, it’s interesting to consider gender-based differences in the gut microbiome – and if any differences actually exist. In 2015, uBiome, one of the first companies to collect microbial data from the general population, found that based on their gut database, no statistically significant differences exist between the composition of the male and female gut microbiome. Yet many studies have concluded that sex-based differences in gut microbial composition do indeed exist (some of the differences are due to the fact that the same diet affects the male and female microbiome differently) and these differences could be the determining factor in why so many more women than men suffer from autoimmune disease.
By: Leslie Ann Berg, MSPH