Intestinal Microbes and Heart Disease

     The significance of the study I will discuss is not completely clear other than to show that the microbes in one's digestive tract can have quite an impact on health. It should be pointed out before I discuss this bit of reasearch that the Mayo Clinic reviewed 13 controlled trials involving 3, 629 patients and found that L-carnitine reduced all-cause mortality by 27%, reduced ventricular arrhythmias by 65%, reduced angina by 40% and reduced infarct size.
     A recent study found that feeding mice acetyl carnitine as 1.3% of the diet resulted in alteration of the bacteria in the digestive tract of the animals. These bacteria converted the L-carnitine into TMAO (trimethylamine-N-oxide). The L-carnitine was not a problem unless the bacteria were present. Diets high in red meat tend to produce increased populations of these bacteria compared to diets containing other meats or vegetarian diets. TMAO was shown to cause or accelerate the development of heart disease in mice. The researchers found little evidence that cholesterol was a causative factor in heart disease.
     Scientists are focusing increasing attention on what is called the microbiome, the population of bacteria which inhabit the digestive tract. It appears that these bacteria can create all kinds of health problems. Healthy bacterial populations in the digestive tract are promoted by fiber intake and by supplementing with acidophilus and other beneficial organisms. Vegetarians did not produce TMAO when they consumed red meat suggesting that it takes consistent consumption of red meat to promote the growth of the bacteria which contribute to TMAO accumulation in the body.
     This study suggests that cholesterol is not a primary reason why red meat intake increases the risk of heart disease. Heart disease may be more closely associated with bacterial populations in the digestive tract.
     Koeth, Robert A., et al., Intestinal microbiota metabolism of L-carnitine, a nutrient in red meat, promotes atherosclerosis, Nature Medicine, April 7, 2013; doi:10.1038/nm.3145
DiNicolantonio, James J., et al., L-Carnitine in the secondary prevention of cardiovascular disease systematic review and meta-analysis, Mayo Clinic Proceedings, June 2013; 88(6),  DOI: http://dx.doi.org/10.1016/j.mayocp.2013.02.007
http://www.elsevier.com/about/press-releases/research-and-journals/l-carnitine-significantly-improves-patient-outcomes-following-heart-attack

Autism and Nutrition

     Modification of the diet and supplementation of the diet of autistic individuals carries little risk and offers considerable benefit. A diet free of gluten and dairy resulted in improvement of 69% of those who tried th diet. Over half of those wth the condition improve on a diet free of sugar and food additives. Food allergy treatment resulted in improvement of 67% of the patient population. A wide range of nutrients tried individually resulted in improvement in one-third to one-half of autistic children. Nutrients tested included vitamin A, folic acid, vitamins B6, B12, vitamin C, calcium, mangnesium, and zinc. High dose vitami B6 with magnesium is often beneficial. Omega-3 fatty acids improved 59% of the children it was given to. Digestive enzymes improved almost two-thirds of children. A diet free of disaccharides (this includes grains) which promote growth of potentilly harmful bacteria in the digestive tract improved 71% of patients. These nutritional approaches did not have a worsening effect in most instances.

Research Report on Autism

     Dr. James Adams, a professor at Arizona State University and co-chair of Autism Research Institute's Scientific Advisoy Committee, has published a comprehensive review paper on dietary, nutritional, and medical treatments for autism. The review is based on 150 published references.
Link to review paper on autism.

Autism and the Gut

     It has been known or a long time that people with autism tend to have intestinal problems. These digestive problems are associted with unbalanced populations of microbes in the lower digestive tract. The population of bacteria in the digestive tract is known as the microbiome.
Those with autism are prone to overgrowth of a species of bacteria called Clostridia. Clostridia produce toxic compounds called phenols which kill other bacteria which compete with them for space in the digestive tract.
     Phenols are poisonous to human cells unless they can be neutralized by sulfur. Overgrowth of Clostridia can deplete the body's reserves of sulfur which is also essential for brain development. Many autistic individuals evidence a defect in sulfur metabolism which could increase susceptibility to damage from the toxins prodced by Clostridia. Research is ongoing to see if abnormal sulfur metabolism and Clostridia overgrowth may play a role in the abnormal brain development characteristic of autism.
Reference:
Me, myself, us, The Economist, Augst 18, 2012, 69-72.