Review – 9/6/18

1. Do you struggle to lose weight? Your microbiome could have something to do with it. A recent study implemented a 3-month lifestyle intervention in 26 overweight and obese adults (aged 18 to 65) and compared weight loss success (defined as losing 5% or more of baseline body weight) with microbial composition. Results showed an association between weight loss success and an increased abundance in Phascolarctobacterium, while weight loss failure (unable to lose 5% of body weight in the 3-month period) was associated with an increased abundance of Dialister and a gut microbiome that is genetically efficient in metabolizing carbohydrates. Mayo Clinic Proceedings

→Takeaway: Microbial health plays a key role in our ability to reach and maintain a healthy weight. If you struggle with weight loss, focusing on balancing your microbiome (or rewilding!) could be an important first step. For a comprehensive plan to optimize microbial health in your everyday life, check out Dr. Robynne Chutkan’s book The Microbiome Solution.

2. Early life antibiotic exposure shows no association with autism spectrum disorder (ASD). A recent study including all live births in Manitoba, Canada between 1998 and 2016 looked at antibiotic exposure (defined as having filled one or more antibiotic prescriptions in the first year of life) and ASD diagnosis. The study found that antibiotic exposure (both number of treatment courses and cumulative duration of antibiotic exposure) was not associated with ASD, and researchers concluded that the lack of a significant association between antibiotics and ASD “should provide reassurance to concerned prescribers and parents”. International Journal of Epidemiology

→Takeaway: While this study aims to answer the question, is exposure to antibiotics in the first year of life a risk factor for developing ASD, it fails to take into account some important factors. First, while the researchers looked at the number of antibiotic prescriptions filled in the first year of life, we all know that a filled prescription does not mean the patient actually took the medication. Second, antibiotic exposure often begins well before birth – in the womb and during the birthing process. Past studies have found a strong association between ASD and antibiotic exposure in early life as well as exposure in the womb. Lastly, ASD is associated with increased GI symptoms and imbalanced gut bacteria (which are worsened by antibiotics). While we don’t know whether an altered microbiome is a result of ASD, or its cause, it’s best to avoid antibiotic exposure before, during, and after birth.

3. Could your gut bacteria make you smarter (or not so smart)? Recent studies show overwhelming evidence that the microbial communities living within our gut play a central role in brain function and development, behavior, and even cognition, including learning and memory. A recent paper outlines how advances in microbial research can be utilized to understand individual variations in cognition. Philosophical Transactions of the Royal Society B: Biological Sciences

→Takeaway: Cognition begins in the gut! If you are looking to have an intellectual edge and optimize your brainpower, grow a good gut garden. If you feel like your memory, learning, and overall cognitive sharpness is becoming foggy or dull, rewilding could be your answer. Where can you start? Dr. Chutkan recommends consuming lots of leafy greens and indigestible plant fiber daily. Try a daily green smoothie to fertilize your gut garden and “wake up” your brain!

4. Want to slow down the aging process, live longer, feel younger? Eat less. Partial results from the most comprehensive study on calorie restriction (a 2-year randomized controlled trial including 200+ healthy adults looking at the effects of calorie restriction on metabolism) in humans and its effect on slowing the aging process have just been released. Tests assessing overall metabolism and biological markers for aging were performed in 53 participants between ages 21 and 50. 34 of the participants reduced their calorie intake by 15%, while 19 ate as usual. Results showed that those on the reduced calorie regimen used energy much more efficiently while sleeping (even when weight loss was taken into account) and experienced a reduced metabolic rate and a significant decrease in damage due to aging. Cell Metabolism

→Takeaway: Reduced calorie diets in animals show incredible benefits in slowing aging and extending life. Calorie restriction in mice has shown to extend life span up to 65% longer! This study confirms that some of the benefits observed in animal studies can be applied to humans. Researchers conclude that a long-term reduced calorie diet could prolong health in old age and possibly extend life in humans. Therefore, eating less could be an important lifestyle practice in living a healthier, longer life. But how much less is the question? Benefits are observed by eating approximately 15% less calories than your daily allowance.

By: Leslie Ann Berg, MSPH