Michael Lustgarten

About

Michael Lustgarten is Scientist II in the Nutrition, Exercise Physiology, and Sarcopenia (NEPS) Laboratory at the Jean Mayer Human Nutrition Research Center on Aging at Tuft's University. His research currently focuses on the role of the gut microbiome and serum metabolome on muscle mass and function in older adults. He is the author of the book Microbial Burden: A Major Cause Of Aging And Age-Related Disease.

Michael Lustgarten is also known for his rigorous n-of-1 health optimization experiments and quantified-self practice that he documents on his personal blog, michaellustgarten.com

Michael Lustgarten's Biohack Stack, Regimen, Routines

Interview

Hello! What’s your name, your background, and what do you do?

Michael Lustgarten. My PhD is in Physiology, and I’m currently a scientist at the Jean Mayer Human Nutrition Research Center on Aging at Tufts University.

How (and why) did you get involved in research in aging and the human microbiome? 

I had no idea what I wanted to do for about 4 years after graduating from college in 1994. That changed when I picked up Roy Walford’s book, “Beyond the 120 Year Diet”. Besides outlining the health benefits of calorie restriction, it also discussed using circulating biomarkers to track progress on the diet. I’d always been interested in optimal health and fitness, but reading that book took my interest to a higher level. I decided that would be my mission in life, to figure out how to live longer than 120 years, thereby breaking the world longevity record. To start to do that, I would need to go back to school, because my first university degree was in English literature. I then took all the science classes (Biochemistry major) that were required to go to graduate school to study aging, which took about 3 years. I worked my tail off, and got almost all A’s, to enhance my chances to get into a graduate school that I wanted to go to, rather than settling for a lower tier choice. The mitochondrial oxidative stress theory of aging was highly popular about 15 years ago, and one of the universities that had top scientists studying that were at the University of Texas Health Science Center at San Antonio. I applied there, got in, and started studying!

we co-evolved with microbes, and are ourselves half-microbial. Making sure we take care of them, and that they don’t end up in places where they shouldn’t be (blood, brain) is important for health, disease, and lifespan

My graduate work was performed exclusively in mice, and as a post-doc I wanted to study aging in people. As a grad student, I used a largely reductionist approach to study aging-we knocked out one gene and studied its effects on muscle mass and function in young and old mice. However, aging is multifactorial, and deficits in a single gene is unlikely to impact the full sum of aging (unless it’s a progeroid syndrome). I was interested in a more comprehensive approach for studying aging, and one way to do that is with metabolomics. My hypothesis was that by studying hundreds of biochemicals in blood, I’d get a more accurate picture about aging process in people. To do that, I joined a lab at Tufts that was interested in using a blood metabolomic approach for investigating mechanisms related to the maintenance of muscle mass and function in both young and older adult people. In the process of these analyses, I discovered associations for many gut bacterial metabolites with muscle. About 5 years ago, information on the gut microbiome-muscle axis was scant, so I wrote some grants to further explore that topic. Fortunately, I obtained grant funding, and I’ve been studying the gut-muscle axis ever since.

In your book, “Microbial Burden: A Major Cause of Aging And Age-Related Disease”, you make the case that optimizing our bodies to reduce microbial burden might delay age-related disease and extend life. Could you explain a little more about how microbes are connected to aging?

There’s little doubt about “might”. Germ-free mice are grown in a bubble for their entire life and live longer than mice that are conventionally raised (i.e. not in a bubble) that have a microbiome. That’s direct evidence for a role of the microbiome on affecting lifespan. However, humans didn’t evolve to live in bubbles, we co-evolved with microbes, and are ourselves half-microbial. Making sure we take care of them, and that they don’t end up in places where they shouldn’t be (blood, brain) is important for health, disease, and lifespan, as I demonstrate in the book. Ha, for more info, those interested can check out the book!

What are some of the biggest unanswered questions in your field of research? Optional: If you had 100 million dollars to conduct a single scientific trial, what trial would you conduct?

Beyond the gut, few studies have looked at the blood microbiome, or have only studied small components of it (i.e. LPS --Lipopolysaccharides ). Full microbiome sequencing, and not just bacteria, but viruses, fungi, archaea, and how that changes during aging would be on my list.

Also on the list would be investing in AI-based tools to integrate the human genome, diet, exercise intensity/duration, air quality, the microbiome, and blood metabolome to come up with a predictive algorithm that optimizes health while minimizing disease risk. Studies are starting to explore components of this (i.e. a personalized approach to the role of diet on blood glucose levels), but integrating all of these components will take a while.

I’d also invest in cell rejuvenation strategies, because even with the best lifestyle-based approach, aging still happens, albeit at a slower rate. We’ll need cell-based therapies, whether it’s stem cells or something else to help repair our aged cells, thereby rejuvenating them to a more youthful state.

I believe that my biochemistry and physiology training combined with my interest in nutrition, health, and fitness = the 21st century version of optimal health. Eventually, an AI-based approach will add to all that.

How did you get started in health optimization / quantified-self?

I’ve always been interested in nutrition, health, and fitness, but I took it to another level after reading Walford’s book. For many people, optimal health means eating real food and exercising, but without paying much attention to any of the details. For ex., that was Jack LaLanne’s mantra, and although he lived longer than average (he died at 95), that isn’t long enough for me. I believe that my biochemistry and physiology training combined with my interest in nutrition, health, and fitness = the 21^st century version of optimal health. Eventually, an AI-based approach will add to all that. Ha, hopefully I can add AI to further optimize my health to make it hard for the next generation to beat my approach (lol!).

What framework / philosophy do you use in evaluating and optimizing your body? How do you navigate the scientific literature to optimize your health?

I try to be as comprehensive as possible in my literature reviews for a given biomarker. For example, if I’m writing an albumin article and there are 500 abstracts related to albumin and aging, or albumin and mortality risk, etc., I’ll look at every single one of them, so by the time I’m done with that biomarker, I have a comprehensive understanding of what’s known. Then, I’ll write an article as succinctly as possible to summarize those findings. I’m not trying to bombard people into boredom with data, but I try to get to the point ASAP. Also, every few months I’ll do another literature search to potentially update any data that I’ve reported.

I try to keep it simple: How does the biomarker change with age, and with risk of death for all causes?. Most of the time, the range that is best for these 2 variables is smaller/different than the reference range. Once you know what’s optimal for these biomarkers, then the goal is to use nutrition, supplementation (if necessary), and fitness to obtain a biomarker profile that is as close to biologic youth as possible. So maybe you’re chronologically old, but your biomarkers look like a 20yr old.

For example, although I’m chronologically 46y,  my data for those 2 tests show than I’m 15-20 years biologically younger.

There are 2 key tools that I use to evaluate biologic youth: Levine’s Phenotypic age calculator, and aging.ai. They’re free, and are based on blood test data (which is not free). I have many articles on my blog about them and my data. For example, although I’m chronologically 46y,  my data for those 2 tests show than I’m 15-20 years biologically younger.

Some think that epigenetic testing is the gold standard for biological age testing, but consider this: its correlation with biological age has been reported to be 0.97 (a correlation = 1 is as good as it gets). For Levine’s phenotypic age calculator, it’s 0.94, almost as good, and 4x more affordable in terms of price, so I can test more often for relatively similar output data.

How do you approach tracking and optimizing your gut microbiome? What service do you use for gut microbiome testing now that uBiome is defunct? What are your thoughts on prebiotics, probiotics, and fermented foods?

So far, I’ve measured my gut microbiome composition 4x, and exclusively with uBiome. uBiome recently closed, so I’ll need to use a different company going forward, and likely I’ll use American Gut.

Early on with microbiome testing, I had almost no Bifidobacteria, and they’re important for producing short-chain fatty acids (SCFA), which strengthen gut barrier function. I took a lot of antibiotics as a kid, so that may have played a role in wiping them out. I tried various supplementation strategies to get them into my gut, but it took 3 separate trials to finally boost their levels. I have a blog post on my site about that. Nonetheless, the best way to optimize the gut microbiome is by eating lots of fiber, and from foods, not via supplements. Fiber is fermented by gut bacteria to directly produce SCFAs, which acidify the gut, thereby helping to minimize pathogenic bacterial growth (i.e. Enterobacteriaceae).

In terms of probiotics, I believe in quantifying your microbiome 1^st to see what’s missing, then supplementing with probiotics if you think that will help your health. Then, repeated microbiome testing to make sure that you’ve actually increased their abundance in the gut. Note that probiotics are seeds, so if you don’t eat what a certain bacterium likes (i.e. prebiotics), then they’ll die off/be passed out of the gut. So getting the right prebiotic for a given probiotic is also important. In terms of fermented foods, moderation is key. Evolutionarily, we ate foods that were fermented if we didn’t have anything else to eat (for ex., rotten apples). More recently, pickling was used to maintain the freshness of various foods without refrigeration. However, they weren’t the cornerstone of a varied diet, but a small component of it. Interestingly, I hadn’t included yogurt, which is fermented milk, in my diet for a long time, and my Lactobacillus were almost zero in my gut microbiome. In conjunction with that, my circulating levels of red blood cells hadn’t been higher than ~4.8, over the past 4 years but once I added the yogurt back into my diet, they suddenly they reached 5.1 on 2 different measurements. RBCs decline with age, so fighting off the age-related decrease is very important! Whether it was the bacteria, or something else in the yogurt, I don’t know, but it’s an interesting correlation nonetheless.

Nonetheless, the best way to optimize the gut microbiome is by eating lots of fiber, and from foods, not via supplements.

As a final note, it’s important to not solely focus on the microbiome. Is it of any use if the microbiome is improved but circulating biomarkers get worse? The key is to improve both, simultaneously. So for any gut microbiome testing, there should also be blood testing.

How can we optimize our skin and oral microbiomes?

I have sections on both in my book-for skin, it’s important to maintain its pH ~5. However, most soaps have a pH that is much higher than that, and even worse, pH isn’t generally listed on soap. Optimizing the mouth microbiome is more complicated, as there are far less studies on that when compared with the amount that study the gut microbiome. Nonetheless, I make a homemade mouthwash with sodium bicarbonate + xylitol. In contrast with an optimal skin ph around 5, a pH ~7 is optimal for the mouth. Some mouthwashes have a pH around 5, which is terrible when considering that caries accelerate at a pH < 5.

Which biometrics / biomarkers / vitals are you tracking and optimizing currently? (If comfortable sharing, what are your physical stats?) What are your target levels?

4-6x/yr I measure the analytes on the standard chemistry panel (i.e. albumin, glucose, lipids, liver enzymes, WBC and their differentials, etc.). In terms of what’s optimal for that, I have lots of blog posts for almost all of them on my website. It’s important to note that there is indeed a difference between the reference range and what may be optimal for health and longevity. Within that data, I’m able to calculate biological age using Levine’s Phenotypic Age calculator or with aging.ai. I’m interested in slowing aging, where my biological age doesn’t change as fast as my chronological age. For example, based on my blood test data over the past 4 years, my biological age metrics indicated that I had aged less than 2 years.

I also track my diet every day, including weighing all my food with a food scale, and entering that data into cronometer.com. Then, for each blood test, I calculate the average dietary intake that corresponds with it, and because I have data for more than 20 blood tests over the past 4 years, I’m able to make hypotheses aimed at the role of my diet on optimizing my biomarkers.

I track resting heart rate (RHR), heart rate variability (HRV), and sleep stages with a wearable on my wrist, and my goal is to get my RHR to ~40 beats per minute, and to have HRV and the amount of deep sleep as high as possible. Since I’ve been wearing the fitness tracker, I’ve reduced my RHR, and within the past 2 months, significantly increased my HRV. Deep sleep seems to be more difficult to improve, but I’m actively working on different things to try to optimize that, too. I’m not shy about sharing any of my data, and there are lots of posts about that on my blog.

What are your thoughts on biological age testing? Which tests (epigenetic, blood biomarkers, telomere, etc) and specific services do you believe to be most useful?

I’m a huge proponent of biological age testing. I also have many articles about this on my site, including aging.ai, phenotypic age, and epigenetic clocks. The phenotypic age calculator is pretty good when compared with the gold standard of epigenetic testing, but costs 4x less and is much easier to decipher. Plus it’s based on 50-100 years+ of research for each component (i.e. CRP, albumin, etc.), so knowing how its variables change with age and what’s optimal for health are more clear. There’s far less data on the epigenetic clock (< 10 years), in contrast.

First, aging and disease are biochemical processes. Tracking internal measures of health is an important strategy for slowing both, and accordingly, the ability to blood test repeatedly, many times per year is essential to my approach.

What else is in your biohacking stack? (Nutrition / diet, fasting, wearables or other products, fitness routines, supplements, drugs, services, lifestyle practices, sleep, mental health, etc. The more specific the better.)

I have a wrist wearable that tracks heart rate variability, resting heart rate (and average daily HR), and sleep stages. I do structured exercise (weights/core/stretching) 3-4d/week, and for ~1hr each session, and I walk 15-20 miles/week. For supplements, 1000 IU of Vitamin D in the winter, as that keeps me above 30 ng/mL, and a B6-methyl folate-methyl B12 stack that has a small, but positive impact on my homocysteine levels. In terms of nutrition, I shoot for ~5-10% caloric restriction, and more specifically, I have posts on my site about my macros- and micros, and the average composition of my diet. I’m constantly making adjustments to my diet to attempt to positively affect my circulating biomarkers, which I measure 4-6x/year. Sleep is super important, and I’m obsessed with getting enough deep sleep every night, and which components can help me optimize that, especially considering that less deep sleep is linked with Alzheimer’s disease risk.

What is the one biohack that had the biggest impact on your life?

It’s a combination of blood testing and my wearable fitness tracker. First, aging and disease are biochemical processes. Tracking internal measures of health is an important strategy for slowing both, and accordingly, the ability to blood test repeatedly, many times per year is essential to my approach. Using that approach, it’s less likely that I’ll end up with CVD, cancer, or any other disease, as I should be able to see deviations in my blood biomarkers first before a significant problem arises. Second, I’ve always been relatively lean and fit for most of my life, but I had never tracked my RHR, HRV, or sleep stages. Since I’ve been tracking those, I’ve make significant gains for each (for more info, see the many posts on my website), and I feel better because of it, too. So less overtrained, more fitness gains. Consider this: exercise is well known to increase average, but not maximal lifespan, so there’s obviously something about exercise that is simultaneously good and bad for longevity. By tracking my fitness metrics and my circulating biomarkers, I hope to increase both average and maximal lifespan. Not being overtrained is likely a big part of that.

What developments in longevity / human microbiome / health optimization are you most excited about? Do you have a personal longevity goal?

The ability of AI to integrate as much clinical data as possible with lead to great advancements in health optimization, disease risk, and longevity. Also, I expect that vaccination for microbes that commonly affect older adults, like CMV, and the other herpes viruses (HSV-1, HSV-2, etc.) will further achieve health+longevity gains. However, note that despite 40+ years of research for a CMV vaccine, it still doesn’t exist. AI will also dramatically improve vaccine development. My personal longevity goal is to live longer than everyone that has ever lived. The current record is 122 years, so beating that is my #1 goal. Inherent in that is being as fit and lean on the outside and inside (through biomarker testing) as I was at 20 years old. I hate the idea of being less functional at any age!

Where can people find more about you and your work?

Many places! My website, michaellustgarten.com, on Facebook (@mike.lustgarten), Twitter (@mike_lustgarten), and for those interested in donating to the cause, my university page (https://hnrca.tufts.edu/research/labs/nutrition-exercise-physiology-sarcopenia-neps/michael-lustgarten-ph-d/).

Do you work or do research in aging, longevity, or biohacking? Want to be featured on Biohack Stack Interviews? Contact me at nathan (at) biohackstack.com