A couple of weeks ago, I wrote about obesity and the concept of evolutionary mismatch. As always, I posted it up on my Biome Buzz Facebook page. A few days later, in response to a comment that the whole problem is nothing more than glyphosate, another Facebook user wrote, “Reductionism is never helpful.” Not to make a bad pun here (well…kinda to make a bad pun!): he reduced this issue to 4 perfect words.
The question of what is causing the epidemics of obesity, autism, allergy, autoimmune diseases, etc. in the industrialized world is unbelievably complicated and involves bodily processes that may not have been discovered yet, let alone, we still have no idea what outside influences might be involved or how much influence they may have. We don’t even yet know fully how our immune system works, let alone how all the trillions of organisms in and on us affect each other and our bodies, what part the foods we eat plays – and the toxins we come into contact with, the lifestyle factors, etc.
We have to accept that there is no single or simple answer to these questions. Period.
Years ago, I gave a joint talk with a medical professional who used the following 3 slides to try to express to our audience just how complex the human immune system is – let alone the entire rest of the body.
While I try to make the science I read understandable for us lay people, the reality is, there is nothing simple about it at all.
A few articles in the last few days exemplify this point. Over the weekend, as one example, I read an article on the Conversation that looks at the bad and good of antibiotics.[i] The article points out, “In the past decade, we have become more aware of the health-promoting characteristics of the microorganisms that live on and in our bodies – the microbiome. For example, a diverse and stable gut microbiome is necessary for digestion and protection against gut infections. Changing the microbiome with antibiotics can be helpful…but also harmful.” The author points out that in animal studies, antibiotics – by altering the gut bacteria – have been found to be responsible for weight gain and adverse metabolic effects; for poor immune response to cancer; and with the development of depression.
Conversely, antibiotics also save millions of lives every day and more than that, scientists have found they often do as much good as they do bad: “More than six decades ago, researchers first noticed that certain antibiotics had beneficial effects that were not explained by killing bacteria.” 60+ years ago, scientists noticed that prontosil, one of the first antibiotics, improved the functioning of immune cells responsible for killing bacteria. A recent review of 10 clinical trials of antibiotics showed that they can promote child growth in those with infectious diseases and malnutrition. Another antibiotic called cotrimoxazole promotes health and is frequently used in those with HIV to block infection and persistent inflammation. In a randomized, controlled trial conducted on children with HIV in Africa, those taking the antibiotics had improvements in systemic inflammation, including in the gut. The authors of this article, who ran this study, surmised that the antibiotic reduced inflammation in 3 ways: “One, it suppressed a group of gut bacteria called viridans group streptococci, which trigger gut inflammation. Two, it directly reduced harmful activation of blood immune cells. And, three, it blocked inflammatory signals from gut cells.” No one yet knows fully the mechanism of action but the fact remains, the medications are doing something beneficial.
The author concludes, “To guide better antibiotic choices, we need to look deeper than just their effects on infections that make us sick into the underlying body processes they can change. As antibiotic use continues to expand and change worldwide, its time we understood more fully how they work.” Well, amen to that. The fact is, how they work, what exactly they are doing in us, etc. is not even vaguely as simple as “they kill bacteria.”
A second example of the incredible complexity involved in researching chronic diseases was provided by an article I posted on Facebook from Medscape a few days ago: “New Approaches Targeting the Microbiome in CV Disease.”[ii] The article describes a review from the Journal of the American College of Cardiology on the relationship of the bacterial microbiome to the development of cardiovascular illness. “While previous studies have focused on what specific organisms are implicated, we are beginning to realize that it is their balance of the ecosystem within the body that creates an environment that protects or promotes various cardiovascular diseases…” That is, it’s the balance of the entire body and its biome that is important – not just the individual organisms that live in us.
The lead author of the review, Dr. Tang, states that “…prior studies have hypothesized that specific bacteria may directly promote pathophysiologic processes, and that by eliminating them with antibiotics, might lead to fewer adverse events. This approach has not worked because the underlying mechanisms were poorly understood, and there is an assumption of one-size-fits-all…Now we appreciate that much of our gut bacteria are likely beneficial and their compositions in our healthy gut are often difficult to alter, yet their metabolism can be modulated by dietary exposures that are unique across individuals.”
In fact, diet is one of the biggest environmental exposures humans have, but again remember that ONE SIZE DOES NOT FIT ALL! “Unique across individual.” Says Dr. Tang, “…the concept of classifying food groups or diets as ‘good’ or ‘bad’ for health is somewhat outdated, since it depends largely on how nutrients are digested and interact with the body’s gut bacteria…”
It gets even more complicated than that! To quote Dr. Tang again, “Individuals can have vastly different gut bacterial compositions, so the same food may have different short- and long-term effects in different persons…This is further complicated by the fact that we all have our own unique physiological response to nutrients and metabolites independent of our gut microbiome.” Remember a couple of years ago, when a study in Cell Metabolism found that people respond differently to white versus whole wheat bread? Some people actually had a lower glycemic response to white, shocking the scientists…who found the response was actually tied into the composition of the gut flora.[iii]
So no! We cannot reduce the discussion of “why is heart disease so much more common today than in the past” to any one factor. It is not “diet” or “toxins” or “weight.” It is complex interplay of factors many of which we probably haven’t even yet discovered.
Dr. Tang points out that this why studies so often have contrasting results: we have not as yet learned out to account for individual microbiomes and individual physiological responses. In the future though, as we learn more, we can hope that personalized therapies in terms of diet, probiotics, prebiotics and on will become the norm.
So please: do not think that because becoming vegan, or following a paleo diet, or giving up carbs, etc. has made you feel like a million bucks that it is right for everyone. Do not think that toxins are THE answer, or that a probiotic that has worked for you is right for everyone. There is no such thing as one truth.